Thursday, April 24, 2008


Vern Gambetta recently had a good post on his blog. It was short so I'll reproduce it fully here:

Everything is connected. Impossible to isolate one system of the body, when one is working then all are working. You may designate a workout as having a metabolic emphasis or a neural emphasis, but there will be profound effects on all systems of the body not just the “targeted” system. I particularly enjoy swim coaches who have all these neat color coded charts with workouts in very specific heart rate zones designed to target specific energy systems – the body is so much smarter than that, it is always seeking to adapt and preserve homeostasis. It is IMPOSSIBLE to isolate one energy system or for that matter one system of the body whether it is neural, cardio vascular, muscular, or endocrine hormonal. Recognize that there is always a spillover effect, for example 3 x 150 meter sprints at 95% with full recovery will maximally tax all systems of the body. You will be working at greater than VO2 max during a portion of that sprint. Understanding this has great implications, as a coach it took me too long to figure this out. You will find if you grasp the idea that you will need to do less “fitness” oriented training when you realize the cumulative effect of all the components of training.

I was reminded of this by a study that popped up the other day:

The relative contributions of anaerobic and aerobic energy supply during track 100-, 400- and 800-m performance.

AIM: The present study set out to identify the relative contribution of the laboratory determined physiological measures, (maximal) accumulated oxygen deficit (AOD) and maximal oxygen uptake (VO(2max)), when predicting track performance.
METHODS: Fourteen volunteers (men: n=10; women: n=4); mean (+/- standard deviation [SD]) height 1.76+/-0.1 (men) vs 1.62+/-0.08 m (women); body mass: 67.9+/-7.1 (men) vs 50.6+/-8.2 kg (women), ran track races at distances of 100, 400 and 800 m. The individually determined (maximal) AOD and VO(2max) were measured under controlled laboratory conditions (68.3+/-10.2 vs 60.7+/-16.1; men vs women, mL.(2) and (68.7+/-7.3 vs 55.6+/-4.3; men vs women,, respectively.
RESULTS: Track performance could be predicted using both laboratory measures, AOD and , with a high degree of accuracy: R2=76.9%, 84.8% and 89.1% for 100, 400 and 800 m, respectively. Data analysis confirmed the dominant energy supply during 100-m sprinting was the anaerobic energy supply processes, reflected as AOD. In contrast, oxidative metabolism (reflected as VO(2max)) was the dominant source of energy supply during 800-m performance.
: The results support earlier research, rather than present textbook dogma, namely that aerobic and anaerobic processes contribute equally to maximal exercise lasting approximately 60 s.

In training it isn't always possible to split up your exercise so precisely - this bit is aerobic, this bit is anaerobic. It is interesting because sport - and life - is like that - a mixture.


Christopher said...

Although that conclusion makes sense as a former 400/800 runner, I'm a little bit confused as to how they arrived at it. When they say "aerobic and anaerobic processes contribute equally to maximal exercise lasting approximately 60 s" I'm assuming they are referring to the 400, but in their results, they only report on the energy supplies for the 100 and 800. Did they just assume the 400 ought to fall somewhere between the two? That seems like an illogical jump to me.

Chris said...

I know - unfortunately this is another case in which the abstract doesn't tell the whole story.

Dr Craig S. Duncan said...

Hi Chris This has implications in game sports or multi sprint sports such as football (soccer) and training should reflect the game. Completing distances over a distance greater than what is run in a game is to me a waste. I advocate repeated sprints over distances not greater than 20-25metres for these type of sports and utilising change of direction and acceleration/deceleration is what is required. I will report to you some prelimary results of some recent work soon



Chris said...


thanks for the comment - it makes a lot fo sense. I came across a couple of interesting new football related studies that I'll put up later on that support what you are saying.