Tri Talk Triathlon Podcast

The audio for this podcast can be listened to here.

The website referred to in this podcast can be found here.
The surprising link between running economy and range of motion, significant variation of rolling resistance between tire brands, and hard numbers around the use of latex innertubes. It’s flexibility, rubber, and latex. No kidding. Today, on Tri Talk.

Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. To new listeners in Uruguay and Hawaii, I hope you are enjoying the ride. In Uruguay, I am impressed with the triathlon community that it established in that country. Keep us the great work. In Hawaii, I’m embarrassed to confess to you that up to the age of 30, I thought that pineapples grew on trees. Please forgive me. My goal at Tri Talk is to help you swim, bike, and run faster, to meet your personal triathlon goals. Whether you are an elite or amateur triathlete, we cover sprint distance to Ironman distance. I’m your host, David Warden, and this is Tri Talk Episode 64.

Today on Tri Talk it’s classic physics and physiology, the scientific comfort food of the triathlete. I’ll be covering some very interesting data regarding the specific costs of rolling resistance by tire brand and width. Some of the data is reassuring, and some of it is disturbing. Plus, is it worth dropping $10 on an innertube? We’ll find out with a look at the speed advantages of latex innertubes. Finally, flexibility is always good right? Right? It turns out that it depends on you goals as an athlete

This episode is sponsored by PowerTri.com. Right now at PowerTri.com you can buy the Rinse-n-Ride T1 Transition Footpool. It has happened to all of us. You come out of the water, run to your bike, and your feet are covered in sand or rocks. You wipe them down as best you can, put on your shoes, only to discover 3 miles into the bike the rocks and pebbles still embedded in your feet. Keep your feet clean and comfy by quickly dipping them into this small, inflatable, portable pool of water. Faster and much more effective than toweling you feet. Check it out today at PowerTri.com.

Don’t forget to visit Tri-Talk.com to check out the Tri Talk forums, read past episode transcripts, plan nutrition intake for your next race with the Nutrition Calculator, or watch some training video.

In episode 63 we discussed the risks of going too hard on the swim, particularly in a sprint-distance event. One listener, William Jenks, pointed out an error on my part when I delivered that information. I frequently used the term “effort” instead of the term “velocity”. The researchers who tested the triathletes were very specific that they had the triathletes swim at 3 different velocities, not 3 different efforts. William reminded me that there is not a linear relationship between effort and velocity. When the researchers found that an 85% velocity was the best velocity for a sprint-distance event, that does not mean the athlete should aim for 85% effort, a term I misused in the podast. 85% velocity might only be 80% effort. Each triathlete needs to time their individual sprint-distance time trial, use that as a 100% velocity base-line, and then aim for 85% of that velocity, not 85% of that effort. Thanks, William for keeping me in check.

Also from episode 63 we looked at performance gains from swim apparel, specifically a speedo vs. a speed suit, with the speed suit coming out ahead by 19 seconds over 750 meters. Carl from Toronto asked if the study done considered any body hair on the athletes, as the speed suit would have covered that hair. Perhaps shaving the chest, back and thighs of an athlete would have the same 19-second advantage as covering that surface area with a speedsuit. Sadly, the study did not discuss how hairy the athletes were, only saying that the subjects were elite triatheltes, but it is a good point. Given the choice between shaving half of your body, or donning a speedsuit, I’d still pick the speedsuit.

Let’s get onto the good stuff! I came across a fascinating report from a site called biketechreview.com. If you have a chance, take some time to visit this site. This is not a commercial for these guys, I have no idea who they are, but I am impressed with what they have done. One of their forums users took the time to test the rolling resistance of dozens of tire brands. A reminder that rolling resistance, which sometimes called rolling friction or rolling drag, is the resistance that occurs when a round object such as a ball or tire rolls on a surface. It is caused by the deformation of the object, the deformation of the surface, or both. The simplest definition is that rolling resistance is the amount of energy required to overcome the friction between the road and tire.

A common misconception on rolling resistance is that to overcome it, you need to have 19mm wide tires and pump up the tire to the maximum PSI, thus reducing the contact patch between the road and the tire. When overcoming rolling resistance, the goal is for the tire to maintain a small but constant contact patch to the ground that can absorb the forces applied to it. Skinny tires with high PSI tend to lose contact frequently, and can’t absorb the forces placed on it as well as a wider tire with some give from a lower PSI. Of course, like anything else, more is not better, and this does not mean that a PSI of 90 is better than a PSI of 130. 120 is widely considered the optimal PSI to minimize rolling resistance.

Also, clincher tires almost universally have less rolling resistance than tubular tires. If you were to take a cross section of a tubular tire mounted on a wheel, you would essentially see a garden hose. If you were to take a cross section of a clincher on a wheel, you would see that the shape is more of a U, as the tire has to constrict at the rim to hook under the rim wheel. That U-shape in a clincher result in less rolling resistance that the perfectly round tubular. Does that mean that clinchers are superior to tubulars? Not necessarily, but I’ll cover that later on in the podcast.

What was most interesting to me from this rolling resistance report was the confirmation that not all tires are created equal. Some have the ability to maintain their shape much better, or have a stiffer sidewall, and the difference in rolling resistance is much more than I thought.

For example, the tire tested with the lowest rolling resistance was the FMB Silk Tubular, which is a bit surprising because it is a tubular, and I would have expected clincher. But, it was one of the only silk tires tested, and was also a very wide tire at 24mm wide. It’s rolling resistance coefficient was 0.00240. To give you an idea of what this means in terms of watts on the bike, if we were to take a trained cyclist, in a good aero position, 180 pounds total weight for bike, rider, fluids, the whole package on the bike, at sea level air density on a flat course, to maintain 24.6 miles per hour would take 340.4 watts.

Compare that to another popular triathlon tire, the Continental Competition tubular, 22mm wide. The rolling resistance coefficient on that tire is 0.00340, which for that same rider on the same wheel in the same aero position would take 349.3 watts to maintain that same 24.6 miles per hour. I find this very disturbing because this is the tire I race on my front wheel, and I race with a 19mm tire as opposed to the 22mm tested, which means the rolling resistance is probably even higher than that 0.00340.

But, I’m not totally depressed, because my back wheel has a Vittoria EVO Corsa tubular, with a rolling resistance of 0.00275, placing it at only 343 watts to maintain that 24.6 miles per hour, just 3 watts off the fastest tire tested. There is also another catch to this test which I’ll go over in a few minutes.

But 11 of the top 12 tires tested are not tubular, they are clincher. The clincher tested with the least rolling resistance was the Vittoria Ultra Speed, which unfortunately is no longer made by Vittoria. The next lowest rolling resistance, which is still easy to find is the Bontrager Race X Lite Pro, 23mm wide, with a rolling resistance coefficient of only 0.00244, requiring just 340.8 watts, or half a watt more than the top tire tested.

