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Force‐velocity profile changes with forearm wearable resistance during standing start sprinting

2019; Taylor & Francis; Volume: 20; Issue: 7 Linguagem: Inglês

10.1080/17461391.2019.1686070

1746-1391

Paul Macadam, Megna Mishra, Erin H. Feser, Aaron Uthoff, John Cronin, James Zois, Ryu Nagahara, Farhan Tinwala,

Sport Psychology and Performance

Abstract Horizontal force‐velocity (F‐V) profiling is a strategy to assess athletes’ individual performance capabilities during sprinting. This study investigated the acute changes in F‐V profiles during sprinting of fourteen collegiate male sprinters with a mean 100‐m sprint time of 11.40 ± 0.39 s, from a split‐stance starting position. The subjects sprinted 30‐m with, and without, wearable resistance (WR) equivalent to 2% body mass, attached to their forearms. Sprinting time at 5, 10, 20, and 30‐m was assessed using laser technology. External horizontal F‐V relationships were calculated via velocity‐time signals. Maximal theoretical velocity ( V 0 ), theoretical relative and absolute horizontal force ( F 0 ), and horizontal power ( P max ) were determined from the F‐V relationship. Paired t‐tests were used to determine statistical differences ( p ≤ 0.05) in variables across conditions with Cohen's d as effect sizes (ES) calculated to assess practical changes. Sprint times at 10‐m and beyond were significantly increased (1.9–3.3%, p 0.01–0.03, ES 0.46–0.60) with WR compared to unloaded sprinting. The only significant change in F‐V with the WR condition was found in relative P max system (−6.1%, p 0.01, ES 0.66). A small decrease was reported in V 0 (−1.0%, p 0.11, ES 0.27), with small to medium ES decreases reported in F 0 (−4.8% to −6.1%, p 0.07–0.21, ES 0.25‐0.51) and P max (−4.3% to −4.6%, p 0.06–0.08, ES 0.32–0.45). The greater changes to F 0 and P max suggest that forearm WR may be a possible training tool for athletes who wish to focus on force and power adaptation during sprint acceleration from a standing start.