Tuesday, September 18, 2012

A Look At Power Files...

Last week I saw a Training Peaks blog post by Joe Friel about Jordan Rapp's bike split at IM NYC. If you're into riding with power it's well worth the read. Of course, Jordan is a pro so as age groupers we don't necessarily want to try to copy exactly the way he rides, but there are some good lessons there for sure! Anyway, here's a graph looking at his power distribution throughout the race. the thing to note here is how (for the most part) it is really steady- no big spikes but no big lulls. It appears to be going down in the latter half of the ride but also note that the course is an overall down in the second half and if you ride with power you know that you can still go pretty darn fast without having to produce the same power on a downhill so that easily explains the slight downward slope you see.

The purpose of this post is just to point out something I see very commonly from power files from some of my athletes... and it's something we work on correcting over time... notice this file below. I've eliminated everything except power (pink) and the elevation profile. I look at this and see immediately that this athlete is wasting a lot of energy with power spikes and lulls... there's a lot of coasting going on here (as noted each time the power line drops to zero) followed by big spikes which is costly in terms of energy output. Ok if you're a cyclist training for cycling races and you need to be trained to go from zero to sixty in short order to cover a break or something, but the name of the game in triathlon is to ride as fast as you can while conserving as much energy as you can and a ride like this one is not meeting that purpose.

Contrast that with this file below. See how nice and steady this is? NO big spikes, very little coasting, steady throughout the 4 hours. Even on the climbs you don't see big spikes at all. Beautiful! This is great race day specific training. Fwiw, this athlete is going to Kona and it's not confusing as to why he is capable of running well after a bike ride like this- he has taught himself to ride with very steady effort, so he can ride quickly while simultaneously not wasting excess energy.

So if you have a power meter, look at your files and note how many spikes and lulls you see... and over time, on your long/specific steady state rides, try to make your pink line look a little more like the one you see above. Even if you don't have a power meter, you can still focus on keeping steady pressure on your pedals while you train... try to avoid coasting whenever possible, and avoid the feeling of spiking effort on every little uphill. You'll save yourself a lot of energy!

And in case you're curious, here's a graph of my ride today. Obviously the goal of every ride is not simply to ride steady steady steady... Can you guess what workout my new coach told me to do? ;)


Katie said...

Thanks for sharing and definitely makes me interested to see what my ride files look like. I'm afraid they look more like exhibit a on how not to ride :)

Libby said...

such a great point. love it and can't wait to read that article. 100% agree, this is something I've worked on big time over the years that has helped me out enormously in my ability to run off the bike and my ability to stay patient and smart on the bike. who's the new coach?! do tell!