Pacing the race - what is the best strategy?
Issue: Volume 27 Number 2
Background
Any coach of an athlete involved with racing over a distance knows the importance of getting the race-pace judgement correct. Going out too fast or too slow can mean the difference between first and last place in a race. Some athletes seem to have the ability to build a race, others to go out fast and hold on, others to hold the same pace throughout.
Research
A group of British sport scientists examined the effect of pacing changes on metabolism (blood lactate, heart rate, ventilation), ratings of perceived exertion, stroke kinematics (stroke count and length) and turning times in nine competitive male breaststroke swimmers. On three separate days 48 hours apart and in random order, they swam three paced 200-metre breaststroke trials, at 98 per cent, 100 per cent and at an attempted 102 per cent of their maximal 200-metre time-trial speed. Pacing was set by an audible bleep every 12.5 metres of the swim.
Findings
Blood lactate, heart rate, and breathing responses were similar between the 98 per cent and 100 per cent trials, but higher post-exercise blood lactate concentrations were observed following the 102 per cent trial. As the pace of trials increased, stroke rate was found to increase. However, during the latter stages of the 100 per cent trial, a disproportionate increase in the stroke count was observed, which led to a significant pacing error which was more obvious in the 102 per cent trial, where participants demonstrated ‘positive pacing’ and reported higher ratings of perceived exertion than for the 98 per cent trial. During the early stages of each of the trials, turn times were initially shorter the faster the pace of the trial. However, as the trials progressed, this pattern was found to reverse and turn times became longer. The positive pacing 102 per cent trial led to increases in blood lactate, heart rate and breathing and a slowing of pace at the end of the trial.
Coach’s takeout
These results suggest that as metabolic load (intensity of effort) increases, stroke rate increases to account for the fatigue of the harder effort. However, this research suggests that increasing stroke rate during near maximal efforts does not compensate for the reduction in stroke length seen in such efforts. Initially, the faster trials also showed faster turn times until later in each 200-metre swim trial, where fatigue meant slower turn times. Thus, a coach needs to be aware of this decrease in technical aspects of the event when adopting a positive pacing strategy. The research also showed that a slight 2 per cent decrease in maximal speed from 100 per cent to 98 per cent does not alter heart rate, respiration or blood lactate responses, suggesting that energy is not conserved when speeds are near maximal. However, going out at a pace 102 per cent faster than the average 200-metre swim time causes increases in stroke rate, blood lactates, heart rate and breathing, that leads to fatigue at the end of the race and thus slower finishing paces. The positive split 102 per cent trial was only completed 0.8 per cent faster than the 100 per cent even-pace trial.
Reference
Thompson, KG, MacLaren, DP, Lees, A, Atkinson, G 2004. The effects of changing pace on metabolism and stroke characteristics during high-speed breaststroke swimming. Journal of Sports Sciences. 22(2): 149–57.
