Tri Talk Triathlon Podcast

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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 podcast can be found here.

Don’t forget to take advantage of the free month of coaching from TrainingBible Coaching! Just fill out the application and tell them Tri Talk sent you, and they will waive the startup fee and give you a no-obligation no-contract free month of coaching.

Compression sock research and dimpled aero bottles. It’s aerodynamics, speed and spandex. A podcast for superheroes and triathletes! Today on Tri Talk.

Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. To the bulk of new listeners from Southern California and London, thanks for checking out the podcast. In Southern California, I’m getting excited for Ironman California just a few weeks away. You triathletes in San Diego have a great local coaching resource there in Jim Vance. In London, thanks for being the #1 Tri Talk demographic outside the US. 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 59.

Today on Tri Talk we are going to talk about specific data supporting compression socks. They were all the rage in Kona this year, and the image of Torbjorn Sindballe in his knee-high white compression socks running to a third-place podium finish certainly fueled even more interest. We’ll look at some studies on compression socks. Also, we know dimples help golf balls soar and even help aero wheels cut through the air, but what about dimples on water bottles? I was lucky enough to get some data tested by John Cobb on whether dimpled water bottles actually improved aerodynamics. Also, stick around later in the podcast to find out how you can get some incredible free one-on-one coaching.

Before we get onto the good stuff, I’d like to review some feedback from Episode 57 and 58. In my excitement from publishing that episode, I had billed it as possibly the best Tri Talk Episode ever. The feedback from you the listener was a resounding, “huh?”

From listener Phillip in the UK, he points out the difference between correlation and causation and observed the following:

“I just want to point out that a correlation does NOT imply a causation. It might help to prove causation, but not on its own. If A is correlated to B, it means just that - they are correlated. It does not prove A caused B in itself. For example, if you want to find out what causes house fires, you could try correlating “fires trucks in operation” to “fires that happen in a year”, for 100 cities. You’d find a positive correlation, but that does not prove that fire trucks cause fires”

Phillip also pointed me to a site that through the process of correlation could link global warming, earthquakes, hurricanes, and other natural disasters as a direct effect of the shrinking numbers of Pirates since the 1800s. Since pirates are indeed in decline for the last 200 years, and since natural disasters are on the rise, they are technically correlated, but that does not imply one causes the other. The same judicious approach has to be applied to the correlation research that I’m trying to do. Although mathematically and scientifically we can’t firmly prove causation between triathlon performance and spending, age, height, weight, etc. if we can accept that there is likely causation as well as correlation, then there may be some benefit to the research.

William, a professor at Iowa State University wrote to point out that although this was a correlation exercise, the values may not be significant.

“Your R2 values are SO LOW that to me they are almost meaningless. I really couldn’t tell you off the top of my head of whether an R2 of 0.05 even means ANYTHING AT ALL! I wouldn’t be surprised, however, if you had enough data, you would find much GREATER correlations by breaking the data down more. For example, you might find different correlations between experience and performance as a function of age. You might find different correlations between performance and height or weight outside certain norms (e.g., outside 135-180 lbs for men) or in different age groups. But the bottom line is that in order to do that, you really need a ton of data to sort through!”

Both Phillip and William are correct in their observation, and it is important to me that if you are going to take the time to fill out this survey, that you understand its limitations. ut Buf you listen back in episode 58, I think I spent a good 3 minutes discussing all the flaws in this survey process. I hope that it never came across as a true scientific study, and that I used the term for what it really is: a survey for which I applied a correlation analysis. The only way we can get the most value out of this is to, as William pointed out, get more samples and break down the data even more to see if we can find greater correlations in more granular data comparisons. To do that, I need your help in getting thousands of surveys back, and you can do that by visiting tri-talk.com and clicking on research. Thanks to the hundreds of you who have taken the 10 minutes to fill that survey out. Please keep them coming!

One thing I did learn from this episode is to avoid the superlatives. “Best episode ever” is something that a producer should never bestow on his own work, and it erodes credibility. Another reason why I am not a professional radio host.

