Fatigue index and anaerobic power: a two - case study of the running anaerobic sprint test in active sportsmen different sports
Background and purpose Fatigue is a physiological phenomenon that reduces the ability of muscles to maintain maximal force during repeated activities. Anaerobic capacity and the Fatigue Index (FI) are key indicators of the body’s ability to sustain explosive power, and the Running Anaerobic Sprint Test (RAST) is a recognized tool for their assessment. Purpose: this study was to assess the anaerobic abilities of active sportsmen, using the RAST, with a focus on Peak Power (PP) and the Fatigue Index (FI). Material and methods The study included two male active sportsmen. (U.G., 70 kg and A.V., 85 kg) who performed six 35-meter sprints with 10 seconds of rest between sprints. Sprint time and lower limb power (W) were measured, while FI was calculated based on the difference between maximal and minimal power. Results Both participants showed a linear decline in speed and power during repeated sprints. A.V. achieved a higher level of power and a lower FI (11.6%) compared to U.G. (18 %). Power decreased from (both) sample 732W to 515W, while total average sprint time increased by 0.57s. Conclusions The Rast aerobic sprint test is an effective and practical tool for assessing anaerobic capacity and monitoring individual progress. The results confirm lactate accumulation and muscle fatigue. Targeted high-intensity anaerobic training can reduce FI and improve the anaerobic capacity of physical education and sport students.