Testing the effectiveness of elliptical chain rings, and can an ice slurry improve performance in the heat? Answers to both of those subjects!
Welcome to Tri Talk your podcast source for triathlon tips, training, news and more. I’d like to wish the participants at the upcoming Ironman Regensburg a great race, and I’ll be watching you in person from the sidelines in Germany this week-end. 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 71.
Today on Tri Talk I am looking forward to sharing the results of my tests with elliptical chain rings. These are a fascinating cycling component used by many triathletes and a relatively inexpensive upgrade. But do they work? We’ll also look at the effects of ingesting an ice slurry prior to exercise in the heat, and if this can help improve performance. I recently discussed this same topic briefly in another public presentation, and I am sorry to say I gave the wrong information to that group, and look forward to correcting my mistake.
Let’s get onto the good stuff! Many of you may know all about elliptical chain rings, but let’s do a quick review. The motive behind elliptical chain rings is to reduce the dead stroke at the top and bottom of your pedal stroke. These are the points at which a typical cyclist is getting the least amount of power in the stroke cycle. Elliptical chain rings do two things: First, they accelerate the stroke in the dead spots, and second, they maximize power when the crank is at about 15-20% below the horizontal position into the downstroke. The actual terminology is that they reduce the effective gear ratio when passing through the dead spots and increase the effective gear ratio when going through the power phase of the stroke.
The current scientific support for elliptical rings comes from one preliminary report done by the University of Valladolid in Spain. This test took 8 elite cyclists and had them perform 3 sets of tests on regular rings, and elliptical rings. The first test was a standard progressive incremental test to exhaustion. Basically warm-up, then increase the wattage load by 10 watts every minute until exhaustion. The second was a series of sprints, and the third was 90% of their max wattage for as long as they could maintain, or up to 25 minutes, whichever came first. Very similar to a triathlon sprint-distance time trial.
The results were encouraging. A 3% improvement in wattage in the incremental load test with elliptical rings over standard rings. That’s nothing to sneeze at. That would be about 43 second faster over a 40K time trial for a typical age group cyclist. Considering that elliptical rings go for about $250, that could be a very good investment for 42 seconds. Much less than the 45-60 seconds saved from a pair of aero wheels at 10 times that cost.
The problem with this report is that it is not a peer-reviewed study. In reading the full report, the methods used were outstanding, all the standard lab protocols and processes were followed. It was a professional research job. It just never got out of the University for wider publication. In fact, the publication itself lists several problems with the report, including:
“Obviously, for a bigger group of test subjects and with control of parameters considered as optimal, it would be necessary to do a statistical analysis of the results, so they could be properly published in a scientific publication.”
“Even so, tests carried out using this trainer, as would happen with any other model or make, cannot guarantee that the results attained would be valid for real world cycling on the road.”
Unfortunately, there have been other studies that have been published in the community that show no improvement with elliptical rings, including one published in 1992 in the American College of Sports Medicine that reviewed four different chainring designs: round, the old Shimano Biopace, and two engineered ellipse designs. There was no detrimental performance with the elliptical design, just no difference between elliptical and round.
This was repeated in a study published in 2003 in the Journal of Applied Physiology. No difference between elliptical and round rings.
Proponents of elliptical rings will argue that modern rings offer the advantage of an variable positioning system, meaning you can choose the position of the ellipse and customize the angle at which the maximum power is applied to the cranks. These earlier studies did not use variable elliptical positioning, and so the results were inaccurate. Proponents will also argue that there are plenty of pros who use the system, and have done quite well with them.
It would be great if we could find a peer reviewed study with the modern variable system. Unfortunately, all we have on one side currently is a preliminary report from a respected university in Spain, which report never made it to publication but including the variable ellipse system, vs. published studies that show no benefit but without the variable system. Really, we don’t know for sure.
This is where my tests come in. I’m going to split my personal tests of the elliptical system into two parts, a story, and real test.
I bough some elliptical chainrings in the fall to go with my new custom-built SCOTT Plasma. I love that bike.
I began riding my new bike at the beginning of my training season in October. When performing time trials, I immediately noticed that my power was down significantly. I attributed that to the fact that I had just finished several weeks of very easy training, and my fitness was definitely going to be less this early in the training season.
6 months later, I was still doing time trials at 10 watts lower than what I had been doing the previous season at the same time of year. I knew something was wrong. My training routing was identical to the previous year, I was using the same power meter, I was performing the time trial in identical environmental conditions in my climate-controlled basement. The only thing different was my new SCOTT plasma.
