Lionel Sanders' and Josh Amberger's Bike Splits and Power Comparison

Comparing Josh Amberger and Lionel Sanders Bike Splits at Ironman Hawaii 2018.

I recently received an interesting question from one of our athletes that is worth sharing:



Lionel Sanders was 2min faster than Josh Amberger (at the Ironman World Champs), but held 62watts more power over the 4 hours and 20 minutes ride. Why such a big discrepancy in power? Google has their weights listed as Lionel being 11 lbs  more. Would 11 lbs require 60+ more watts? Damn.

Josh Amberger 4:18:43
250 Normalized Power
235 Avg Power
25.9 Avg MPH
Lionel Sanders 4:16:59
308 Normalized Power
297 Avg Power
26.2 Avg MPH



Good information, and yes 60w seems like a big difference for only .3mph gain in speed. A couple thoughts. 

- First off, I believe Josh on his Felt IA is in a more naturally aerodynamic position than Lionel. It's worth googling pics of Josh and Lionel and seeing the difference. This isn't to say that Lionel has a "bad" bike fit. I fully expect it is near the best position his body can have on a bike. It's more an acknowledgment that some people can fold themselves into a more natural aerodynamic position than others. 


- The Felt IA is consistently one of the most aerodynamic bikes money can buy in *all wind conditions* (many bikes are only tested aerodynamically in a headwind, which is not what Kona typically delivers). Maybe that is worth 5-10 watts.


- Josh is listed as 5'7'' tall. He is also not a particularly broad-shouldered athlete. Lionel is 5'10'' tall, with more muscle up top. Surface area has a lot to do with aerodynamics, and in particular you want to keep the leading edge of "your personal vessel" as narrow and small as possible. Broad shoulders, muscle, etc all creates more drag. Maybe this is worth another 10-15 watts.


- Like you said, Josh is 10-15lbs lighter than Lionel, which could be worth a few more watts.


- But most importantly, Josh was in the lead bike group, and Lionel had to mostly bike alone the entire day. From the data I've been able to collect over the years, being in the lead group is worth about 10% power savings. For example, local stud Guy Crawford is a few inches taller than Lionel, and weighs only a few pounds more. At the 70.3 World Champs last year, Lionel and Guy had almost the exact same bike split, but Guy was in the lead group, and Lionel rode solo a few minutes back. Guy held ~320-330 watts for the 56miles, and Lionel posted his power in his typical 70.3 power range of 350-360 for the same race. About 10% difference between the two athletes. My conclusion is that missing the main swim group probably cost Lionel 20-30 watts of "legal drafting" benefit at this event.


So tallying all this up, and I could see on the high side Lionel loosing maybe 70watts, and the low side 40watts. So 55-60w makes sense. 
Not much Lionel can do about body weight and height. I'm sure he has spent a fair amount of time in the wind tunnel, hopefully maximizing his position on his current bike. I suspect any aerodynamic penalty he has is more from his morphology, and less from the Garneau Genix (he has a natural "A-Back" profile, which means his back pops up in the middle. Lance Armstrong has a similar back profile). 
So really, his best bet to ride faster is to swim faster. This is ironic in a way, but the time savings from being in the group would be huge. If he swam near the lead group, sat in a bit on the bike until late in the day (maybe at mile 80 start to lay on the hurt he is so famous for), then run to his normal world-class ability, he would probably put together his best possible result on the day. And historically I think this is what has worked best for him... like last year. He had a relatively good swim, broke away the 2nd half of the ride, and ran pretty well. Lost by .5%. Not bad. 
To further complicate this: at less competitive races swimming fast may be less important. There are less "super swim/bikers" at a less competitive event. So if an athlete swims like a fish at one of these events and gets out in the front of the race right away, it is less beneficial because he/she may have nobody around to ride with. It makes sense why many athletes say, "swimming faster isn't worth the time and energy it takes to shave only X seconds or X minutes....". And I would agree this holds true, until everyone in the field is swimming faster except for you! 
And will all that said, I'll conclude by mentioning that Bart Aernouts swam slower than Lionel (by a few seconds) and still took 2nd overall in world record time. Bart had a brilliant ride and run compared to 2017. Which just goes to say that some days you have good legs, other days you don't. :-) 
Interesting stuff to talk about, and thanks for the question. 


  1. Will Josephson Will Josephson

    Interesting analysis to read over coffee before training. I like your terminology in own personal vessel.

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