One more comment that came in on the cycling to run faster topic in Episode 57. From long-time listener and two-time guest on Tri Talk, Dr. Bill Thompson of Florida State University wrote:

“I feel obligated to share my disappointment in your shallow comments regarding the book *Run Less Run Faster.* It is not so much your opinion, but the fact that you hadn’t read the book, that puzzles me. We, your listeners and supporters, have come to know you as meticulous and thorough. You are correct in that world class, elite athletes will probably not benefit from this (this being cycling to run faster). But as shocking and painful as it may seem, I don’t think the Kenyans are listening to your podcast!”

If I portrayed the topic of cycling to run faster as a review of the book Run Less, Run Faster, then I apologize. The interest surrounding the book was the reason I wanted to research the topic on my own. It was not intended as a review of the book, but rather an independent look at one of the many reasons how cycling could be used to run faster. Perhaps I should not have even mentioned the book title to avoid the confusion.

Before we get onto the good stuff, I wanted to let you know about a way that you can help raise $100,000 for the Leukemia & Lymphoma Society. At 140miles.com you can not only donate to this important cause, but track the progress of two amazing athletes as they link their Ironman training to raising money for this charity. If you are training for an Ironman, or even thinking of training for an Ironman, why don’t you follow Chris Elmore and David Miller’s training on their website and blog, and compare what they are doing to what you are doing. And, of course, please consider donating to their fight against blood cancer. They have already raised more than $2,000 of their $100,000 goal in just a couple of weeks. That’s 140miles.com.

Let’s get onto the good stuff! I know I billed the compression socks topic as the lead on today’s itinerary, but I’m feeling more like starting with the dimpled water bottle story. You can imagine that I get lots of requests from manufacturers to review and talk about products on Tri Talk. They send me samples, they make claims, their product is the best in the world, on and on. One company notified me of a product they were interested in me talking about on the podcast, specifically a dimpled water bottle that they claimed was more aerodynamic that a standard water bottle. I gave them my standard reply, which was, “thanks, I typically don’t review products unless I know for sure they are a benefit, can you send me any data.” I didn’t hear back for a few weeks, but then one morning I received an e-mail from the company that included data. Not only data, but wind tunnel data on the product from John Cobb himself, possibly the leader in wind tunnel testing for cycling. I’ll give you those numbers in a minute, but first let’s review why dimples could make a difference in a water bottle.

Cylinders and spheres are very convenient and strong shapes when designing bicycle frames and components, but it turns out they are terribly un-aerodynamic. I know they look all smooth and round, how could the air not just flow right on by them? Part of what makes an object aerodynamic is the object’s ability to keep the air attached to the surface as long as possible. As soon as you have what is called flow separation from an object, drag increases. This is why deep rims and disk wheels are more aerodynamic, because the air stays on surface longer, and the flow separation takes place much further along the flow of that object. The same with those thick downtubes that almost all tri bikes have now. More surface area on certain parts of the frame mean less flow separation and improved aerodynamics.

It turns out that with a cylinder or sphere, that flow separation takes place very early as the air travels over the object. But, please dimples on that sphere, like a golf ball, and something changes. Those dimples increase turbulance, which normally you would want to eliminate in aerodynamic design. But this turbulence, or “dirty air” on a sphere has the effect that it actually speeds up the airflow and gives it more forward momentum. As a result, flow separation takes place much later in the flow over the sphere. Even though there is increased turbulence, the trade off is that the increased speeds in airflow has a net benefit on the aerodynamics of the sphere, and the air stays attached to the surface much longer.

It is also important to note this is why we don’t put dimples on just any shape or object for which we are trying to improve aerodynamics. If dimples improve aerodynamics on a ball, why don’t we dimple the wings of an airplane? Or make the bike frame itself dimpled? The reason is that those dimples increase turbulance, and on a wing or aerodynamically tapered bike frame, the flow separation is already fairly good. The net result of increasing turbulence on a shape that already has late flow separation is decreased aerodynamics, while the net aerodynamic result of turbulence on a sphere is positive, because the turbulence contributes towards delayed flow separation.

This is also why there are critics of the dimpled rim of the Zipp 404 wheel. That deep rim already has good flow separation, so why add the dimples and more turbulence? I don’t know, but it is hard to argue with the results of the wind tunnel test of the 404s. It’s possible that the rim is just shallow enough, and the dimples just shallow enough, that the combined result is improved aerodynamics on that wheel.

So, back to this particular product. In theory then, since a cylinder is such a similar shape to a true sphere, the dimples could actually help airflow over a water bottle. And with the typical water bottle much wider than the down tube and seat tube, it certainly sticks out like a sore thumb in the bikes total aerodynamic profile.

The data on this particular water bottle is quite surprising, and I would have been skeptical of it had I not seen John Cobb’s actual comments. He found that over a 40K time trial, the savings from this dimpled water bottle over a standard water bottle was 53 seconds. At a cost of only 19 cents per second saved, that is a very economical aerodynamic purchase, and if it were on the Tri Talk Top 20, the #2 most economical purchase you could make. From the test, most of that savings took place when the water bottle was placed on the downtube, as opposed to the seat tube.

Now, before you get too excited, remember that this was a 53 second savings over a conventional water bottle. The data I did not get was the baseline aerodynamics of the bike without any water bottle. Yes, the dimpled bottle was faster than the standard, but I would guess that it would be slower than no water bottle on the frame at all, depending on the frame, or the bottles mounted behind the seat.

Way back in Tri Talk episode 18, I talked about another water bottle study that John Cobb did, which found that a water bottle mounted on the downtube was in fact actually more aero than no bottle at all, with John Cobb speculating this was due to the air breaking around the down tube before it got to the seat tube. So, you might be saying that this means if a standard water bottle on a frame is good, than the dimpled much be better.

That test that John Cobb did was from 2003. Much has changed since then. It is hard to find a real tri bike now that does not have a true aero seat post. Very few tri seat posts and tubes are cylinders any more. In 2003, when the first tests were done, this was not the case. If your bike is a true tri bike with an aero down tube and seat tube and seat post, I would not place a water bottle on the frame. You are best with the aero drink up front and high mounted water bottles in the back. If it is a standard road bike that you have converted to a tri bike, and the seat and down tube are standard rounded cylinders, then yes, a dimpled water bottle seems to be the way to go. Or, if you are doing an Ironman, and you need lots of fluids with you, you may have to use the water bottles on the frame even on your tri bike, and then these dimples aero bottles would be a good idea.

The company that makes this product is Rocket Science Sports and you can check out their very inexpensive dimpled water bottle at www.rocketsciencesports.com.

And I though I was going to spend just 2 minutes on that topic.

Moving on. You’ll remember that I am now affiliated with Joe Friel’s new company, TrainingBible coaching. I have two exciting announcements regarding the launch of this company. First, TrainingBible.com will be launching their own podcast which will include the current writing and research of Joe Friel. Plus, the podcast will include interviews with the experts from TrainingBible’s coaching staff. But best of all, it will be hosted by me! It’s like putting my voice on Joe Friel’s mind, it’s a thrilling combination. Look for the release of the TrainingBible podcast to release on February 23, just a few days from now.

The second announcement is this: I just came back from Arizona for a seminar with Joe Friel and Adam Zucco, the co-founder of TrainingBible Coaching. Adam was so pumped up about how well the seminar went, that he pulled me aside and said “Hey, David, how can we find a way to get more athletes to try our coaching services?” I said “Let’s give it away free for a month.” In his excitement, Adam said “Great idea! Let’s do it!” So before he changes his mind, right now for the first 50 athletes who sign up, you can get one month of free personal, customized, one-on-one coaching with a TrainingBible coach, and TrainingBible will waive the startup fee. This is 100% free for their Level 1 coaching service for one month. There is no commitment, there is never any contract with TrainingBible coaching, and you can always quit at any time.

Imagine sitting down with a TrainingBible coach and have them review your goals and annual training plan for the year, come up with 4 weeks of customized workouts, with the ability to followup by e-mail. Many of these coaches have been personally trained by Joe Friel with his latest research in training physiology. You have nothing to lose with this offer, and so much to gain. This offer is only for the first 50 athletes, and only for new TrainingBible athletes.

All you have to do is visit Tri-talk.com and click on the free coaching offer and follow the instructions. Or, send me an e-mail to david@tri-talk.com and I will answer any questions you have about the offer, and ensure you that this is in fact a 100% free month of coaching with no continuing obligation.

Speaking of TrainingBible coaching, Joe Friel provided me with some data on behalf of TrainingBible.com for another hot triathlon topic: compression socks. They look cool, they feel pretty cool, and they are relatively inexpensive. But do they really work?

