ABSTRACT
The effects of a cooling strategy following repeated high-intensity running (RHIR) on soccer kicking performance in a hot environment (>30ºC) were investigated in youth soccer players. Fifteen academy under-17 players participated. In Experiment 1, players completed an all-out RHIR protocol (10×30 m, with 30s intervals). In Experiment 2 (cross-over design), participants performed this running protocol under two conditions: (1) following RHIR 5 minutes of cooling where ice packs were applied to the quadriceps/hamstrings, (2) a control condition involving passive resting. Perceptual measures [ratings of perceived exertion (RPE), pain and recovery], thigh temperature and kick-derived video three-dimensional kinematics (lower limb) and performance (ball speed and two-dimensional placement indices) were collected at baseline, post-exercise and intervention. In Experiment 1, RHIR led to small-to-large impairments (p < 0.03;d = −0.42–-1.83) across perceptual, kinematic and performance measures. In experiment 2, RPE (p < 0.01; Kendall’s W = 0.30) and mean radial error (p = 0.057; η2 = 0.234) increased only post-control. Significant small declines in ball speed were also observed post-control (p < 0.05; d = 0.35). Post-intervention foot centre-of-mass velocity was moderately faster in the cooling compared to control condition (p = 0.04; d = 0.60). In youth soccer players, a short cooling period was beneficial in counteracting declines in kicking performance, in particular ball placement, following intense running activity in the heat.
List of abbreviations
a.u. | = | Arbitrary units |
BT | = | Best time |
CI | = | Confidence interval |
CMfoot | = | Foot centre-of-mass |
COOL | = | Cooling |
CV | = | Coefficient of variation |
DEC | = | Percentage of velocity decay |
DLT | = | Direct Linear Transformation |
EMG | = | Electromyography |
FIFA | = | Fédération Internationale de Football Association |
FOV | = | Field-of-view |
ICC | = | Intraclass correlation coefficient |
OSF | = | Open Science Framework |
PHV | = | Peak height velocity |
RHIR | = | Repeated high-intensity running |
RPE | = | Ratings of perceived exertion |
TE | = | Typical error |
TM | = | Mean time |
TT | = | Total time |
WHO | = | World Health Organisation |
WT | = | Worst time |
Data availability statement
The raw data supporting the conclusions of the current manuscript has been made publicly available at https://osf.io/bd8zv/ (Open Science Framework – OSF).
Disclosure statement
No potential conflict of interest was reported by the author(s).
Correction Statement
This article has been republished with minor changes. These changes do not impact the academic content of the article.