Plantar flexor neuromuscular adjustments following match-play football in hot and cool conditions

We assessed neuromuscular fatigue and recovery of the
plantar flexors after playing football with or without
severe heat stress. Neuromuscular characteristics of the
plantar flexors were assessed in 17 male players at baseline and ∼30 min, 24, and 48 h after two 90-min football
matches in temperate (∼20 °C and 55% rH) and hot
(∼43 °C and 20% rH) environments. Measurements
included maximal voluntary strength, muscle activation,
twitch contractile properties, and rate of torque development and soleus EMG (i.e., root mean square activity)
rise from 0 to 30, −50, −100, and −200 ms during maximal
isometric contractions for plantar flexors. Voluntary activation and peak twitch torque were equally reduced
(−1.5% and −16.5%, respectively; P < 0.05) post-matches
relative to baseline in both conditions, the latter persisting for at least 48 h, whereas strength losses (∼5%) were
not significant. Absolute explosive force production
declined (P < 0.05) 30 ms after contraction onset independently of condition, with no change at any other epochs.
Globally, normalized rate of force development and
soleus EMG activity rise values remained unchanged. In
football, match-induced alterations in maximal and rapid
torque production capacities of the plantar flexors are
moderate and do not differ after competing in temperate
and hot environments.