Warm-up durations in a hot-dry climate affect thermoregulation, mean power-output and fatigue, but not peak power in specific soccer repeated-sprint ability

Abstract

Background This study addressed the lack of data on the effect of warm-up (WU) duration in hot-dry climate (~ 30 °C; ~ 18% RH), on thermoregulation, muscular power-output, and fatigue after specific soccer repeated-sprint test (RSA). Methods Eleven amateur soccer players participated in a cross-over randomized study and they underwent the Bangsbo repeated-sprint test, after three WU durations (i.e. WU10, WU15 and WU20 min) at 70% of MAV, and on different days. Peak power (PP), mean power (MP) and the fatigue index (FI) were recorded and analyzed. Likewise, heart rate (HR), tympanic temperature (Ttym), mean body temperature (MBT) and rating of perceived exertion (RPE) were recorded during each session. Results The repeated measure ANOVA showed that MP improved after WU15 in comparison to WU10 and WU20 (p = 0.04 and p = 0.001; respectively). Nonetheless, no significant effect on PP was recorded after all WU durations. FI during RSA increased after WU20 in comparison to WU15 and WU10 (p < 0.001 and p = 0.003; respectively). Higher RPE values (p < 0.001) were recorded after WU15 and WU20 in comparison to WU10 duration. The two-way ANOVA showed higher ΔTtym and ΔMBT values after WU15 and WU20 compared to WU10 (p = 0.039 and p < 0.001for Ttym; p = 0.005 and p < 0.001 for MBT, respectively). Conclusions The WU15 at 70% of MAV better assists mean power-output during soccer RSA in hot-dry (~ 30 °C; 18% RH) climate, but not peak power. Reducing WU duration up to 10 min seems to be insufficient to induce beneficial physiological changes necessary for optimizing repeated-sprint performance, while its extension up to 20 min remains detrimental for muscular power and induces higher fatigue.

Responses of soccer players performing repeated maximal efforts in simulated conditions of the FIFA World Cup Qatar 2022: A holistic approach

“…This increase was shown to be a major factor responsible for improving nerve conduction velocity, enzymatic activities, oxygen delivery to muscles as well as for decreasing muscular viscous resistance [56]. Similarly, an increase in muscle temperature was shown to be responsible for a ~4% improvement of muscular leg power for each elevated 1˚C [54].…”

“…Moreover, Yamaguchi et al [53] reported Pmax in HOT (35˚C) 3% higher than in NC (20˚C). Frikha et al [54] noted that the higher mean power-output values in HOT (30˚C) conditions may be related to the higher increase in core temperature [55]. This increase was shown to be a major factor responsible for improving nerve conduction velocity, enzymatic activities, oxygen delivery to muscles as well as for decreasing muscular viscous resistance [56].…”

“…Cardiopulmonary fitness is also often cited as a significant characteristic of success in soccer due to the large distances and continual dynamic movement patterns players are required to perform during a game [57]. Maximal or very high-intensity exercise in the heat causes a relevant impairment in oxygen delivery to the exercising muscles related to cardiac and muscle blood flow decreases [47,54]. Drust et al [29] reported lower accumulated oxygen consumption during repeated sprints in HOT (40˚C) than in NC (20˚C) conditions.…”