Another tire that was tested frequently, with different widths, that consistently came up on top was the Michelin Pro Light and Michelin Pro 2 Light. These tires at any width just dominated the low rolling resistance, with no tire having a resistance greater than 0.003. What is interesting is the Michelin Pro Race series was one of the worst across the board. Michelin makes both the Light series of tires and the Race series, and that Race series does not do well on these tests, but the Light series performs very well.

The Zipp clincher was another good choice, with a 0.00275 coefficient, requiring 343 watts. Overall, however, Michelin, Vittoria, and Bontrager at all widths dominated the top 20 in terms of rolling resistance.

But, there is more data to this that makes a huge difference. These tests were all done with latex tubes in the clinchers. 99% of all tubes that you’ll find in a bike store are the butyl tubes, not latex. In fact, the only makes of latex tubes I know if is Michelin, and at $10 a pop, it is heart-breaking to get a pinch flat when mounting them to your tire. There were some limited tests done with the same clincher tire, but comparing butyl and latex tubes.

Let’s look at that all-around good rolling resistance tire, the Michelin Pro 2 Light. With a latex tube, a rolling resistance of 0.0026, or 342.7 watts using that same rider at 24.6 miler per hour. If you were to switch to a standard Bontrager butyl tube, your rolling resistance goes from 0.00266 to 0.00322, 347.7 watts. A full 5 watts slower, which would equal about 9 seconds over a 40K time trial. At 2 latex tubes at $10 a piece, that is a couple of dollars per second, not the biggest bang for your buck, but definitely a low-cost way to gain 5 watts of power. The report tested several other tires using butyl or latex, and the results were the same, about a 5 watt gain in power from using the latex tubes over the butyl.

Basically, any advantage that clinchers have over tubulars in terms of rolling resistance is wiped out unless you use the latex inner tubes. You can do a search on the internet for latext tubes and cycling, and you’ll find various on-line retailers who carry latex tubes. I wish I could say that PowerTri.com carries them, but they don’t yet. I can tell you that PowerTri.com does sell Vittoria tires, which were one of the best tires tested in this report.

Now, based on this information, should you go out and sell your tubular wheels and go back to clinchers? This data is telling us that we can put out 3-9 watts more if we use a clincher with a latext tube. Here is why I’m not switching:

Wheel weight. While a clincher tire might have lower rolling resistance over a tubular tire, a tubular wheel has a significant weight advantage over a clincher wheel. Since a tubular is glued on, it does not require that extra hook system the outside of a clincher rim requires. That extra rim material can add several hundred grams of weight to the wheel, and it is adding it to the worst part of the bike: the very outside of the wheels where the rotational inertia means that weight is more significant than anywhere else on the bike or rider. A 500 gram difference between two sets of wheels will cost a trained cyclists 20 seconds over 40K. Let’s make that more reasonable and say that a clincher wheelset is 250 grams heavier, and drop that down to 10 seconds. We know that 5 watts for our test cyclist was 9 seconds, and to me the benefit from low rolling resistance matched by the benefit from wheel weight. Plus, as soon as you hit the hills, rolling resistance won’t change, but your wheel weight will suddenly make a significant difference when climbing. That is why the tie-breaker to me goes to the tubular.

It is also interesting to consider the weight of the tires as well. For example, the Bontrager Race Light Tubular weighs in at 300 grams, compared to the Vittoria Triathlon EVO weighing in at only 190 grams. While both have similar rolling resistance ratings, That is 220 grams over both wheels, and that is a 10-second difference just between tubular wheels in terms of weight.

All tests were done at 120 PSI in an admirably controlled environment. You can read this report yourself by visiting the Tri Talk blog and clicking on the URL at the top episode 64, I’d read it to you on the podcast, but the URL is just too long. It is kind of interesting to look up and see if your tire is listed, and where it turns up on the list. This report was done by a gentleman named Al Morrison, and it must have taken and incredible amount of work. Al, wherever and whoever you are, you have done a great service to the triathlon community.

Two weeks ago Joe Friel presented a live e-clinic on how to pace for a steady state event such as a triathlon. If you missed that 1-hour presentation, don’t worry, we recorded it! Just go to TrainingBible.com and click on Camps and Clinics to find out how you can access this webinar. Also, while you are there, register for the upcoming live TrainingBible Coaching webinar on Aug 27th discussing the Paleo Diets for Athletes. Presented by Kelly Cawthorn, this live presentation will include a Q&A session at the end. This is your chance to learn from the expert how to apply Paleo Diet to your training plan and lifestyle.

Moving on. This next topic might ruffle a few feathers. Back in episode 36 I discussed two studies on the effects of flexibility. One concluded that flexibility was linked to decreased risk for injury, and another linked flexibility to increased strength and endurance. Those 3 reasons alone: injury prevention, strength and endurance, were enough to convince me to adopt a more aggressive flexibility routine. However, none of these studies actually linked flexibility to speed. Let’s take a look at a couple of other studies on flexibility and running economy.

The first study from the Int J Sports Med took 34 elite international distance runners and compared their running economy to the sit and reach test. This test will test the flexibility of the hamstrings and lower back. Each runner had their running economy tested at 16kph, or in other words how much of their VO2max were they using at that speed. A lower VO2max for the same given speed would mean better running economy.

The researchers found no relationship between running economy and weight, height, or age. Of course, since all 34 were elite international runners, it goes without saying that they had to all be young and lightweight. The only correlation that the researchers could find between these 34 runners and their running economy was their flexibility.

The runners with the worst sit and reach scores had the best running economy. The researchers concluded that, “stiffer musculotendinous structures reduce the aerobic demand of submaximal running by facilitating a greater elastic energy return during the shortening phase of the stretch-shortening cycle.”

OK, so maybe you are thinking that this only applies to elite runners. They are so fast that flexibility has no meaning at their level. Well, another study from the University of North Carolina took 19 well-trained but not elite 10k runners and assessed 9 measures of flexibility after a 10-minute warmup. They then performed 2 running economy sessions. Once again, even at the age-grouper level, there was no correlation between economy and flexibility. Again, of the 9 flexibility measurements, 2 of the 9 showed an inverse relationship. The less flexible the runners were in their dorsiflexion and hip rotation, the more economical they ran. These researchers also concluded that, “these results suggest that inflexibility in certain areas of the musculoskeletal system may enhance running economy in sub-elite male runners by increasing storage and return of elastic energy and minimizing the need for muscle-stabilizing activity.”

