I spent Saturday 19th March 2011 in Carlisle on a UKAthletics Endurance day, tutor Stephen Pearson from Horwich RMI.
We covered a pretty wide range of topics. The one that I found most thought provoking was the idea that you should link all training sessions to one of the three energy systems.
The simple way of viewing energy systems gives these three types:
- ATP/CTP – which uses CTP that is already stored in the muscle and lasts up to 7/8 secs
- Anaerobic Glycolysis – which uses stored glycogen to produce energy without requiring Oxygen and lasts up to around 120 secs
- Aerobic – which uses oxygen and carbohydrate to produce energy which lasts indefinitely
The simplest model implies that you use these one after another until they are fully depleted. It is then possible to “refill” these whilst still exercising.
On the way home we discussed how these might be used in a typical fell race and immediately got into difficulties. At the start of the race, do you completely use up the stored ATP before switching to the anaerobic energy then to the aerobic energy? Do you use a little bit of the ATP/CTP energy and a bit of the anaerobic system but mainly the Aerobic system? What happens if you push hard up a hill, are you using more anaerobic energy and then have to slow down if this runs out?
Is it the case that there is a limited amount of energy available in the muscle that has to be kept topped up by the various energy systems, and that fatigue happens when the systems cannot cope with demand? If so, why is it possible to run ultra-marathons?
This model seemed too simple for me, so I started researching. The article I discovered almost immediately was this one by Professor Tim Noakes on “Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance.” This article goes into much more depth than I had discovered before and makes some very interesting points.
I will come back to this when I have had a chance to read and digest the paper.