There are 3 proposed advantageous of compression socks. First, improving blood flow back to the heart during exercise. Second, preventing muscles from moving unnecessarily as with excess vibration meaning less fatigue. And third, speeding recovery through that same benefit of increased circulation.

Compression socks have actually been around and used for quite a long time. But they have been primarily used in the medical field for patients with circulatory problems. In fact if you do a Google search for “compression socks”, 90% of the hits will be for the medical use of compression socks. Therefore, almost all of the research has been done on less-then-fit subjects, and almost none of it has been done on actual athletes. Even the data that has been done is contradictory. Two primary studies from 2003 had conflicting results. One showed that the socks did not improve athletic ability, but most patients reported reduced swelling when wearing the socks. But, all of these subjects were suffering from thrombosis, or blood clots, to begin with. The other study from 2003 did show some improvement when wearing compression socks when walking, but the subjects in this test were again, patients, and the maximum speed that they walked as 1.5 miles per hour. Not athletic speed.

In short, there really is no research to support the athletic benefits of compressions socks on athletes, yet.

However, in terms of recovery, there is some good data. From just last year published in the Journal of Vascular Surgery, which I keep on my coffee table right next to Sports Illustrated, there was a study of 14 runners who performed 2 strenuous 10K time trials while wearing the compression socks, and another while not wearing them. 13 of the 14 runners who ran without the socks reported muscle soreness after the run, while only 2 of the 14 reported muscle soreness after the run when wearing the compression socks. That’s pretty good data to support recovery!

However, this same study noted no performance benefit in that 10K time trial. Since this is one of the only compressions sock studies done on athletes, so far the evidence for performance in athletes is neutral. There was no performance improvement when running a 10K with compression socks with these 14 athletes.

But for recovery purposes, almost all the studies support compression socks for recovery.

Here are a couple of other things to consider. Do compressions socks really reduce vibration and therefore muscle fatigue? Many athletes claim that they do, but at least in this 10K study, there was no performance improvement. Also, I question the use of compression socks when performing regular endurance training. If they truly do limit muscle fatigue, are you limiting the amount of soft tissue strengthening by wearing them all the time? In the course of trying to reduce injury by wearing them for every run, are you simply conditioning the muscles to not tolerate race-level vibration and fatigue? Would you do all of your running year round on a cushy treadmill, and never subject your legs to the realities of running on the road? Would you stay on your trainer for every ride and never subject yourself to hills or wind? This argument is not bullet-proof because unlike wind, hills or running surface, you actually can control what you wear on race day. Technically you could train with compression socks 100% of the time race with them 100% of the time. But again, long term the effects to soft tissue strength and tolerance are suspect.

I suspect that the best use of compression socks would be during breakthrough workouts where intensity is high, like racing, and recovery takes longer. But for use during Zone 2-3 endurance running, when you might have 2 days to recover before the next run, that seems excessive. Just like taking supplements, just because a little is good, a lot is not better. Reserving compression sock use for intense workouts and racing, running on a recently recovered injury, or for after your workout during recovery, may give you all the benefits of racing and recovering with compression socks, without the risk of pampering your legs and soft tissue unnecessarily.

I suspect that in the coming months and years there will be much more research on compression clothing and this will have much more clarity. For now, I say get them and try them out. I’m actually wearing a pair of compression tights that I got for $32 at Walgreens in their pharmacy section, far cheaper than the full tights you can get online. But these do look kind of funny when you run. PowerTri.com sells some killer black compression socks for $40 from Skins that look very cool when running. More expensive than the tights from Walgreens, but you look much faster. By the way, I learned a new term when researching this subject. You know that there is aerodynamics, and hydrodynamics, the study of the flow of air and water. There is also hemodynamics, the study of the flow of blood.

That’s all for this episode. If you have not checked out the Tri Talk forums, you are missing out on some fantastic discussion. It’s clean, it’s friendly, it’s current and it’s informational. Have your training question answered on the Tri Talk Forums.

But what is better than the Tri Talk forums? How about a month of free personal coaching from a TrainingBible coach. Go to tri-talk.com and follow the link and instructions on how you can get 1 month of free coaching by a real person at no cost or obligation.

