What I think about when I think about running…..like many people my thoughts turn to the marathon and in particular, pacing strategy and hitting the wall.
Most runners go into the race with a time in mind however, often that time is unrealistic or they set off too quickly and pay a heavy price in the later stages.
So let’s take a look at pacing…. recent data correlated by prof Stephen Seiler looked at a group of athletes who had run 5k,10k, half marathon and marathon in the same year. What the data shows is a strong correlation across the distances with the regression equation almost identical in terms of relative velocity for both male and female athletes suggesting that if you don’t have speed over 5k there is no magic going to happen in the marathon.
If we were to look at the difference in velocity from 5k to the marathon we can see a difference of 113%. So if we were to take an athlete with a 5k of 20 minutes and do some simple maths we would see….
5k=4min km/6:29m [240secx1.13=271sec]
Of course this assumes you have done the training for the marathon!
So what about hitting the wall, what does it mean. In the marathon a pace that is comfortable in the 1st half of the race can become uncomfortable and sometimes intolerable in the last third.this is a result of the internal load going up and the external load becoming harder to sustain, coupled with micro trauma to the muscles sustained by the constant pounding on the surface.So what is happening is a depletion of glycogen and muscle damage as the run progresses.
But is hitting the wall inevitable; if we break the race down we would generally see a heart rate which remains stable through the first half of the race with the pace consistent to perhaps 85% of the run.However as you move into the second half the heart rate starts to increase and as you near the end of the race the pace starts to slide away either a little or a lot as as you are forced to work harder as a result of fatigue.It need not be a disaster if you have followed a good pacing strategy however the price you pay of going off too hard can be a heavy one.