In my review this week is my summary of a paper looking at soccer warm ups. ( Sign up to get it each week)
In most sports, a warm-up is performed with an aim to prepare the body for high level performance and to prevent injuries when performing at that high level. In soccer, players regularly need to produce maximal sprint efforts, also called repeated sprint ability. This ability is often trained for and tested with 6–18 sprints, varying between 20–40 m, with recoveries of between 15–30 seconds. To perform well on these sprints, which can make a difference in ball contests, it is important that the players have warmed-up, since including a warm-up has shown enhanced performance compared with no warm-up.
It is important that the warm-up is of sufficient duration to elevate baseline VO2, while causing minimal fatigue. Earlier, it was found that a minimum of 10 minutes warm-up is needed to enhance performance, mainly as this increases muscle temperature.
The aim of this study was to compare the effects of a long (general and task-specific parts) warm-up with a shorter (only task-specific, high intensity part) warm-up upon repeated sprint performance in soccer players.
Ten experienced soccer players playing in the third–fifth division of the national league (age 21.9 ± 1.9 yr, body mass 77.7 ± 8.3 kg, body height 1.85 ± 0.03 m) participated in the study.
The subjects performed the two warm-up protocols, a long warm-up (20 minutes: LWup) and a short warm-up (10 minutes: SWup), followed by a repeated sprint test. The repeated sprint test consisted of 8 x 30 m sprints with a new start every 30th second.
The best and average sprint times were calculated, together with the total sprint time of all eight sprints and the fatigue index. The fatigue index was calculated by the formula, Fatigue = (100 x [total sprint time – ideal sprint time] – 100), in which the ideal sprint time was the best sprint time multiplied by the number of sprints.
Heart rate was measured every fifth second with a heart rate belt. Blood lactate concentration was taken from the index finger three minutes after completion of the repeated sprint test. The received perception exertion (RPE) was measured on a Borg scale of 6–20, in which 6 indicated no exertion and 20 indicated maximal perceived exertion.
The performance related physiological and perceptual variables (heart rate, blood lactate concentration and RPE) recorded before warm-up, after warm-up, after the repeated sprint test and three minutes after the repeated sprint test were used for further analysis.
To test performance related variables, a 2 (warm-up protocol: long vs. short) x 4 (time: before warm-up, after warm-up, after repeated sprint test and three minutes after repeated sprint test) repeated ANOVA was used.
No significant difference between the two warm-up protocols was found for either of the repeated sprint test parameters (total sprint time: 35.99 ± 1.32 s [LWup] and 36.12 ± 0.96 s [SWup]; best sprint time: 4.32 ± 0.13 s [LWup] and 4.30 ± 0.10 s [SWup] and % sprint decrease: 4.16 ± 2.15 % [LWup] and 5.02 ± 2.07 % [SWup]).
However, the performance related physiological and perceptual parameters showed different results. Although the average heart rate over the two protocols did not differ significantly, RPE and heart rate were significantly different between the two protocols and the blood lactate concentration was not significantly different.
Post hoc comparison showed that RPE was significantly higher for the long warm-up after the warm-up, the repeated sprint test and three minutes after that. The heart rate was only significantly higher straight after the long warm-up and after the following repeated sprint test.
The authors concluded that, with the exception of RPE and heart rate, there were no significant differences in the repeated sprint performance variables between the two warm-up protocols. The findings indicate that the short warm-up is good enough and therefore more time could be dedicated to important soccer training skills.