ABSTRACT
PlayerLoad is derived from a tri-axial accelerometer device and is a measure of an athlete’s external training load. Tri-axial accelerometers (Optimeye S5, Catapult Sports, Melbourne, Australia) were worn by 25 collegiate pitchers during a pitching session. Pitches included fastballs, curve balls, sliders, and changeups. Peak and sum PlayerLoad were calculated for fastballs, curve balls, sliders, and changeups. Statistical analysis included paired t-tests (p < 0.01) and effect size indexes (ESI). Peak and sum PlayerLoad were higher for fastballs compared to changeups (N = 20; ESIpeak = 0.47, p= 0.001 and ESISum = 0.13, p = 0.001, respectively). Peak and sum PlayerLoad were not different comparing fastball to curveball (N = 12; ESIpeak = 0.24, p = 0.050 and ESISum<0.01, p = 0.106) and fastball to slider (N = 12; ESIpeak = 0.32, p = 0.088 and ESISum = 0.02, p = 0.221). Fastball velocity (37.1 ± 2.1 m/s) differed from the changeup (33.8 ± 1.9 m/s; p < 0.001), curveball (32.2 ± 1.2; p < 0.001), and slider (33.8 ± 1.3 m/s; p < 0.001). Pitching workload may differ based on pitch type. Pitch counts may not capture true player fatigue due to variability in stresses resulting from different pitch types.
Acknowledgments
The authors would like to thank Sophia Ulman, Steven Heer, Justin Losciale PT, DPT, and Jason Shutt PT, DPT for their help in data collection.
Disclosure statement
No potential conflict of interest was reported by the authors.