There was even a third study that was cited, but I could not find it. It claimed that 100 male and female subjects across a range of treadmill running speeds (0.9-3.13m per second), had a battery of 11 tests to assess trunk and lower limb flexibility. Analysis of the data revealed that subjects who exhibited tightness in the trunk (limiting turnout of the leg from the hip and trunk rotation) were the most economical at every test speed. Since I could not find the actual study or even the abstract for this, I’m not as confident as I am with the first two studies I discussed, but I still trust the source that cited it.

In summary, there is no study that I could find that links increased flexibility to increased speed or running economy. In fact, all the studies I found showed the opposite in terms of running economy. Now, one could argue that increased running economy does not necessarily mean increased speed. But this is a pretty weak argument to me. If someone can run at 16kph at 80% of their VO2max, vs someone running at that same speed at 85% of their VO2 max, all the first athlete has to do it go to 85% of their VO2max and they will pull ahead of the second runner. If running economy is not the holy grail of predicting run race performance, I don’t know what is.

However, I do believe that increased range of motion and flexibility is important in the following circumstances. First, in swimming, flexibility is critical. I don’t have anything yet to confirm this, but from what we know if the differences in swimming and running, I’m confident that this is the case. I do think that upper body stretching is important for swim performance. I don’t have an active upper body stretching routine, but after 10 years of putting on my own sunscreen on my back, I have managed to accidentally have great upper body flexibility.

Second, if you have a history of injury, or if avoiding injury is critical to you, continue with an aggressive stretching routine that targets those areas at risk. Missing 3-4 weeks of running from an injury does not seem worth any increase in running economy. But, if you have no history of injury, and you don’t stretch currently, maybe you are on the right track.

I recognize that at this moment, dozens of coaches are franticly loading their e-mail to write me. I hope this data is wrong, and that there is some data to backup flexibility and running economy. I just couldn’t find it.

That’s all for this month. Don’t forget to support Tri Talk by purchasing your very own Tri Talk CD, which includes all episodes not currently published on the podcast. Or, you can also download individual episodes for just a dollar. Visit PowerTri.com for your CD or electronic download. See you next time.

Int J Sports Med. 2002 Jan;23(1):40-3. Running economy is negatively related to sit-and-reach test performance in international-standard distance runners. Jones AM. Department of Exercise and Sport Science, Manchester Metropolitan University, Alsager, United Kingdom.

Med Sci Sports Exerc. 1996 Jun;28(6):737-43. The association between flexibility and running economy in sub-elite male distance runners. Craib MW, Mitchell VA, Fields KB, Cooper TR, Hopewell R, Morgan DW. Department of Exercise and Sport Science, University of North Carolina, Greensboro, USA.

The audio for this episode can be heard here.

How your swim pacing affects the rest of your race, specific performance gains from swim apparel, and is it ever too warm to wear a wetsuit? It’s a swim special edition, today on Tri Talk.

Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. New listeners since episode 62 hail from Kansas and Moscow, Russia. In Kansas, my guess is the increase in listeners comes from the upcoming 70.3 Ironman event less than a week away, best of luck to you at that event. When I saw my download stats I did a double-take assuming that Moscow meant Moscow, Idaho. But no, there are really new listeners from Russia, where I spent 6 unforgettable weeks in my youth. My goal at Tri Talk is to help you swim, bike, and run faster, to meet your personal triathlon goals. Whether you are an elite or amateur triathlete, we cover sprint distance to Ironman distance. I’m your host, David Warden, and this is Tri Talk Episode 63.

That was Os Improvaveis with Walking in the Sunshine, from podsafeaudio.com. I know that the last thing that those of you from the Midwest United States want to hear about right now is more water. If you are from that area and were caught in the middle of that terrible flooding, I wish you a quick recovery. Bear with me as we spend this episode exclusively on swim-related topics, that have, however, a direct impact on your bike and run as well. For example, in our lead topic we’ll find out if swim pacing has a much larger influence on your overall triathlon performance that you may have previously thought. We’ll also look at a study that places a specific time savings on wearing a speedsuit in the water, and the implications for wearing one out of the water. Finally, we’ll briefly look at some numbers around wearing a wetsuit in warm water, and if that leads to the risk of overheating.

This episode is sponsored by PowerTri.com. Right now at PowerTri.com, not only can you get 15% off regularly priced items using the discount code tritalk15, but now you can order the new Velotak bracket. Are you sick of trying to decide where to put your race number on your bike frame? Do you put it on the seat tube, the downtube, the top tube…and then trying to get that sticker off after the race with that messy sticky residue. No more with the Velotak bracket. The bracket attaches to the seat tube or top tube, then attach your number to the bracket. With a pivoting head, you can display your race number vertically or horizontally. You really have to see it to believe it. Check it out right now on the home page of PowerTri.com.

You can contact me at david@tri-talk.com, or better yet visit the Tri Talk forums off the Tri Talk home page and be a part of the Tri Talk community that has posted thousands and thousands of posts to help you swim, bike, and run faster. And while you are on the Tri Talk website, don’t forget to complete your Tri Talk collection by either downloading all the episodes individually, or purchasing your own CD. There are over 1,600 minutes of Tri Talk audio. That’s 27 hours, but 1,600 minutes sounds a lot better. All previous episodes are available for download all except for episode 1-17 because frankly they really, really sucked.

In triathlon news, I’m guessing that the increase in listeners from Russia had something to do with the drama surrounding which country would end up with 3 Olympic slots rather than two, with a virtual tie between the US, Russia, and Australia going into the final race to determine those slots. The dramatic ending to the men’s Olympic triathlon qualifying slots took place at the ITU World’s at Vancouver this past week-end. Congratulations to both Russia and the US for their strong finish, and squeaking in enough points to qualify 3 men for this summer’s Olympics. If you would have told me last year that Australia would only qualify 2 men’s slots into Beijing, I would have never believed you.

Episode 61 introduced Joe Friel’s decoupling protocol, and the feedback from that episode was significant. There are 2 particular comments on decoupling that came in I’d like to review. First, from Roger Behle of Anaheim Hills, California who writes:

“When testing for decoupling, what period of time should be allotted for warm-up? I raise this question because I have personally noticed a gradually increasing heart rate – sometimes lasting up to 30 minutes – before leveling off at a steady pace (running). I assume you would not want to include increases in heart rate attributable to warm-up when assessing decoupling.”

Roger brings up an excellent point, because since the decoupling protocol is based on the changing delta between Zone 2 HR and power output. An unusually high upward drift in HR during the first 30 minutes of warmup could artificially indicate high decoupling, when in fact it was only due to the time it took for the athlete to even initially reach Zone 2. There is a significant variation in the amount of time it takes an athlete to warmup. Some can do it in 10 minutes and some, like Roger take 30.