Finally, don’t forget that you can get access to all the old Tri Talk Episodes back to Episode 18. If you have not listened to all 59 episodes, your education is incomplete. Would you only watch Episode 4, 5, and 6 of Star Wars? Would you only read the last 3 books in the Harry Potter series? Of course not! Complete your Tri Talk collection today by visiting tri-talk.com and access all the old episodes. See you next time!

The audio for this podcast can be found here.

The slowtwitch.com article referenced can be found here.

Conjugate sequence training, aerodynamic aerobar positioning, and cycling for a running PR? No kidding! All that, today on Tri Talk.

Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. I want to specifically say hello to listeners from Mason City, Iowa and Columbia, Missouri. In Iowa, I have heard great things about the Mason City Multisport Club, also known as MC-squared. In Missouri, I can’t thank the Columbia Multisport Club enough for their loyal following of Tri Talk, and want to say hello to one of the stars of Columbia Multisport, “Ted Z”. 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 57.

If I had a theme song, I think that would be it. Just like me it is groovy, a little bit cheesy, and made in the ‘70s. That’s cjacks with Rolling in the Hoopty. It is good to back after 6 weeks away from the show. I can’t thank Eric Schwartz enough for covering for me and for doing such an outstanding job for the last 2 episodes. As much as I love my coaching, writing, and training in the world of endurance sports, being away for the last 2 episodes made me realize how much I do love doing this podcast. Mainly, I think, because I love the sound of my own voice.

Today on Tri Talk we have three hardcore, scientific topics to indeed help you swim, bike, or run faster. We’ll lead off the show with a review of data that is from tri-geek heaven. How the position of your aerobars affects your overall aerodynamics and power. Also, have you had enough on periodization over the last 2 months? We’ll that’s too darn bad! Because I have some research on an alternate periodization technique called conjugate sequence periodization. For some athletes, this method of training could be the missing piece to their peak performance. It’s risky, but we’ll take a look at the advantages and disadvantages of this different form of training. Finally, lot’s of talk lately around running less to run faster. I’ll spend a few minutes on some research around why this might work for you.

You can send in your questions or comments to david@tri-talk.com.

Before we get onto the good stuff, I’d like to take a moment and talk to you about two charitable organizations that need your help. Picabo Street’s Ski Challenge and the Sangamon County Child Advocacy Center. Both charities are working for a goal we can all agree on, and that’s combating and easing the pain of child sex abuse. These charities have teamed up with beginnertriathlete.com to form a silent auction on the beginnertriathlete.com forums. If you have triathlon gear sitting in your closet, please donate it to the auction. If you are looking to get a good deal on new and used triathlon gear, with the proceeds going to a good cause, you wont’ want to miss this auction. The auction runs for the month of February on beginnertriathlete.com forums. For more information on how you can donate, please go to the Tri Talk website and click on the link to the auction information, or visit beginnertriathlete.com. The proceeds from this auction will go exclusively to Picabo Street’s Ski Challenge and the Sangamon County Child Advocacy Center.

Let’s get onto the good stuff! Many of you may have already seen this data, but it is worth a prime spot on today’s episode. Slowtwitch.com is probably the coolest site out there for a triathlete. Tri-talk.com is pretty cool too, but if I spend the next 10 years building up my website, I hope that it is 1/10 of what slowtwitch.com is today. Back in November of last year, John Cobb from slowtwitch.com published some data on aerobar positioning and the impact to aerodynamics which included, if not necessarily startling results, at least some very interesting results. All the data listed below is based on a moderate 40K ride at 19.17 miles per hour, or your basic age grouper speed.

For example, completely unrelated to aerobars, they wind tunnel tested the impact of leaving your jersey’s zipper open while riding on the brake hoods. You know those guys who ride with the jersey zipped all the way down? They probably shave their chest just for the occasion? They look cool, but it turns out it is not so fast. You’ll lose 56 seconds over 40K from leaving the zipper down. Yikes! So, it is better for you, and it is better for the rest of us to keep your chest to yourself on the ride.

Now what about aerobar positioning? When I talk about aerobar positioning, I’m referring to the angle of the aerobars in relation to the ground. A flat aerobar position would be the bars close to parallel to the ground. John Cobb took a look at bars high, bars medium and flat, with high having the wrists being just a few inches from the head, and medium being a more reasonable 20 degree angle in relation to the ground.

