Pacing

Pacing and the right pacing strategy

What exactly is pacing and what does it mean? 

Pacing means achieving the fastest time over a certain distance under consideration of the altitude profile of the course. In a nutshell, it means the correct management of energy reserves during the race. 

The risk of under- and over-pacing

Everyone of us knows it: as soon as the race starts, we start running at a proper pace. But how long are we able to maintain this speed? Does it make more sense to save energy at the beginning of the race or to go straight to the front? Do I prefer to ride cautiously on the uphill and go full throttle again on the flat? Or should I attack uphill? 

To avoid the fiasco of an empty energy store and lactate legs, it is particularly important to apply an individual pacing strategy. 

Pacing strategy is described as the efficient use of energy resources during a competition so that all available energy resources are used before the end of a race, but not so far before the end of a race that a significant slowdown occurs (1-3).

Numerous race analyses have shown that in most cases, consistent performance throughout the race leads to the best results. The top riders were able to get the same power output in the last third of the race as they did in the early climbs. If a mountain bike or road bike race is a very technical course with many climbs, a good mix of acceleration and constant riding is race critical. 

Which factors influence the individual pacing strategy?

The description of the proper allocation of energy resources has been extended to include the regulation of other physiological variables, including heat storage and thus body temperature (4-6).  

For example, endurance exercise in hot and humid environments has been found to cause fatigue and a consequent decline in performance (running speed or power) as body temperature rises to critical levels above which such an effort is no longer possible (7).

The reason for the decrease in power output is that the activation of the motor units of the skeletal muscles by the brain is reduced above this critical core temperature of about 40 degrees Celsius (4-6).

A variant of the experimental manipulations of pacing strategy is the use of computer models that predict pacing strategy during competition. These computer models simulate competitions using historical performance data and generate predicted split times for each leg of the competition. Such computer models can balance the competition profile with physiological performance and elicit an individual pacing strategy. We at enduco are also working on a new type of model for this.

What are the pacing strategies? 

Abbiss and Laursen (8) describe different pacing strategies in their paper "Describing and Understanding Pacing Strategies during Athletic Competition". Here they distinguish between an "All-Out-", "Negative-", "Positive-", "Even-", "Parabolic-Shaped-", and "Variable Pacing". Reference is made to the change in speed during the races. The authors conclude that in longer races (>2 minutes), athletes tend to use more even or variable pacing strategies, which in turn are based on external factors (e.g., course geography or environmental conditions). In ultra-endurance races (>4 hours), there is also evidence that athletes progressively reduce their pace. However, whether these descriptive results represent optimal scenarios requires further exploration.

Sources 

1. Foster, C., De Koning, J. J., Hettinga, F., Lampen, J., La Clair, K. L., Dodge, C., Bobbert, M., & Porcari, J. P. (2003). Pattern of energy expenditure during simulated competition. Medicine and science in sports and exercise, 35(5), 826–831, doi: 10.1249/01.MSS.0000065001.17658.68
2. de Koning, J. J., Bobbert, M. F., & Foster, C. (1999). Determination of optimal pacing strategy in track cycling with an energy flow model. Journal of science and medicine in sport, 2(3), 266–277, doi: 10.1016/s1440-2440(99)80178-9
3. Hettinga, F. J., De Koning, J. J., Meijer, E., Teunissen, L., & Foster, C. (2007). Biodynamics. Effect of pacing strategy on energy expenditure during a 1500-m cycling time trial. Medicine and science in sports and exercise, 39(12), 2212–2218, doi: 10.1249/mss.0b013e318156e8d4
4. Marino, F. E., Lambert, M. I., & Noakes, T. D. (2004). Superior performance of African runners in warm humid but not in cool environmental conditions. Journal of applied physiology, 96(1), 124–130, doi: 10.1152/japplphysiol.00582.2003
5. Tucker, R., Rauch, L., Harley, Y. X., & Noakes, T. D. (2004). Impaired exercise performance in the heat is associated with an anticipatory reduction in skeletal muscle recruitment. European Journal of Physiology, 448(4), 422–430, doi: 10.1007/s00424-004-1267-4
6. Tatterson, A. J., Hahn, A. G., Martin, D. T., & Febbraio, M. A. (2000). Effects of heat stress on physiological responses and exercise performance in elite cyclists. Journal of Science and Medicine in Sport, 3(2), 186–193, doi: 10.1016/s1440-2440(00)80080-8
7. Nybo, L., & Nielsen, B. (2001). Hyperthermia and central fatigue during prolonged exercise in humans. Journal of Applied Physiology, 91(3), 1055–1060, doi: 10.1152/jappl.2001.91.3.1055
8. Abbiss, C. R., & Laursen, P. B. (2008). Describing and understanding pacing strategies during athletic competition. Sports Medicine, 38(3), 239–252, doi: 10.2165/00007256-200838030-00004