Author(s): BURKERT, F., RASP, D.M., VOGL, A.M., PATERNOSTER, F.K., Institution: TECHNICAL UNIVERSITY OF MUNICH, Country: GERMANY, Abstract-ID: 2519

INTRODUCTION:
The acute performance-enhancing effects of explosive conditioning contractions (CCs) are well documented [1,2]. However, it remains unclear whether additional explosive CCs still provide benefits when performed after a comprehensive warm-up in strength sport settings. This study examined the effects of explosive CCs performed after a squat-specific warm-up (SWU) on concentric and eccentric peak force, work, power, and rate-of-force development (RFD).
METHODS:
Twenty resistance-trained males (21.9 ± 2.9 years) completed two randomized experimental conditions (jump and control) in a crossover design, carried out on separate days, preceded by a familiarization session. During familiarization, participants performed a 1-repetition maximum (1RM) squat in a Smith machine to determine SWU loads. The SWU consisted of 10 repetitions with the empty bar, 5 at 30% 1RM, 3 at 50% 1RM, and single repetitions at 70%, 80%, and 90% 1RM. Four minutes of rest were prescribed between the last three sets. The two experimental conditions were SWU + explosive CCs (JUMP) and SWU without CCs (CONTROL). For the CCs in JUMP, five maximal depth jumps (40 cm) were performed 5 min after the SWU. In both conditions, participants performed three isokinetic leg press sets on the Isomed200 leg press device (LP), each comprising five consecutive maximal eccentric and concentric repetitions at a linear velocity of 450 mm/s and 200 mm/s, respectively. This was done before the SWU (PRE) and after the SWU or SWU + CCs (POST1, POST2). Therefore, the sequence of JUMP was PRE, SWU, 5 min rest, CCs, 2 min rest, POST1, 8 min rest, POST2. The sequence CONTROL was PRE, SWU, 7 min rest, POST1, 8 min rest, POST2. During LP repetitions, force, time, and positional data were extracted. Repeated measures ANOVA were used to evaluate the effect of the CCs on the aforementioned outcome parameters over the three occasions (PRE vs. POST1 vs. POST2). Additionally, PRE-POST1, PRE-POST2, and POST1-POST2 changes were calculated for both conditions.
RESULTS:
A repeated measures ANOVA observed no significant main effects for condition, time and condition * time interactions for maximal force, work, maximal or average power, or RFD in both the concentric or eccentric repetitions (all p > .05). Paired t-tests for PRE-POST1, PRE-POST2, and POST1-POST2 changes did not show any significant differences between conditions (all p > .05).
CONCLUSION:
Under the present SWU intensities and recovery intervals, the addition of explosive depth jumps following a squat-specific warm-up did not enhance subsequent LP performance. These findings suggest no additive PAPE effect of explosive CCs after a SWU when implemented shortly before maximal dynamic strength assessments, which is in line with current research on warm-ups and CCs [3]. Further research should investigate different recovery durations and CC intensities.

[1] Wilson et al., 2013, J Strength Cond Res
[2] Blazevich & Babault, 2019, Frontiers in Physiology
[3] Xu et al., 2025, Sports Medicine