For athletes performing a 3-4 hour decoupling test, I would suggest very little warmup for 3 reasons. First, the test is so long that any front-loaded HR data will have minimal effect on the overall results. Second, performing a long warmup places the athlete at risk of fading too early in the protocol. A solid 30-minute warmup followed by a 4-hour ride could cause the rider to not be able to sustain as much power at the end of the test, and have artificially low power at the end. Third, dehydration is a large factor in cardiac drift, and that extra 30 minutes places you in a position to potentially be more dehydrated at the end of the test, elevating the HR.

For short decoupling tests of 1-2 hours, I don’t see a consequence of a Zone 1 warmup helping the athlete achieve high Zone 1 or low Zone 2 before officially starting the test. Particularly doing a warmup on the bike before performing the run. Great question, Roger.

Another comment came from my friend and former USAT Head Coach, Marc Evans who lists a few other snags with decoupling:

“1)Heart rate is NOT an absolute indicator of intensity. How, are athlete’s determining one 2? That’s a very difficult number to determine.
2)Dehydration during the second half of the test will affect Hrate.
3)Muscle glycogen at start
4)Sleep and rest before the test
5)Temperature and other environmental considerations such as humidity, pollution, inclement weather
6)Improvement or decreases in mobility, flexibility and core strength (those glutes we’ve talked about…)
7)Rest between workouts and pre-testing protocol so the results can be more consistent
8)Motivation

I respect the science and find it very interesting, but there are of course, many variables at play. Triathlete’s often hope for that “little blinking number” to tell them they’re on track with training.”

Thanks, Marc for your expertise and input. And by the way, the next time I have you assess my strength and mobility, you’re going to be amazed at my gluteus medius. My gluteus medius will become legendary within the medical community. In fact, I have already submitted a proposal to the American Medical Association to have the gluteus medias renamed to gluteus Warden-ius.

Also, I should point out that Roger Behle, who asked about decoupling and warm up, also pointed out that dehydration could skew the test in his e-mail to me.

Let’s get on to the good stuff, shall we? I’m going to relate a quick story of why I chose to research this next topic, and how it really hit home for me. I participated in a sprint triathlon this past week. I came into it with high expectations of finishing near the very top of the event. The course played to my strengths with a challenging canyon bike course, and a slightly shorter swim course than a typical sprint distance event.

However, the morning of the race, the weather was in the 40s and raining at the race. The race director’s decided, justifiably, to cancel the bike portion and make it just a swim-run. This was pretty devastating to me, because my swim is still my weakest sport, and I count on the bike to get myself back into position in the race. I had been popping off all week about how well I was going to finish the race, my 2 brothers had come to watch me race, one all the way from Hong Kong. Those of you with brothers know exactly how competitive that can be. I was determined to finish as strong as I had predicted.

So, I decided I had to go all out on the swim, holding nothing back. The result was excellent, a full minute faster than I had done in the past at that same distance. However, when I hit the run, everything fell apart. And we are only talking about a 5k run here. The whole race took less than 30 minutes, but I literally bonked on the run. So what happened?

Well, lot’s of things could have happened, but the following is a fascinating study on how swim intensity affects your overall triathlon performance.

A study by the University of Western Australia had 9 skilled triathletes perform a 750-meter swim time trial to establish their fastest swim pace for that distance. That 750-meters is, of course, the typical true sprint-distance swim length. Having established their swim time trial at that distance, the triathletes performed 3 sprint-distance triathlons in a controlled environment, but with varying swim pacing before the 3 triathlons. The 3 paces were at 80-85% of the time trial velocity, 90-95% of the time trial velocity, and 98-102% of the time trial velocity. We’ll refer to them as S80, S90, and S100.

The times for S80, S90, and S100 were 734, 673, and 619 seconds respectively. S80 was a full 114 seconds slower than S100, and over a minute slower than S90. Initially, you might be thinking what I am thinking, “hey, I can be a full 2 minutes faster if I lay it all out on the swim!”

But, the subsequent cycle times were very interesting. S80, S90, and S100 were 1654, 1682, and 1808 seconds respectively. Meaning, the cycling time after the 80% swim effort was 154 seconds faster than the cycle time after the S100 effort on the swim. The S90 was 126 seconds faster than the S100. The researchers concluded that the difference between the S80 and S90 cycling efforts was not statistically significant, but that the difference between either the S80 or the S90 and the S100 was statistically significant.

So, at this point we might be saying, since both the S80 and S90 are statistically the same result on the bike, the S90 should be the best swim effort because it had a one-minute advantage over the S80 on the swim. We’ll come back to that.

Let’s add the run onto these sprint tests. There was a difference in run performance, again with the faster run times occurring after the slower swim efforts. But, the difference in run times between the 3 trials was not statistically significant, and the researchers rightfully concluded that the run was unaffected by the swim intensity.

However, when it came to the mean overall triathlon times for S80, S90, and S100 there is where the real good stuff is. The times were 3658, 3681, and 3763 seconds respectively. The S80 was a full 105 seconds faster for the overall event than the S100. Even though the S100 was almost 2 minutes faster than the S80 on the swim, those 2 minutes were easily gobbled up by the decreased performance on the combined bike and run. Again, while there was not enough of a delta on the run between the 3 swim intensities, there was enough of a statistical difference on the combined bike and run for the researchers to conclude that the S80 swim intensity was significantly higher than the S100. Also the researchers noted that overall triathlon time of the S90 was faster than the S100, it was not enough of a difference, and therefore the only statistical improvement in performance came from the S80 swim effort.

How do we apply this to our training? First of all, I think that this means we need to practice swimming at 85% of our time-trial effort for sprint-distance racing, and to do that, we need to test a 750-meter time-trial frequently to know what 85% of that is.

One of the theories from these same researchers was that going beyond a lactic threshold too early, even only for a short period of time, places the athlete at a serious disadvantage for the remainder of the race. The researches noted another study which had shown that intense arm exercise that raises circulating lactate concentrations can impair subsequent leg exercise, and this is one of the primary reasons for the case of the negative split. Going out too hard early taxes your system too high, and it can’t recover. To review really quick, a negative split refers to finishing the second half of a steady-state endurance event faster than the first half.

But this study makes me think of a negative split not just in terms of a negative split for a single discipline, but a negative split strategy for the entire race. Meaning, maybe we should not be looking to negative split the swim, and then negative split the bike, and then negative splint the run, but rather look at your entire race as one big negative split. Treat the swim and first half of the bike as one lap, and the remainder of the bike and run as the second half of that negative split. I have not specific research on this, but I would imagine that even swimming the second half of the swim at high levels of lactic concentrations could result in similar consequences on the overall race to what we saw with the entire swim at high intensity.

