Threshold Part 4 - Other Models

In Part 3's exploration of mathematical thresholds we were looking at methods of approximating a rider's power curve, which allows us to estimate maximal power for a given duration. However, that's rarely how we ride (or run, except on the flattest courses). The models discussed assume that an athlete stays at precisely the same power for the duration of their effort, but in the real world only TTers even come close. So this post will look at ways of dealing with variation.

Threshold Part 3 - Mathematical Thresholds

So far I've looked at the biochemistry behind thresholds, and evidence for whether thresholds exist (it appears they do, but not the one we all call 'threshold'!). For this post I'm going to look at some of the ways that we have tried to describe our thresholds and limits.

Threshold Part 2 - What is a threshold?

In this post I will look at some of the common 'thresholds' and empirical evidence for their existence. I'll be using evidence from the world of running - as a sport it is perfect for the purpose; we are well-adapted to it as a species over a wide range of distances (read 'Born to Run'), and we have kept records of the limits of our achievements. Whilst they were not all run by one person, they form a lovely natural experiment into the limits of human physiology.

Threshold Part 1 - Introduction & Energy Systems

'Threshold' is a word you can't avoid in endurance sport. But what does it mean? And how do newer views of exercise physiology improve our understanding of where our barriers lie?

Most serious endurance athletes will have an idea of where their 'threshold' lies - whether FTP for cyclists, HM pace for runners, CSS for swimmers. The usual understanding is that above 'threshold', exercise is associated with a gradual rise in the evil lactic acid, which eventually causes the athlete to have to stop. Below threshold, lactate stays steady. Some models appear to allow the athlete to go on forever, but others suggest (and the real world demonstrates) that exhaustion still occurs, and the athlete must stop for what is presumably an entirely different reason.

I had this planned as one post, then two, then more - I'm not sure now, but I think breaking it up into bits is going to help avoid head-spinning.

I'll start with a quick review of energy systems: