Author(s): FUCHS, P., CHUANG, W.H., LIN, S.D., NAGAHARA, R., Institution: NATIONAL TAIWAN NORMAL UNIVERSITY, Country: TAIWAN, Abstract-ID: 216

INTRODUCTION:
Literature suggests that plyometric and ballistic drills induce post-activation potentiation and acute power enhancement [1]. Many studies have reported positive effects of “plyometric” or “ballistic”-labelled warm-ups on sprint performance, often blurring the distinct neuromuscular targets of stretch-shortening actions versus concentric high-velocity force generation [1,2]. A previous conference study reported no benefits of plyometric, ballistic, or combined warm-ups compared with a traditional protocol [3]. That study was likely underpowered (n=15) and limited to well-trained, competitive sprinters. The present study aimed to expand that work by adding 15 participants (athletic non-sprinters) and pooling both cohorts to investigate warm-up effects in individuals with different performance levels, thereby increasing statistical power and broadening the scope while retaining comparable procedures.
METHODS:
In addition to 15 competitive sprinters [3], 15 athletic non-sprinters completed four sessions, separated by 24 hours, in a randomized-order repeated-measures design. Each session began with 5 minutes of low-intensity jogging, then one 10-minute warm-up routine (traditional control, plyometric, ballistic, or combined plyometric-ballistic), followed by two preparatory sprints and a final 60 m sprint as the test trial. Timing gates obtained split times at 10 m, 20 m, 30 m, and 40 m. Based on split times and individual characteristics, a sprint acceleration spreadsheet [4] estimated maximum horizontal force, maximum power output, and maximum velocity. Two 960-Hz cameras obtained step length, flight time, and contact time at the start and at 40 m. Two-way repeated-measures ANOVA tested the effects of four warm-ups in two cohorts on split times, kinetics, and kinematics (start and 40 m) at p<0.05.
RESULTS:
None of the 13 tests showed main effects of warm-up (p=0.16–0.92, pη2=0.01–0.12) or warm-up by cohort interactions (p=0.19–0.98, pη2=0.00–0.12). Cohort showed main effects in all split times (p<0.001, pη2=0.59–0.74) and in five out of nine kinematics and kinetics (p<0.01, pη2=0.48–0.79).
CONCLUSION:
The pooled findings corroborate the prior conference study [3] and previous research that reported no improvement in sprint performance when compared with a standard warm-up [5]. The absence of benefits is unlikely to be explained by low statistical power or by a population-specific response. These data strengthen the suspicion that plyometric and ballistic warm-ups do not provide substantial advantages over well-designed traditional practices. Previous studies may report positive effects partly because control warm-ups were suboptimal. Future research should implement best-practice control protocols to ensure fair comparisons.

REFERENCES
1) Maloney et al. Sports Med 2014
2) Turner et al. J Strength Cond Res 2015
3) Chuang et al. ECSS 2025
4) Samozino et al. Scand J Med Sci Sports 2015
5) Gil et al. Int J Environ Res Public Health 2019