In these first 3 positions, the elbows pads were placed about thigh width, or fairly wide. What was somewhat surprising was that the fastest times were recorded with the high hand position. That’s right, not flat, but very high. In fact it was 9 seconds faster than the flat position over 40K. It is interesting to note that this article came out in November, but back in September I met with Steve Hed of Hed cycling at Interbike, who spent time trying to convince me that the high aerobar position was in fact the best position for many cyclists. I never included that interview in the podcast, because frankly I didn’t believe him. This wind tunnel test helps support Steve Hed’s theory that the high aerobar position can be faster.

However, there is more. John Cobb also tested aerobar position with the arm rests fairly tight, no longer at thigh width, but bringing in the arms in to a very narrow position. At that point, the fastest position was not the high aerobar, but it was still not he flat position either. At that point the best position was the medium position, this time by a significant 35 seconds over the flat position. That is some serious time savings, getting awfully close to he savings from an aero wheel over a 40K. Note that in both tests, again, the flat position was never the fastest compared to the medium or high.

Does this mean that you should go and move your aerobar positioning to a medium or high position? Not necessarily. First, although the medium aerobar height was the fastest with the narrow arm position, it was the slowest with the wide arm position. If you ride with the elbow pads at thigh length, this test would indicate the medium is not so good. The medium was only the fastest with the narrow arm position.

Second, since we are talking about as much as 35 seconds in aerodynamics, the best aerodynamic position also needs to be weighed against your power output. Your ability to generate power could also be significantly different in each of those aerobar positions. A best-case scenario would be for you to look at your power output for a given HR in each of the 3 positions, even if you had to use the poor-mans power meter setup from episode 54. If you have significant power drop in the medium or high aerobar position, its not worth it.

Finally, comfort. Especially for long-distance racing. If you can’t handle the narrow arm position for more than 90 minutes, just set the arm pads wide. It’s no good to be in aggressive aero position if you keep coming out of the aero position because its not comfortable. The best aero position is one where you are even more comfortable in the aero position than you are on the hoods or drops.

Going back to the power generation from your aerobar position for a moment. I have ridden with my aerobars at medium height for 2 years now. I did it because I found that for speedy time trailing, such as for Olympic distance or less, I can generate more power when my aerobars are up a bit, and not flat. This is because I really grip those bars and use my upper body to generate power, even in the aero position. Now, distance triathlete purists will say, “no, no, David, your hands and biceps need to be relaxed on the aerobars.” Yes, for half and full Ironman racing, I would be worried about energy expenditure. But, for Olympic distance racing, I’m only going to burn 2,000 calories, which I have already stored as glycogen and ready to use. I can afford to be less efficient and more fast. When I grip those bull horns, and really use my upper body to help generate power, it makes a huge difference in my power output. Again, I bring this up because for me, I can generate more power as a result of the medium aerobar position than the flat position. I just can’t engage my upper body as much when the aerobars are flat. By the way, this is also exactly how Tour rider Levi Leipheimer sets his aerobars up when he time trails.

Moving on. I recognize that 3 of the 6 podcasts prior to this episode all already had at least one periodization topic in the episode. Tri Talk has indeed been heavy with periodization topics, but there is no better time to discuss periodization than early in the training season (with all due respect to our great listeners in the southern hemisphere). Plus, periodization is so broad and so deep, that it touches many of the elements we incorporate in our day-to-day training. However, this periodization discussion will be very different from what you may have heard before.

The classic periodization process is also referred to as “linear periodization”. This is due to the staggered but ultimately linear increase in volume over a period of several mesocycles, a single mesocycle typically representing a 4-week block of training for an age-grouper in classic periodization. Again, the concept of classic periodization is to progressively shock the body into an adaptive response that ultimately increases performance on race day.

There is a proposed alternative method to linear periodization called conjugate sequence periodization. This method of periodization follows the same broad look at periodization, which is planning the year around peaking at competitions, separating the training year into periods of microcycles and mesocycles with early gradual increases in volume. But, there is a difference in how those mesocycles are managed. By the way, if you are new to Tri Talk or to periodization definitions, you may want to listen to Episode 52 as a refresher course on the definition of periodization cycles, which might make this next part easier to understand.

