Background: Two types of detraining can be described: short-term detraining with a period of less than 4 weeks, and long-term detraining (period longer than 4 weeks). The purpose of this study is to verify the presence and eventually the magnitude of physiological cardiorespiratory changes in young team sport players after a period of long-term detraining.
Methods: Fourteen young soccer players (15 ± 1 year) were studied with two incremental tests at the end of the regular season and after a six-week total break period from training activities. Physiological variables were evaluated: heart rate (HR), oxygen uptake (VO₂), volume of ventilation (VE), aerobic (VA) and anaerobic (Van) running speed at thresholds and maximum effort were recorded.
Results: This study shows the magnitude of the physiological changes in young players after a period of long-term detraining. The results showed significant decreases at the end of the detraining period of VO₂ at VA of 22.7% (44.54 ± 4.56 vs. 34.41 ± 4.57 mL/kg/min, P<0.05), of 25.8% of VO₂ at VAn (54.60 ± 5.81 vs. 40.48 ± 5.07 mL/kg/min, P<0.05) and of 21.2% in VO₂ max (62.83 ± 5.77 vs. 49.46 ± 6.51 mL/kg/min, P<0.05). Speed at VA (11.5 ± 0.96 vs. 10.7 ± 0.97 km/h; P<0.05), speed at VAn (15.3 ± 1.05 vs. 14.2 ± 1.48 km/h; P<0.05), peak running speed (18.8 ± 1.20 vs. 17.2 ± 1.1 km/h; P<0.05).
Conclusion: It is likely that alteration of metabolic parameters may significantly affect the range of physical condition and especially, aerobic-anaerobic resistance and maintenance training would be advisable in young athletes during the transition period. Given the relevance of worsening demonstrated by our data, coaches should avoid very long periods of complete rest (no more than 15 days) at the end of the season.