The Priming Effect of a Heavy or Very Heavy Resisted Sled Sprint-Based Conditioning Activity on Subsequent Unresisted Sprint Performance in Team Field Sport Athletes.

Monahan, M and Egan, B. The priming effect of a heavy or very heavy resisted sled sprint-based conditioning activity on subsequent unresisted sprint performance in team field sport athletes. J Strength Cond Res 37(1): 91-97, 2023-The effect of resisted sled sprinting (RSS) on postactivation performance enhancement (PAPE) was investigated in team field sport athletes (n = 28; m and female, 15 and 13; age, 22.1 ± 2.5 years; height, 1.77 ± 0.11 m; body mass [BM], 75.1 ± 16.4 kg). After a standardized warm-up, unresisted sprint (URS) performance was measured over 10- and 20-m (PRE) followed by a conditioning activity (CA) consisting of 3 × 20 m RSS. Unresisted sprint performance was then measured again at 30 seconds and 4, 8, 12, 16, 20, and 24 minutes after CA. The effect of heavy (H-RSS) or very heavy (VH-RSS) sled loads were compared during 2 separate visits using a randomized crossover design. Heavy-resisted sled sprinting and VH-RSS loads corresponded to a velocity decrement (Vdec) of 17.3 ± 3.6%Vdec (20.0 ± 2.3%BM) and 52.9 ± 3.8%Vdec (64.3 ± 7.0%BM), respectively. Unresisted sprint performance after CA was slower than PRE over 10- and 20-m (both p < 0.001 for time). The decline in URS performance over 20-m was greater in VH-RSS (time × sled load interaction, p = 0.033). However, after extraction of the fastest sprint times after CA, the fastest sprint time for 10-m improved after H-RSS by 0.026 (0.001, 0.050) seconds (p = 0.040; d = 0.21) but not after VH-RSS (p = 0.054; d = 0.14). The fastest sprint times for 20-m were similar to PRE after H-RSS and VH-RSS. No sex-specific differences were observed. Given the high intersubject variability in the magnitude of improvement, and for the time point at which the fastest sprint occurred, there remains questionable practical value to an RSS-based CA as a means to induce a PAPE for URS performance.