In linear and in conjugate sequence periodization, the mesocycle is broken up into 4 distinct microcycles. But unlike linear periodization, where the 4 microcycles are essentially the same with small increases in volume, conjugate sequence uses an almost reverse volume increase technique. Also unlike linear periodization, where the microcycles are all the same duration, let’s say 7 days each, conjugate sequence has varying durations among the 4 microcycles. Before I give you an example of what a conjugate sequence mesocycle would look like, let’s discuss the science behind why it would work.

Conjugate sequence takes advantage of a phenomenon called the Long-Term Delayed Training Effect, or LDTE. LDTE occurs after a period of high training volume, when training volumes return to “normal”. At that time, strength and endurance improve. Although this effect was first observed in weightlifters, two studies in 1992 from the European Journal of Applied Physiology and Medicine and Science in Sport and Exercise both revealed the existence of performance gains from the LDTE in endurance runners and cyclists. LDTE occurs basically after a dramatic drop in volume. Unlike a classic taper, where the volume decreases gradually, LDTE occurs after a fairly immediate drop in volume.

LDTE is unlikely occur in classic periodization, because there is never a long enough drop in volume for the phenomenon to occur. A typical rest week in a 28-day linear periodization mesocycle is about 7 days, and then the athlete returns to the previous volumes. In conjugate periodization, the drop in volume lasts up to 20 days of a 28-day mesocycle cycle, allowing enough time for LDTE to occur.

But, most of those 20 days are not easy days. While taking advantage of the performance improvement from LDTE, the amount of intensity increases in that microcycle far more than would occur in linear periodization.

So let’s look at an example of conjugate periodization mesocycle. In this example, the mesocycle is 28-days, or 4 weeks, similar to a linear periodization mesocycle. The first microcycle of the mesocycle would last 8 days. And those 8 days would be devoted to volume, training at low intensities of 60-80% of your aerobic capacity. This is Zone 2 and very low Zone 3 types of intensities for those 8 days. The second microcycle lasts from 2-5 days, and the focus is speed sills and rejuvenation. This is the time to focus on swim drills, cycling drills, like one-leg drills, and running drills. The volume is cut in half from the previous 8-day microcycle. The purpose is not only to focus on speed-specific drills, but some recovery needs to take place from the accumulated fatigue of the previous cycle to prepare for the upcoming intensity of the next cycle. After the second speed skill microcycle, an intense 5-8 day intensive endurance cycle begins. Again, the volume is half of the volume from the first 8-day endurance microcycle, but the intensity now includes race-specific intermittent or intervals training, or competing in low-priority races. It is critical that during this 3rd intense cycle that recovery is watched carefully, which will be a real challenge. The final microcycle is essentially and easy week focusing completely on active recovery, lasting 4-7 days. The total conjugate sequence mesocycle would therefore last up to 28 days, or 4 weeks.

Just like in linear periodization, these 4-week blocks can be repeated and placed back-to-back, creating a 12-week cycle that can easily be placed into your annual training plan. You should not do more than 3 of these mesocycles for a total of 12 weeks.

OK, now that we have defined conjugate sequence, and how it could increase your performance through taking advantage of the Long-Term Delayed Training Effect, should you really use this?

This is a risky training alternative. It is risky because it is rarely used, and therefore it is tough to gauge how well it really works. It is primarily risky because of those 5-8 days of significant intensity. Injury red flags are flashing all over the place.

So who should consider conjugate sequence periodization? I would only recommend this training technique under a few conditions.

First, only for advanced athletes with several years of training and racing. These athletes know their bodies, know how to listen to their bodies, and are better in tuned to how this change will effect them. Second, only athletes without a history of injury from intensity. Some athletes are more injury prone from volume, but some are more susceptible to injury from intensity. The density of the intensity used in conjugate sequence is significant. Third, only after you have spent several months developing a solid aerobic base in the season. Going straight into conjugate sequence at the beginning of the year introduces many risks. It is best reserved for the Base 3 or Build mesocycles. Fourth, only if as an advanced athlete, you have found that after using the classic linear periodization for a few years, you feel that you have maxed out and are burned out with the same training routine, and just aren’t getting any faster. Some athletes simply respond better to higher intensities, and you’ll never know if you don’t try.

