Effects of cold water immersion on aerobic capacity and muscle strength of young footballers.

Aims: The main aim was to compare aerobic performance data, determined before «period1» and after «period2» cold water immersion in two groups of footballers (CWI and no-CWI groups).

Methods: This is an experimental study with matching and randomization. The 20 male footballers, aged 17 to 20 years, were divided into two groups (n = 10 for each) following a random draw. The two groups were age-, height- and weight matched. 1000-m race was made during the two periods. Heart-rate (HR, % of theoretical maximum HR) and hemoglobin oxygen saturation (Oxy-sat, %) were measured before and after the race, and the time of the race (min) was noted. An Oxy-sat decrease > 4 points retained the diagnosis of exercise-induced desaturation. Eight CWI sessions (one per week), until the hip in a standing position (10 min; temperature: 11-12 °C) were performed.

Results: The two groups were age-, height- and weight matched. Comparatively to the race time of «period1», this of «period2» was decreased in the CWI group (3.21±0.04 vs. 3.15±0.04 min) and was increased in the no-CWI group (3.23±0.05 vs. 3.27±0.07 min). Comparatively to the HRs (before, after the race) of «period1», these of «period2» were decreased in the CWI group (36±1 vs. 34±1%; 56±3 vs. 44±2%) and were increased in the no-CWI group (35±2 vs. 36±1%; 55±2 vs. 57±2%). Comparatively to the after race Oxy-sat' of the «period1», this of «period2» was increased in the CWI group (96±1 vs. 98±0%) and was decreased in the no-CWI group (96±1 vs. 95±1%). While in the CWI group, the percent of desaturators was decreased between «period1» and «period2» (30 vs. 0%), in the no-CWI group, percentages remained similar (50 vs. 90%).

Conclusion: CWI improves aerobic capacity and muscle strength of young footballers.