What beautiful curves! (1/2)

To me Ironman training is a huge learning curve (pun intended) of figuring lots of different elements out, getting better at them, and hopefully becoming faster as a result. I have been doing this sport for about three years now, and every so often I come across a new concept, technique, or approach that changes how I think about triathlon. A great source of this learning has been my coach Alan Couzens, who is very very knowledgeable on training Ironman and even Ultraman athletes.

Alan just posted a great piece on fatigue curves (actually two pieces: here is the first article, here a second follow-up article) - the relationship between our performance over short and long durations. I found this very inspiring and decided to look at Alain's and my fatigue curves in search of some answers. But some background first:


When we go out and train, we produce a lot of data on how fast we are going, what kind of power we produce doing it (watts on the bike), and how hard it is for us to do (our heart rate, to some extent). When you use a power meter on the bike you can do performance tests pretty easily yourself: go and find a flat and quiet piece of road, go as hard as you can for a prescribed period of time, and record how many watts you produce over that period of time. Put it in relation to your weight and - presto - you know how well you are doing.

The tests that we usually do are 5 minute and 20 minute tests: go all out and see what you produce. Over the last two years I have done them a good number of times, and I can honestly say they hurt a lot :-). The 5 minute test is closest to a VO2max test, and a 20 minute test is somewhere between a VO2max test and a threshold test. VO2max is the maximum amount of oxygen you can take up, which is something akin to "the size of your engine", and the threshold is usually taken as the power you can maintain for an hour, and is roughly the level where you start producing more and more lactic acid.

Over time I have seen my 5 minute and 20 minute power go up and up, until it plateaued in the last year. At my best I have put out 495 watts for 5 minutes, and 425 watts for 20minutes, or about 5.82 w/kg over 5 minutes or 5.00 w/kg over 20 minutes. There are tables from which you can tell how you stack up - apparently 5 minute power of 5.82w/kg is in the range for a "Category 1" racer in cycling - whatever that may mean. By looking at the two different numbers you can understand better where your qualities lie. In our testing we never looked beyond the 5 and 20 minute test to date, and this is where fatigue curves come in. More about this in another post.