Does this apply to longer swim distances? Does this mean 85% intensity is the optimal swim intensity for all distances? Probably not. Although this is good evidence for sprint distance events, 90% effort of a 1,500-meter time trial pace is going to be much less than 90% of a 750-meter time trial pace. Or, on the extreme, 90% of your Ironman swim pace is probably well below lactic threshold, whereas 90% of 750-meter pace is probably at or above your threshold. I feel like it is safer to push the percentage higher of your time trial pace for the longer swim events. The key is to find a pace that is below your lactate threshold. For sprint distance, I’m liking this 85% number.

One last thing on this study. The overall power outputs on the bike for S80, S90, and S100 were 304, 298, and then it dropped all the way down to 278 watts for the S100.

Before we move onto the next topic, I have a question for you. As a coach and athlete, can you guess what piece of training equipment I access more than any other? If you guessed a HR monitor, a bike or shoes, you’d be wrong. The number-one piece of equipment I use is TrainingPeaks.com. Not a day goes by that I am not taking advantage of the features of TrainingPeaks.com. No more spreadsheets or carrying around copies of training books, or looking up workouts in training magazines. I can schedule my annual, weekly, and daily training plan. Create and store my own workouts or use the workouts in their amazing workout library. Historical reports and workout reminders from automated e-mails. Nutrition planning. Upload and analyze your workouts from devices such as Garmin, Polar, SRM, Nike, Timex, Computrainer, Cateye and many more. Whether you are a coach or a self-coached athlete, spend your time time planning and analyzing more efficiently with TrainingPeaks.com. Signup today for a free 7-day trial.

I have two more quick swim studies I wanted to share with you. This first one is sort of a followup from last week, where I discussed the interesting wind tunnel test from one athlete who shaved 80 seconds off of his 40K time trial just by switching from a two-piece tri top and bottom to a one-piece suit. Yes, all of the speed-suit manufacturers claim that their suit will make you faster on the swim. There is also a ton of interest in the Speedo skin suits because some swimmers are complaining to FINA, the world governing body for swimming, that the suits are so fast that they introduce an unfair advantage.

It was nice to find a study that actually looked at the performance of a skin suit to contemporary race apparel on the swim. In this study, published just last year in the Journal of Science and Medicine in Sport, researchers took 8 triatheltes and compared a swim brief, basically a Speedo, to a modern speed suit. Again, just like the last study, this was done over a 750-meter time trial. The speed suit was 19 seconds faster than the racing brief. Not a huge difference, but considering it costs about $200 for a decent speed suit, that is only about $5 per seconds saved if we can assume 38 seconds over a 1,500 meter time trial. But, only for indoor or warm water swims when you don’t have a wetsuit.

I keep coming back to the notion that although the speed suits were designed for increased speed in the water, can I assume at least some improvement on the bike wearing the speed suit? The only concrete data I have is from that one wind-tunnel test on one athlete, but the concept makes sense. Yes, water has much more drag than air, but did you know that because you are going so much faster on the bike and exposing so much more surface area due to positioning than on the swim, that the drag co-efficient for a swimmer and cyclist are almost the same? Drag plays every bit as much a role in cycling as swimming, and again I can’t help but think that the design for decreased drag in the water translates onto the bike.

Let’s look at it this way. If you save 19 seconds over 750 meters of swimming as this last study proved, let’s assume 19 seconds for every 15 minutes of swimming, which is 76 seconds per hour.

Now, how much did the athlete save over an hour time trial in the wind tunnel from wearing a one piece? 80 seconds, or 20 seconds per 15 minutes. At the very least, that is a curious coincidence.
By the way, I need to thank Tri Talk listener Martin Thow from Australia for sending me this study.

All right, one more swim study. I decided to research this study because of some concern that swimming with a wetsuit in relatively warm water put the athlete in danger of overheating, either on the swim or with overheating consequences later on the bike or run. Some athletes were choosing to not wear a wetsuit in water that was below the legal wetsuit temperature threshold of 78 degrees F.

It is likely that if you are swimming in water that is let’s say, 77 degrees F, that the ambient temperature that you will be cycling and running in is probably going to be much higher than 77 degrees at some point during the race, so I can see why this would be a concern.

A study published in Medicine and Science in Sports and Exercise took 5 male triatheltes and had them perform two Olympic-distance triathlons in a controlled environment. For both swims, the triathletes swam in 25.4 degrees C, which is just below 78 degrees F, for 30 minutes in a flume. One swim was performed with a neoprene wetsuit, and the other a regular swim suit. The bike and run portion of the race were performed in a hot and humid environment at 89.6 degrees, just below 90 degrees F with 65% relative humidity, which is pretty dang humid. It’s pretty rare that an athlete will come out of the water and immediately start racing at 90 degrees.

During the entire triathlon, core body temperature did not differ between the wetsuit and swimsuit tests. However, skin temperature was higher during the swim portion of the test when wearing the wetsuit by about 4 degrees C. But, by 15 minutes into the bike this temperature difference had dissipated, and temperatures stayed the same for the duration of the race for both the wetsuit and swimsuit tests. More importantly, there were no differences in VO2, heart rate, or rating of perceived exertion between the wetsuit and swimsuit tests. Additionally, no significant differences were found in cycling, running, or total triathlon times.

At least for Olympic distance racing or shorter, there appears to be very little risk of wearing a wetsuit in any temperature under that 78 degree limit. Even for half-Ironman racing, these athletes swam for 30 minutes, which is about the time it takes for a good swimmer to finish the 1.2 mile half-Ironman swim. My guess is that even for full Ironman racing, any overheating is also likely to be gone within 15 minutes on the bike. Unless you just hate wearing wetsuits in general, it looks like you are safe from overheating in wetsuit legal water temperature.

Thanks for listening to the podcast today. Before we end, I’d like to ask you to consider what would happen to you if you lost your site. This is the reality for over 10 million Americans who suffer from retinal degenerative diseases, such as retinitis pigmentosa, macular degeneration, and Usher Syndrome. There are currently 7 clinical trials in progress that are having amazing results. Imagine that we are only minutes away from curing these dreadful diseases. It goes far beyond blindness as most of the people who suffer from these diseases end up with severe depression and obesity. Please support our many athletes who are blind, or becoming blind from one of these conditions by either making a donation or consider racing for this amazing cause. If you have any questions or interest please visit www.racetocureblindness.org or contact Michael Stone, Ironman Triathlete at mstone@stonegrp.com. Michael also has one of these diseases and although still races as an age-group triathlete, this is a time bomb for him. Help Michael and other athletes by visiting racetocureblindness.org. Thanks for listening to the podcast, I’ll see you next time.

