Reducing Muscle Temperature Drop after Warm-up Improves Sprint Cycling Performance

FAULKNER, S. H., R. A. FERGUSON, N. GERRETT, M. HUPPERETS, S. G. HODDER, and G. HAVENITH. Med. Sci. Sports Exerc., Vol. 45, No. 2, pp. 359-365, 2013. Purpose: This study aimed to determine the effect of passive insulation versus external heating during recovery after a sprint-specific warm-up on thigh muscle temperature and subsequent maximal sprint performance. Methods: On three separate occasions, 11 male cyclists (age = 24.7 +/- 4.2 yr, height = 1.82 +/- 0.72 m, body mass = 77.9 +/- 9.8 kg; mean +/- SD) completed a standardized 15-min intermittent warm-up on a cycle ergometer, followed by a 30-min passive recovery period before completing a 30-s maximal sprint test. Muscle temperature was measured in the vastus lateralis at 1, 2, and 3 cm depth before and after the warm-up and immediately before the sprint test. Absolute and relative peak power output was determined and blood lactate concentration was measured immediately after exercise. During the recovery period, participants wore a tracksuit top and (i) standard tracksuit pants (CONT), (ii) insulated athletic pants (INS), or (iii) insulated athletic pants with integrated electric heating elements (HEAT). Results: Warm-up increased T-m by approximately 2.5 degrees C at all depths, with no differences between conditions. During recovery, T-m remained elevated in HEAT compared with INS and CONT at all depths (P < 0.001). Both peak and relative power output were elevated by 9.6% and 9.1%, respectively, in HEAT compared with CONT (both P < 0.05). The increase in blood lactate concentration was greater (P < 0.05) after sprint in HEAT (6.3 +/- 1.8 mmol.L-1) but not INS (4.0 +/- 1.8 mmol.L-1) versus CONT (4.1 +/- 1.9 mmol.L-1). Conclusions: Passive heating of the thighs between warm-up completion and performance execution using pants incorporating electrically heated pads can attenuate the decline in T-m and improve sprint cycling performance.