Muscle temperature and sprint performance during soccer matches: beneficial effect of re-warm-up at half-time

The relationship between quadriceps muscle temperature
(Tm) and sprint performance was evaluated during soccer
matches in 25 competitive players. In one game, Tm was
determined frequently (n 5 9). In another game, eight
players performed low-intensity activities at half-time
(re-warm-up, (RW), whereas another eight players recovered passively (CON). Tm was 36.070.2 1C at rest and
increased (Po0.05) to 39.470.2 1C before the game and
remained unaltered during the first half. At half-time, Tm
decreased (Po0.05) to 37.470.2 1C, but increased
(Po0.05) to 39.270.2 1C during the second half. In CON
and RW, Tm and core temperature (Tc) were similar before
and after the first half, but 2.170.1 and 0.970.1 1C higher
(Po0.05), respectively, in RW prior to the second half. At
the onset of the second half, the sprint performance was
reduced (Po0.05) by 2.4% in CON, but unchanged in RW.
The decrease in Tm was correlated to the decrease in
performance (r 5 0.60, Po0.05, n 5 16). This study demonstrates that in soccer, the decline in Tm and Tc during
half-time is associated with a lowered sprint capacity at the
onset of the second half, whereas sprint performance is
maintained when low-intensity activities preserve muscle
temperature.