J Sci Med Sport. 2007 Oct;10(5):327-33.
Med Sci Sports Exerc. 1998 Jan;30(1):99-104.
British Journal of Sports Medicine 2005;39:960-964

The audio for this podcast can be listened to here.

Is your tri suit slowing you down? Results from 3 wind tunnel tests and what we can learn from them, and the rare swim condition known as SIPE. Plus, a brief review of the Women’s US Olympic Trials. It’s wind, water, and women…with a Warden, today on Tri Talk.

Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. Welcome to new listeners from Sweden and the one listener from Venezuela. In Sweden I hope you are ready for the Göteborg triathlon coming up on June 15. And in Venezuela, I’m positive I know who that listener is. It’s Hugo Chávez. I’m positive. Can’t you just see the guy in a wetsuit? My goal at Tri Talk is to help you swim, bike, and run faster, to meet your personal triathlon goals. Whether you are an elite or amateur triathlete, we cover sprint distance to Ironman distance. I’m your host, David Warden, and this is Tri Talk Episode 62.

That was Thinner from the Black Dahlias. Today I am excited to go over some wind tunnel data that was provided to me by Colorado Premier Training. Some of the data will strengthen what you already now about aerodynamics, and some of it will challenge what we thought we knew, plus a very interesting wind tunnel test on a piece of triathlon apparel. Also, it’s common to panic during an open water swim, particularly your first, but when the panic moves beyond psychological to physiological, it may be a rare condition known as SIPE. We’ll talk about this at the end of the show. Also, I want to let you know that during this episode I’ll be recording the entire show in one take. That’s right, no more using the crutch of covering up my mistakes by recording a section over again. I’ll be doing live play-by-play at a few major triathlon events this year, and there won’t be any “do-overs” there. Plus, if I ever want to break into radio, it’s time to step up to the plate and be a true professional. As a result, this episode could get ugly, but it’s for my own good.

This episode is sponsored by PowerTri.com. Right now you can get 15% off any regularly priced item at PowerTri.com by using the discount code tritalk15. Last episode I challenged you to contact me if you were not completely satisfied with your purchase from PowerTri.com, and I would force the owner, one of my coached athletes, to pay the price in his training volume. It’s been a month and tens of thousands of dollars worth of orders later, and no complaints. Needless to say, I’m a little disappointed. If you’re not satisfied with the color of the packing tape when your package arrives, you let me know and I’ll stick it to the owner. That’s 15% off any regularly priced item for Tri Talk listeners, use the discount code tritalk15.

Before we get onto the good stuff, I want to briefly talk about how impressed I was with the win of Julie Swail Ertel at the US Olympic Trials in Alabama a couple of weeks ago. I recognize a lot of Tri Talk listeners are from outside the US, but there is a lesson from this event that I think we can learn from.

I know that many of you race against yourself, and are satisfied with simply using races as a method to benchmark your own progress. But if you are like me, racing is all about establishing a pecking order and beating as many other guys as possible. Plus, I hope you can appreciate the pressure on me as training “expert” to be fast and get to the podium frequently.

What I learned from watching Julie Swail Ertel was the psychological importance of taking the lead. Julie stayed with the lead pack on the bike and came out of T2 much faster than her 10k pace. She shot out of there and was going hard for the first 100-200 meters, and opened a nice gap rest of the field. There is something to be said about holding onto first rather than catching up from second. In fact, Julie Swail Ertel has very little running background. The woman who came in second, Sarah Haskins Kortuem, attended the University of Tulsa with an athletic scholarship for cross country and track. You had Julie Swail Ertel, a swimmer and former Olympic Silver medallist in water polo, open up the gap on the run against the athlete with the strong running background. That gap seemed just too much. That little surge at the beginning of the run seemed to make off of the difference.

Now, very little of us will ever have the opportunity to lead a race. But, if you are racing for your age group, and you can identify your competition, consider the advantages of taking and holding the lead.

Let’s get onto the good stuff. I’m so grateful to Colorado Premier Training for getting me this information. What I have is the complete wind tunnel results from 3 athletes of various sizes and abilities.

Let’s begin with athlete #1. This cyclist has a good threshold of 350 watts. A reminder that when training with power, your intensity threshold is no longer measured in terms of HR, but in terms of watts. This athlete can maintain about 350 watts for an hour, so his threshold is 350 watts. 350 watts may seem pretty high, but this athlete is also pretty big. Your wattage output should be compared to your weight to determine if it is a “good” output or not. This athlete is big, but he is tall and lean. I’d estimate about 175 pounds and well over 6 feet. Hunter Allen and Andrew Coggan have a chart in their book Training and Racing with a Power Meter that looks at a weight to power ratio and takes that ratio to determine your cycling level. At 175 pounds, or 79.5 kilograms, this cyclist pushing 350 watts as a threshold has a weight to power ratio of 4.4, which according to Allen and Coggan, places him as a very good cyclist, about a Category 2 cyclist if using the categorization guidelines from USA Cycling. This would place this cyclist in about the top 5-10% of the cycling leg of any given triathlon.

Now that we know a little bit more about this cyclist, let’s look at the evolution of his positioning in the wind tunnel. Athlete #1 comes into the wind tunnel with a baseline speed of 44.17 kilometers per hour. That speed is based on his current drag in the tunnel and the assumption he can maintain that 350 watts over an hour. Over a shorter or longer distance, his wattage would obviously be different, but all the speed data we’ll be looking is based on wattage threshold, or an hour of cycling, or about an Olympic-distance triathlon cycling leg.

The first notable change is that the athlete raises his cockpit by 2cm, or just adding one more ring to the stack at the base of the stem. While one would expect the outcome to be a less aerodynamic position because he is up higher, the consequence is not that bad. Those 2cm change his speed from 44.17 to 44.12 kph, or costing him just 3.4 seconds over 40K. The take-home for me initially was that if this athlete is far more comfortable in the neck and shoulders at that slightly higher position, it may well be worth the 3.4 seconds to get into a more comfortable position where you can also potentially generate more power.

However, his next position is more significant. He then drops 4cm off of his cockpit from his original position. This changes his aerodynamics dramatically and increases his speed at that given 350 watts to 44.69 kph, which is a savings of 38.15 seconds over a 40K. That is a solid increase in speed. He then drops his position another 2cm for a total of a 6cm drop, which increases his speed even more saving him 65 seconds over 40k from dropping 6cm on the stem. For this athlete, if he can maintain power in that position, and is comfortable in that position, this is a very good change to gain 65 seconds in a race.

This athlete also experimented with what is known as the “turtle” position. This is where the athlete drops his head at the neck as low as possible. I find this position uncomfortable at best. The idea is to get your head as low as possible. This athlete was actually 6 seconds slower with the head on the turtle position compared to the 6cm drop with normal or natural head positioning.

