Ballistic power: GPS-derived measurements suitable for the real-time monitoring of neuromuscular fatigue during repeated sprints

Power-force-velocity ( P F v ) measurements have traditionally been employed to characterize the limits of an athlete’s neuromuscular system. However, in more recent years, there has been growing interest in whether P F v metrics can also be used to define and assess training outcomes, e.g., as an indicator of performance and/or neuromuscular fatigue. Here we assess performance in a repeated sprint ability ( RSA ) test using traditional P F v measurements, alongside two novel metrics: ballistic power ( P B ) and the F v -offset, with the changes observed attributed to neuromuscular fatigue. Twenty-four physically active males (age = 26.08 ± 6.84 years) undertook the RSA test, consisting of 3 sets of 5 × 50 m maximal sprints, with each participant wearing a STATSports Apex Pro series unit to track their motion. Mixed-effect models show how power-related metrics have the largest reduction due to fatigue compared to their force and velocity counterparts, with P B showing the largest decrease of ∼ 31.8% ( − 40.2 ≤ P B ( % change ) ≤ − 23.4 , 95% CI, Cohen’s d = 1.60 ) across the RSA test performed. We demonstrate that ballistic power, P B , is the most reactive metric to athlete fatigue amongst the considered values. The described methods provide a promising, feasible tool for field-based monitoring of fatigue using routine GPS data.