If you found yourself getting lost in this topic, you can read everything I just said at tri-talk.com, where all the recent Tri Talk episodes have transcripts on the Tri Talk blog.

I have to thank Joe Friel who provided me with the data behind conjugate sequence periodization. This is the kind of information that the coaches from TrainingBible Coaching have access to. If you are interested in becoming a TrainingBible Coach, or would like to be coached by a TrainingBible coach, send me an e-mail or visit TrainingBible.com.

Can I also just tell you that I accidentally referred to conjugate sequence as “conjugal sequence” about 50 times when I tried to record this topic. I can’t tell you how many takes of this section I had to do as a result. This is why I am not ready for prime time radio. For those of you who don’t know why conjugal sequence is funny, then bless your heart and your beautiful clean mind.

Let’s wrap things up. I’d like to spend a few minutes on a topic that has generated quite a bit of buzz lately. There is a book out from Runner’s World called Run Less, Run Faster. I have not read this book, but I love the concept. The idea is to train at only 3 runs per week, with the other 2 workouts being a quality cross-training workout. Is it just me, or have we triathltes known this for years. I should have written this book first. I can’t tell you how many times I have seen this take place, where a triathlete is only running 3 days a week, and still makes a marathon PR because he was training for a triathlon at the same time. In fact, the free on-line running plans out on Runner’s World have gone as far as reducing the runs from 5 to 3 in their plans, with 2 days of cross training. I totally believe in this concept.

Having not read the book yet, I thought I would do a little research of my own into why this would work. There are probably a ton of reasons. Injury prevention, recovery, mental variety to name a few. But, I found at least one link between cycling training and a reason behind how that could help you on the run.

A 1996 study in the International Journal of Sports Medicine took 204 well-trained cyclists and runners and measured the size of their hearts. The size of cyclists hearts was overwhelmingly larger than that of the runners. It is probably because you can cycle for much longer than you can run, thus spending more time in a highly aerobic state. OK, you say, that’s nice. But so what? When you combine that with a second study published in the American Journal of Cardiology which took a look at the correlation between heart size and VO2max, then things get interesting.

There are many variables that determine your VO2max, unfortunately most of it is genetics. But, this second study I just mentioned found a high correlation between heart size and VO2max. In the fact the mathematical correlation was r=.80. A quick review on the how the correlation expression works: All correlation is measured between –1 and +1, with –1 begin a negative correlation, +1 being a positive correlation, and 0 being no correlation at all. A r=.80 correlation is considered a very high correlation, and would be sufficient enough to conclude that large heart size is linked to a high VO2max.

So to bring this topic back full circle. Theoretically, if you were to spend some serious time cycling, probably years of cycling, this could change your heart size, and therefore increase your VO2max and subsequently your run times improve. Lance Armstrong’s first marathon, which he completed in under 3 hours, is a pretty notable example of how cycling cardiovascular endurance can translate into other sports.

There are a few problems with this argument. First, there are lots of ways to increase your VO2max other than increasing your heart size. You could invest just as much time in interval run training and get the same results. Second, it goes against the principle of specificity, which says that you will always perform best when spending the most time training in your specific sport. The truth is that Olympic runners spend 95% of their aerobic workouts just running. This Run Less Run Faster concept has not been proven beyond the age-grouper or even lower-level elite athlete. I think this does work well for new runners, but for runners who are looking to squeeze out that last 15 seconds of speed off of their 32-minute 10K, you don’t need to bike, you just need to run.

But again, for us mortals, I think that this concept has huge potential for application, and is worth incorporating into your next running plan. Even if not for the potential in increased VO2max, which might take years, as mentioned, the injury prevention, recovery, mental variety in your training might make it all worth it.

That’s all for this episode, I’ll be back at the end of January for Episode 58. You know, I spent time today telling you about slowtwitch.com and beginertri.com, but you know what, Tri-Talk.com is a pretty darn cool website too! Come check out the Tri Talk Forums and get your individual triathlon question answered today.

A quick hello to the rest of the TrainingBible coaching team! I hope to see you next month at our TrainingBible Coaches Meeting in Arizona! See you next time!