Next, the cyclist rotated his hands in so that they were touching on the aerobars, and brought in the elbow pads a centimeter. Still with a 6cm drop up front, that narrower position actual lost 12 seconds. But, as soon as the athlete went into the turtle position, it became his fastest position of the day so far, shaving ½ of a second off the regular position with a 6cm drop. Let me repeat that. A 6cm drop with elbows and arms in normal position was ½ second slower than elbows in 1cm and head in the turtle position. For ½ of a second, I would imagine that this athlete would want to stay in the far more comfortable non-turtle, wider hands and elbows position.

So now this athlete is thinking they need to go to a 6cm drop for his best aerodynamics. Regardless of the head or arm positions, that 6cm drop has provided the best aerodynamic gains so far. But they decide to do one more test with a 2 cm drop. Astonishingly, that 2cm drop is faster than the 4 or 6cm drop. The 2cm drop is 40 seconds faster than the 6cm drop, and 106 seconds faster than the baseline position he came in with. It looks like the reason this is the best position for this athlete is due to the fact that he can maintain a flatter back with 2cm of drop compared to a more arched back with the 4 or 6cm drop. I know that everyone knows about Lance Armstrong’s hump, and how much faster it made him, but for this athlete, a less aggressive, flat back is more aerodynamic than the more aggressive 6cm drop with introduces a slightly arched back. It just goes to show that more is not always better, and having a huge drop in your cockpit is not always faster.

Another eye-opener on this athlete is helmet setup. This athlete used the Rudy Project helmet. I’m a big fan of Rudy Project sunglasses, but I have been skeptical of their helmet. It is so small compared to the other helmets. You might think that is good, but it reminds me of a thick tapered downtube compared to a small round downtube. The bigger, thick downtube is more aerodynamic, and the Rudy helmet seems too small to displace the air.

What the Rudy Project helmet does have is something called the Supercomp. This is an attachment to the helmet that covers the ears. They are also called “sideburns”. It significantly increases the surface area of the helmet. For this athlete, the difference between the sideburns on and off was 109 seconds. Don’t let anyone tell you that an aero helmet’s design does not make a difference! 109 seconds from adding a little piece over your ears.

Now, what I like about the Louis Garneau helmets is that the “sideburns” are built in, and the ears are well covered with the standard Rocket helmet.

So, this athlete was able to shave off 106 seconds from learning that a 2cm drop was his best change. Let’s say that he spent $1,000 for an hour in the tunnel, and another $500 in travel. That’s $14 per second saved, which places it as a more economical investment than either aero wheels or a tri bike. Essentially, $1,500 will get you either a nice set of aero wheels, or an hour in the wind tunnel with travel. The aero wheels will shave off 60 seconds or so, while the tunnel shaved 106 seconds off this athlete’s 40K. However, the obvious difference is that the aero wheels will almost universally save you about a minute, while the wind tunnel results will widely vary. It’s a risk/reward decision.

Let’s move onto athlete #2. This athlete has a threshold of 200 watts, but is a much smaller athlete. I’d say by looking at him only about 150 pounds. Based on Allen and Coggan’s power to weight ratio, this places this athlete at about a category 4 cyclist, or top 50% of the cycling leg in any given triathlon. Compared to the 45 kph from athlete #1, this athlete’s baseline is about 39kph over a 40k ride.

The first test with athlete #1 brings his reach back by 3cm, so that his elbows are much further behind his ears. This could be accomplished by reducing the stem length by 3cm. It makes almost no difference in his aerodynamics, but in fact makes him almost 7 seconds slower from shortening his cockpit. But, when the athlete goes into a turtle position and chokes up on the aerobars, he suddenly saves 118 seconds! That is 2 minutes from chocking up on the aerobars, or bringing the arms way in towards the body where the forearms are resting on the armpads closer to the wrists than the elbows, and lowering the head into that turtle position. So, that 3cm shorter cockpit was a detriment to him if he kept his elbows on the elbow pads, but was an aerodynamic advantage to him when he choked up and lowered his head.

This athlete then moved in the bars and elbow pads as close together as they would go. Now, for this athlete, although it was in as far in as they could go, they were not that far in. I would still not consider this an aggressive elbow and hand position, with the elbows still placed at shoulder width. But, his elbow position before was actual slightly wider than the shoulders. This other subtle changed shaved off another 38 seconds on top of the 118 he already gained from chocking up with a turtle position.

So, this athlete gained 151 seconds from his wind tunnel experience. For a $1,500 investment, that is less than $10 per second saved for this athlete.

One more fascinating result with this cyclist was that he also tested 2 other helmets. On this athlete, the LG Rocket helmet was 27 seconds faster than the Rudy helmet, but that is the Rudy helmet without the sideburns. If we can assume the same savings with the sideburns that we saw with athlete #1, the Rudy with sideburns would potentially be 82 seconds faster than the LG Rocket, but this is purely speculative. All we know is that the LG was faster than the Rudy on this athlete.

On to athlete #3. This athlete can push 300 watts for an hour, also averaging about 44kph. You might be saying, “hey how come athlete #1 could push 350 watts and athlete #3 is at 300, but they both have the same 40k velocity?” The answer is that athlete #3 came into the tunnel very aerodynamic already, with an initial drag coefficient much less than athlete #1. It is an interesting example that you can have two athletes be at the same speed, but have totally different wattage numbers because one is so much more aerodynamic than the other.

This athlete started by raising his cockpit by 3cm, with an unusual result of saving 14 seconds from going up 3cm. However, when dropping 2 and 4 cm, the athlete gained 37 and 52 seconds respectively. So again, a consistent increase in speed with at least a moderate cockpit drop.

The athlete then did an interesting experiment. He slid forward riding on the nose of the saddle and gained another second. Does not seem worth the discomfort.

The turtle position for this athlete did save 4 seconds. Interesting that both for athlete #1 and #3, the turtle position did not help much, but it seemed to make a huge difference for athlete #2.

Athlete #3 then experimented with different elbow and hands width positions. The first position was the pads 12cm apart and the extensions 6cm apart. The second was slightly wider, with the elbow pads 14cm apart and the extensions for the hands 8cm apart. There was less than a 4 second difference between the two positions. A third position placed the elbows actually touching, and that ended up being 14 seconds slower than having them 12cm apart. Again, a more aggressive position in arm width does not always lead to better aerodynamics.

Possibly the most fascinating experiment of all 3 was the athlete’s decision to test different sets of racing apparel.

Using arm covers, or sleeves that cover the arms from wrist to shoulder made absolutely no difference. No change at all with those arm covers.

But, the athlete did try cycling in both a cycling suit and a tri suit. Both appeared to be one piece suits. I wish I could tell you the brands of the clothing, but I only have these small pictures to go off of, and although I can identify the helmets, I can’t identify the clothing.