Fortunately, I still had my old Cervelo. I began to do workouts where I would switch between bikes down in my basement. 30 minutes on the Cervelo, and 30 minutes on the Plasma, maintaining the same HR for those durations. I then did intervals maintaining a specific HR again, and switching between the Cervelo and Plasma during the rest period between intervals. I did blocks of Zone 3 work, blocks of Zone 2 work, back-to-back and switching bikes.
The results were unmistakable. I was consistently 10-15 watts lower on the new bike. You can imagine that this was devastating to me, I just spent thousands of dollars on this new bike, and I was generating less power from it.
I was sure it had to be the fit. I took days measuring and re-measuring, fitting myself again to the bike. I actually developed a new fit process from this experience, where I took two pictures from the side on each bike where I would be in identical cycling positions, and then super-imposed those images over each other to see where the differences were. I got to the point where the fits were so identical, that I could superimpose the two images and you couldn’t tell that there were two different riders. The two pictures of me on the two different bikes were identical.
I duplicated the tests over a period of two weeks with no change. The new bike was 10-15 watts slower.
At this point, I am confident it has to be the elliptical rings. I then perform a third round of tests over a 2 weeks period experimenting with different variable positions. I got the same result.
Finally, I put normal round rings back on the SCOTT Plasma. The results were immediate. Identical power output for the two bikes.
I felt that this was still not enough, and enlisted the help of Jameson King, an elite triathlete who had also just added elliptical rings to his new SCOTT Plasma. With Jameson, I did a more formal test.
Jameson and I did the following test:
– 20-minute warmup on Computrainer, calibrated computrainer
– Four 15-minute rides maintaining a 120 HR at elliptical position #5, #4, #3 and regular circular rings
– Power and speed were blinded to Jameson, he could only see cadence and HR
– Took the average power for the final 7 minutes of all 4 tests
1. Position #5 135 watts 120 average HR for final 7 minutes of 15-minute ride
2. Position #4 140 watts 120 average HR for final 7 minutes of 15-minute ride
3. Position #3 142 watts 120 average HR for final 7 minutes of 15-minute ride
4. Regular rings 147 watts 120 average HR for final 7 minutes of 15-minute ride
As you can see, his results were almost identical to mine: a 12-watt difference between position #5 and regular rings.
I recognize several potential flaws with the test, such as:
– Cardiac drift. Unlikely, as we would have seen HR drift up for a given power output instead of HR staying level over the hour test, Jameson is a fairly fit athlete and an hour in low Zone 2 would not cause him to become fatigued. In addition, when I did my multiple tests, I specifically rotated starting out with elliptical rings first vs. Regular first for each round of testing.
– Computrainer calibration. Possible. However during our testing with Jameson, the bike never left the trainer. We simply swapped rings and positions in between tests. I deliberately took the last 7 minutes of the 15 minutes test to ensure the computrainer was warmed up again between tests.
– Did not test position #2 and #1. I regret not doing that, but at the time we considered it unnecessary due to the fact hat both of us are riding in a typical forward triathlon position, with an effective seat angle of about 80%.
– Incompatibly between bike fit and elliptical rings. Also possible. It could be that the fit that Jameson and I have is not compatible with elliptical rings.
Now, you may have noticed that I specifically did not mention a brand name of elliptical chainrings. I recognize that this is a somewhat ridiculous measure, as there is only one legitimate manufacturer of elliptical rings, and I’m sure you know exactly which company I’m talking about. However, I sent these results to that company, and have not received a reply. I’m hoping this podcast might change that lack of response, and I wanted to give the manufacturer the opportunity to respond before I start being that explicit with the brand name.
So what do I recommend? I don’t recommend not getting the rings. I don’t recommend getting them, but I don’t recommend not getting them either. If you do get them, or if you already have them, here is the critical part. Test them. Don’t take it on faith from the manufacturer, don’t take the word of a few pros, don’t take my word for it. Do your own test. Even if you don’t have a power meter, you can use the poor man’s power meter from episode 54 and I think you would be able to effectively do this test.
