Heart rate response does not differ between pitch types in college baseball pitchers

Fatigue has been observed to effect pitching velocity, performance and pain. Pitch counts are a sub-optimal substitute to quantify pitching physiologic stress. Heart rate (HR) response is conducive to quantify physiologic stress. Currently, there is a paucity of literature investigating HR response between different pitch types. It is hypothesised that different pitch types will have divergent HR responses during pitching. A gyroscope, triaxial accelerometer device (Optimeye S5, Catapult Sports, Melbourne, Australia) and HR monitor were worn by 25 collegiate pitchers during a pitching session. Individual pitch-type velocities were recorded for fastballs, curveballs, sliders and changeups. All HR was normalized to age predicted maximal HR (%HRmax), for each pitch type. Statistical analysis included paired t-tests (p < .01) and effect size indexes (ESI). %HRmax was lower for fastball compared to changeup (p < 0.01); however, when ESI’s were calculated, no difference was observed (ESI < 0.01). There was no difference in %HRmax between fastball to curveball (ESI < 0.01, p = 0.75) and fastball to slider (ESI < 0.02, p = 0.10). No meaningful difference in %HRmax was observed between fastball, curveballs, slider and changeups. Future studies are required to understand physiological stress responses beyond heart rate for different pitch types.