Assessment of the body response to specific fatigue exercise protocol saft90 in u16 soccer players

Abstract

Background: SAFT90 is a specific multidirectional fatigue protocol that imitates the internal and external load of soccer match-play. Objective: The aim of the study was to evaluate the impact of SAFT90 on lactate production, heart rate (HR) and rate of subjective perceived exertion (RPE) expressed by Borg scale (6–20). Methods: Fourteen male elite junior soccer players (age 15.9 ± 0.2 years, stature 180.8 ± 5.5 cm, body mass 69.8 ± 5.8 kg, body fat 8.1 ± 3.2%, VO2 max 57.6 ± 4.7 ml ⋅ kg–1 ⋅ min–1, maximum heart rate 192.8 ± 4.6 beats ⋅ min–1) participated in this study. Lactate concentration, HR and RPE were monitored during specific fatigue exercise protocol SAFT90. Results: Results of HR showed mean values of 153 ± 15 beats ⋅ min–1, mean blood lactate concentration was 1.9 ±0.5 mmol ⋅ L–1. A mean value of RPE was 11.0 ± 1.4 that corresponds to “fairly light” exercise. No significant change was found between consecutive SAFT90 stages for HR and lactate concentration. For Borg scale, there were significant increases between stages 20 min and 45 min and between stages 70 min and 90 min. Change between stages 45 and 70 min was not significant. Conclusions: In respect to study results, we suggest that specific fatigue protocol SAFT90 applied in U16 soccer players appears to be insufficient in terms of exercise intensity to achieve comparable lactate concentration, HR and RPE values with a soccer match.