Recovery of kicking kinematics and performance following repeated high-intensity running bouts in the heat: Can a rapid local cooling intervention help young soccer players?

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.

KEYWORDS:

• Cryotherapy
• heat environment
• three-dimensional kinematics
• technique
• accuracy
• football

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.

Additional information

Funding

This study was funded by the São Paulo Research Foundation (FAPESP) under fellowship number #2018/02965-7 (received by Luiz Henrique Palucci Vieira - doctorate) and in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance code [001].