The Effects Of Practice On Maximal Force And Low-Frequency Fatigue In Collegiate Basketball Players

Abstract

Low-Frequency Fatigue (LFF) refers to the disproportionate loss of force at low as compared to high firing frequencies. LFF is thought to manifest during high intensity, moderate-to high-force, repetitive eccentric, or stretch-shortening cycle activities, similar to the demands of basketball. PURPOSE: Therefore, the purpose of the present study was to examine the effects of basketball practice on maximal isometric force and LFF. METHODS: Eleven NCAA Division 1 basketball players (Males = 6 and Females = 5) performed a Maximal Voluntary Isometric Contraction (MVIC) and neuromuscular electrical stimulation of the knee extensors at a high and low frequency before (Pre), immediately after (Post) and 24-hours (24Post) following a basketball practice during the preseason. Athletes wore Inertial Measurement Units to capture the external training load (eTL) of the practice. The ratio of force produced during the low to high frequency muscle stimulation was used as an index of LFF. A one-way repeated measures analysis of variance was performed to determine differences in MVIC and LFF across time, with significance set at p ≤ 0.05. Effects sizes (Cohen’s d) were calculated for pairwise comparisons and interpreted as trivial (0-0.19), small (0.20-0.49), medium (0.50-0.79), and large (0.80 and greater). RESULTS: The average of the eTL parameters during practice were PlayerLoad = 636.5 ± 66.1 arbitrary units (au); PlayerLoad per Minute = 4.76 ± 0.69au; Total Jumps = 143.8 ± 53.0 count (ct); Inertial Movement Analysis (IMA)_High = 39 ± 20ct; IMA_Medium = 135 ± 53ct; IMA_Low = 582.8 ± 156ct. There was a significant time effect for MVIC (p = 0.031), but post-hoc pairwise comparisons revealed no significant difference across time (p > 0.05). There was a significant time main effect for LFF (Pre = 0.515 ± 0.025; Post = 0.483 ± 0.038; 24Post = 0.513 ± 0.033, p = 0.019), with post-hoc pairwise comparisons revealing no significant difference from Pre- to Post-practice (p = 0.104), but did exhibit a large negative effect (d = 1.0). There was a significant increase from Post- to 24Post-practice (p = 0.039, d = 0.84). CONCLUSIONS: Based on these preliminary findings it appears basketball practice induces LFF in collegiate basketball athletes that recovers back to baseline within 24 hours of the bout. Although LFF was present, MVIC appeared unaffected.