Brent Edwards looking parched
I remember spectating at a Southern Traverse in 2003. There were a couple of teams that had been convinced by exercise physiologists at the University of Otago, one being well known adventure racer Jim Cotter, to undergo all sorts of traumatic experiences like fat tissue sampling. Really we're talking horrific needles when you have slept for 7 hours in the last 80. Your butt is so sore you can't sit down, your feet are so sore you can't stand up, you can't stay awake and someone is sticking a needle in you!
I investigated, and it appears this research is finally reaching its fruition, with Jim Cotter's team and students producing an array of papers. If you google around you can find references to these and the other research team producing adventure racing relevant research based out of the Astrid Lindgren Childrens Hospital in Stockholm Sweden. Imagine little Swedish kids running around the countryside for days on end and people sticking needles into them...well its not quite like that..
The paper that caught my eye was "The impact of 100 hours of exercise and sleep deprivation on cognitive function and physical capacities". I like it, it sounds like an advanced form of torture, you get to a transition, you can't keep your eyes open, there is a steaming mug of pumpkin soup waiting for you, and you have to do your decision making test first...
The test involved four blocks of 20 trials in which the participant responded by pressing the left or right arrow keys of a laptop computer. Each block became more complex. The initial two blocks measured response time to identify the word or colour of non-coloured words and coloured rectangles. The final two blocks required participants to differentiate between the „name of the word‟ and the colour that the word was displayed in, responding to the colour that the word was displayed in; thus creating a conflict between colour and word recognition. For example, if the word “GREEN” was presented in yellow, the correct response was “yellow”. If its confusing now whats it like when you are wet, cold, desperate and about to embark on a 100km bike ride? Then you have to do your vertical jumps...
Explosive power was measured using a vertical jump tester (Swift yardstick, Hart Sport, New Zealand). Participants performed three standing jumps, with counter movement, with the highest taken as their maximum vertical jump. The vertical jump tester was standardised to stand-and-reach height for each participant before their first jump...and yeah did I mention needles
In the end though, and with much more detail than what I have alluded to the paper puts forward 3 key findings:
1) Only complex decision making was impaired by the race, yet the impairment was attenuated while exercising at moderate intensity (50% PPO);
2) Physical capability was only modestly impacted (all means <20%), at least relative to the extent of decrease in pace which occurs in these races, and
3) Strength and strength endurance of upper and lower limbs were affected similarly despite being used disproportionately.
The first point interests me, is consistent with my personal experience and has I think wider relevance to all forms of navigation. The authors cite a hypothesis from a guy Dinges..."the more dependent the brain becomes on the local environment to maintain wakefulness the more vulnerable it becomes to environmental monotony. Motivation and incentive can contribute to, or override, this environmental effect, but for a limited time". They sort of agree with this but also suggest that a slight increase in exercise intensity can lead to better decision making (in the experiments they used stationary cycles at transitions!). If you are at a low level of arousal (my word) and you need to make a key decision, this research perhaps suggests increasing the intensity of your exercise in lieu of making the decision.
I wonder in this if we can see the difficulty that many of us have navigating while walking/travelling at a lower speed than what we are used to? Perhaps it emphasises the need for travelling at the right intensity to stay on top of the game navigationally?
I think it is important also to understand the other end of the spectrum, desperation. Ten years ago now the National Orienteering Squad was involved in a study testing the aerobic threshold against decision making. Unsurprisingly the results were quite clear, mistakes often came during the periods of the course where people had suffered extreme physical exertion; after a big hill, after a hard track run, while trying to keep up with another competitor. In Adventure Racing, while you will not often exceed your aerobic threshold, the pyschological factor of desperation is a comparable boundary. Teams travelling intensly need to be able to identify the moments when their intensity becomes negative and results in bad decisions.
I haven't really been able to do justice to these papers so if anyone is interested, let me know and I can forward you some information.
Oh and to answer my initial question. It appears from the papers that competitors lose 1cm of standing height after a race, and 8cm of vertical jump. By my calculations that makes Brent Edwards about 10cm shorter than before he started adventure racing and unable to jump. It is clear his presence on the dance floor would have diminished as he himself has and make him less attractive to the ladies.