Moving on. I have bad news, and good news. The bad news is, I’m not taking on any more athletes at this time. The good news is that there is still a way that you can I can work together. Joe Friel and I have created Sprint and Olympic intermediate plans that include limited coaching with the plan. For a fraction of the cost of a dedicated coach, you’ll get your own daily, detailed training schedule, and 2 phone calls with me to review your plan or talk about anything else you want to talk about. Just go to TrainingPeaks.com, click on Plans, Joe Friel’s plans, and in his Sprint and Olympic plans, you’ll find the plans that we have co-authored, complete with coaching.
Let’s talk about an ice slurry. I need begin with an apology to a group of athletes I was presenting to 2 weeks ago on heat acclimation. During the Q&A section of that presentation, the subject of an ice slurry came up. I had just that morning read the abstract of a study on ice slurry ingestion, and answered the question without really knowing the answer. In fact, I answered it completely wrong, based on that 15-second glance at the abstract. So, I apologize to the several hundred of you who heard that answer incorrectly, and this next section corrects and supercedes my previous answer.
Now, the question is: can taking in an ice slurry improve performance in the heat? Would it really make a difference compared to plain cold water? From Medicine & Science in Sports & Exercise, 10 males ingested 7.5 grams per kilogram of either ice slurry or cold water before running to exhaustion at ventilatory threshold (low Zone 4) in a hot environment. That would be 40oz or 1.2 liters of fluid for a 150 pound athlete. The hot environment was pretty hot, 34C or 94F.
The results were notable. The athletes ran 10 minutes longer to exhaustion with the ice slurry. The athletes had their rectal temperature taken before and immediately the run. Yes, rectal temperature. All I can say to those 10 male subjects is: gentlemen, in the name of science, I salute you. The temperature dropped by 0.66°C after the ice slurry ingestion compared with 0.25°C with the cold water. So their temperature was significantly lower even before the running began with the ice slurry. However, after the run, the rectal temperature was actually higher. In other words, the ice slurry let them run longer and get to a higher rectal temperature.
It is also very interesting to note that there was no difference in HR nor sweat rate between the cold water and ice slurry.
OK, how can we apply this to racing. For IM athletes, this could be a very effective part of your nutrition strategy. I don’t know that I’d take it in before the swim, but taking in an ice slurry on the bike is possible. The practicality of taking it in on the run is tough. It would be very difficult for your ice slurry to stay an ice slurry after 2.5-7 hours on the bike for a 70.3 or full IM. I think you could still have an ice slurry as you came out of the swim, and even on your bike for the first couple of hours.
For Sprint and Olympic racing, getting in an ice slurry just before the run becomes more and more possible. I don’t know how much it would help for a Sprint, but for an Olympic event in the heat, it could be helpful. For example, in this study the time to exhaustion at Zone 4 was 50 minutes vs. 40 minutes with cold water, and that is about how long an Olympic-distance age-grouper will run for his 10k. However, how often is it 93 degrees for the run portion of an Olympic-distance race that starts at 7am?
It appears that even if you can’t get a real ice slurry, getting your water as cold as possible for the duration of your race would also appear to help in the heat. This study did show that even cold water lowered temperature, but it would have been great to have them use 3 tests: room temperature, cold water, and ice slurry, and see if the cold water was significantly better than warm water.
I want to thank my editor over at Rocky Mountain Running Magazine, Aaron Lovell, for sending this study to me.
I promised Carolyn Doll, one of our local USAT officials, that I would ask my fellow triathletes to tape the safety certification sticker on the inside of their helmet to ensure that it does not fall out. USAT officials have been asked to really crack down on helmets, and many helmets currently in use have not been approved by the US Consumer Products Safety Commission, or equivalent international safety certification. That is a DQ penalty, and if the referee has reason to suspect that your helmet is not CPSC certified, and you don’t have the sticker to prove it, you risk a DQ. I recognize that many of you are not in the US, but if you race in the US, this still applies to you.
That’s all for episode 71, I’ll be back in a month, really, discussing among other things, the theory of the staggered taper. I’ll see you next time.
The following was never published in audio format. Sund to the tune of The Surrey With the Fringe On Top from the muscial Oklahoma!
All my competition will scurry
When I take my race-day ice slurry
When I take my race-day ice slurry with the foam on top
See my core temperature it decreases
In this heat I won’t fall to pieces
That’s because the heat it releases from right out my top
I’ll spend less time in the blazing sun
My skin won’t turn to leather
My temperature stays low for the run
In case there’s a change in the weather
Metro-Goldwyn-Mayer please don’t sue me
It will never make it to a jury
Intellectual property is blurry and the suit would stop
When I sing about my slurry with the ice on the top