Anyway, the difference between the cycling suit and the tri suit was a whopping 80 seconds. That is a scary thought to me, that what you wear can have as much effect as the wheels, or an aero helmet, or positioning.

So, this athlete, by dropping 2cm and narrowing his arm width slightly was able to drop 55 seconds from his 40k time, or $27 per second on his $1,500 investment. If you count the alarming discovery that his tri suit was another 80 seconds slower, then he saved 135 seconds for the wind tunnel analysis, or just $11 per second saved.

By the way, this is the only wind tunnel test I am aware of that ties a specific aerodynamic consequence to different types of apparel. I’m sure someone else has done it, but I have not found one.

Back to the discussion of apparel, I would imagine that any one-piece tri suit that is truly a skin suit meant for improved water hydrodynamics, could be a good investment for the bike. This would include the Xterra Velocity , 2XU Kona Fusion, Blue Seventy Pointzero, the Ultra SpeedZoot, Sailfish Furious, DeSoto LiftFoil, and the Speedo Fastskin. These are not your basic one-piece tri suits, but represent true focus on hydrodynmics, which may or may not translate into aerodynamics. But, let’s imagine that it does. A $200 investment into one of these suits that might save you 80 seconds would be $2.5 per second saved, which is the same magnitude as an aerohelmet in terms of value. The disadvantage of these suits is that they are so aerodynamic, there are no pockets and there is no mesh material for venting. They are built for speed.

By the way, I love the DeSoto LiftFoil. It is the only tri suit I have used, so I can’t really compare it to the others, but it feels wicked fast for both swimming and cycling, and I look really good in it. Plus, you can get your LiftFoil from PowerTri.com.

Again, I have to thank Colorado Premier Training for providing me with this invaluable information. For more information on what Colorado Premier Training can do for you, or to get into their wind tunnel yourself, visit http://www.coloradopremiertraining.com

Before we move on, can I ask you: What do Conrad Stoltz, Xterra World Champion, Robin Benincasa, World Class Adventure Racer, John Howard, US Cycling Hall of Fame member, and other elite athletes all have in common? They are all breaking personal records and barriers with Acid Zapper. Acid Zapper is an all natural alkalizing sports supplement that breaks barriers that limit performance giving athletes a safe, legal, and effective edge. Acid Zapper is a product which truly deserves to be called a break through. For more information and to purchase go to Tri Talk.com and click on the Acid Zapper logo to see how you can break barriers too.

Moving on. I hesitate to even bring up this next subject. When I did a piece on hyponatremia, I got more e-mail from scared athletes than from any other subject. Should I drink? Should I not drink? What I failed to mention in that piece was that any well-trained athlete who has practiced nutrition in their training and sticks to that plan has an extremely low chance of developing hyponatrimia.

This next topic is exactly the same. Swimming Induced Pulmonary Edemia is very rare. The only reason I am even bringing it up is because one of my athletes had it happen recently, and so I did some research on it and felt it was at least worth a mention on the podcast.

I don’t know about you, but I don’t know any triathlete who did not have a bit of a panic attack the first time they swam head-down in open water. It is almost universal, even it if it lasts only a few moments, there is a big difference between swimming in the pool and swimming in the near pitch dark of open water. That sort of distress is common, and is usually easily overcome after a few minutes.

However, there is a more rare condition brought on from swimming that can have more serious results. Swimming Induced Pulmonary Edemia, or SIPE, is a pulmonary edemia, or a swelling or fluid in the lungs, brought on by swimming. It is caused when the blood gas barrier in the lungs fails under high pressure, and blood is allowed to flow back into the lungs. The bloog gas barrier in the lungs has a tough responsibility. It has to be thin so that gas can route from the lungs to the circulatory system, but it has to be strong enough so that under stress, that blood can’t get back into the lungs. This high-pressure condition is easily met when exercising in the water, as that extra pressure on the body tends to squeeze the blood into the weakest point of the circulatory system, the capillaries.

The most common symptom of SIPE includes coughing up pink, frothy spittle and mucus, which separates it from the more common panic attack of an open-water swim. Other symptoms include respiratory distress, wet-sounding popping or crackling in the lungs when breathing. These specific symptoms can help you determine the difference between normal open water distress and SIPE.

I would not have even brought this up were it not for a one piece of a study I found on SIPE that concerned me. A look at 70 cases of SIPE over 3 years was published by the Israeli army. They measured the oxygen saturation before and after the SIPE occurred. Before the attack, the swimmers oxygen saturation was 98 ± 1.7%. After the attack it was 88.4 ± 6.6%. Oxygen saturation is the measure of the amount of oxygen carried in the blood. Anything below 90% is considered clinical hypoxemia. I have a child who suffers from asthma, and from experience, I know that after a sever asthma attack, he can’t even leave the hospital until he is breathing on his own with 90% oxygen saturation. The fact that these swimmers were coming out of the water at 88% is alarming.

The whole reason I bring this up is to let you know that if you experience this problem, you should consider your day done. Being a hero and getting on the bike with the potential of a sub-90% oxygen saturation is an ugly prospect. Not only in terms of the rest of that day, but in terms of your recovery as well.

What can you do to avoid SIPE? It is really unknown but there seems to be good evidence that swimming on your back can attribute to this problem. Many athletes who start out with normal open-water distress naturally flip over to their back. The Israeli researchers hypothesize that this increases the pressure difference between the lower extremities and the thorax. Also being over-hydrated, and swimming in extra cold water.

Again, I don’t want you to worry about having a SIPE experience, I only want to let you know that if you ever do have it, remember to call it quits for the day.

Hey, I did it. One take, no stops. Bring on the music.

I want to provide a quick shout-out to my fantastic group of athletes. To Carl, John, Paula, Rob, Steve, Kim, Damon, and Darren, I just want to tell you how lucky I am to be able to coach you all. You are a fantastic and dedicated group of athletes.

A quick reminder that Tri Talk has moved to a monthly schedule for the race season. Look for episode 63 in June. Don’t forget, 15% at PowerTri.com. I’ll see you next time.

Swimming-Induced Pulmonary Edema. Clinical Presentation and Serial Lung Function
Yochai Adir, MD; Avi Shupak, MD; Amnon Gil, MD; Nir Peled, MD; Yoav Keynan, MD; Liran Domachevsky, MD and Daniel Weiler-Ravell, MD, FCCP

From IDF Medical Corps (Drs. Adir, Shupak, Gil, Peled, Keynan, and Domachevsky), Israel Naval Medical Institute; and the Division of Respiratory Physiology and Chest Disease (Dr. Weiler-Ravell), Carmel Medical Center, Haifa, Israel.