At a glance
Alan Couzens, MS (Sports Science)
Last time we took a look at the concept of the “fatigue curve” or power-duration curve. I outlined how different athletes will have different ‘drop off’ rates in their power as the duration of the test or event increases. Some will have very strong short power and drop off a lot as endurance becomes more of a factor. Others will have the opposite profile. While there is certainly an element of genetics that comes into play in determining an athlete’s profile, there is also a level of malleability. In this article, I’ll offer some advice on addressing weaknesses & molding and shaping your fatigue curve to better match the demands of your event.
In the last article, I provided an example of a ‘natural’ power athlete with a fatigue curve of 12.5%. Shown again below…
While this athlete would do very well in events shorter than 5min duration, he is ill-prepared for the demands of Ironman and at the power numbers given & average weight would likely find himself in the “back of the pack”. Assuming that this power athlete has competitive endurance goals, how can we go about shaping his fatigue curve to fall more in line with that of a competitive Ironman athlete?
2 specific strategies will shift the fatigue curve more towards the endurance end….
- More volume
- Specific preparation at or below the ‘functional threshold’ (1hr power).
1. More volume (General Preparation)
As an athlete accumulates more and more training over time, they will tend to become naturally better endurance athletes. This is exemplified in the progressive “distancing up” of track athletes over the course of their careers. More volume will naturally take away from power and give to endurance. This is an important consideration for athletes whose event demands power, e.g. track cyclists, pool swimmers, middle distance runners. It is certainly possible for these athletes to over-do the volume to the extent that it negatively affects the specific performance of their event. This is less the case for an Ironman athlete. However, even for these athletes the response to volume will only take them so far and when it is maxed out, a periodic reduction in volume coupled with a greater emphasis on specific preparation for the event can actually enhance endurance performance, which brings us to point 2….
2. Specific preparation at or below the functional threshold
If we look at a typical power-duration curve like the one shown above, general volume will tend to exert a very broad upward force to the right side of the curve, i.e. volume will tend to lift the whole curve up & cause it to ‘pivot’ a little around the 60min duration point – taking a little bit away from the top end and giving it to the bottom end of the curve. However, it’s also possible to a small extent to move a given point a little away from the curve. This is the essence of specific preparation for a given event. Lots of work at slightly above the athletes ‘best 10hr’ intensity will lift their 10hr point slightly above the trend of the curve. Lots of work at the 2hr intensity will do the same for that point of the curve, i.e. without having too much effect on the broad nature of the power duration curve, the athlete can lift given points on the curve with a specific focus on that intensity for a period of time.
So, what constitutes ‘lots of’ specific work? This is obviously dependent on where on the curve your weakness lies. An athlete with a threshold weakness clearly can’t expect to do the same absolute amount of specific remedial work as an athlete with a weakness at Ironman intensity! Here are some practical guidelines on the max amount of specific intensity work (% of total time within your week) born from experience…
|Intensity||Maximum share of weekly volume (%)|
|5 to 10 hour power||30%|
|2 to 5 hour power||15%|
|1 to 2 hour power||10%|
|10 to 60 minute power||8%|
|1 to 10 minute power||5%|
“This sounds great!” I hear you saying. I don’t care about the entirety of my curve, I’m signed up for x,y,z and I want to maximize my performance for that one event (at that one point on the curve) so I’m going to direct as much training as possible towards that point. There are 2 issues with this emphasis on specific preparation…
- Most athletes will have to decrease or (best case) maintain general volume when raising the intensity at a specific point on the curve. This can be a bad deal for endurance athletes as rule 1 is – general endurance will always be improved with more volume.
- The ability to swing a point away from the curve is limited. Fundamentally, you can’t escape your curve. While you may be able to gain a % point or 2, you’re not going to find yourself with the 10hr number of a 5% curve and the rest of your points sitting on a 10% curve. For this reason, any forays away from general preparation should be short, well spaced & directed towards an important event. Your greatest attention should always be paid to lifting the curve as a whole, i.e. general endurance/strength.
In the next article, we’ll step away from training theory for a bit and get down to the nuts and bolts of looking at training and racing files. Your power meter is able to generate a mind frazzling amount of data. I’ll offer my thoughts on which numbers are the important ones.