Post-Isometric Back Squat Performance Enhancement of Squat and Countermovement Jump

Abstract

The effectiveness of isometric conditioning activity (CA) is not well described in terms of the level of performance enhancement and the presence of a stretch and shortening cycle in subsequent explosive tasks. Therefore, the aim of this study was to evaluate the effect of a maximum isometric squat as the CA and a subsequent squat jump (SJ) and countermovement jump (CMJ) height. A total of 31 semi-professional handball and soccer players were randomly assigned to two different conditions: (i) 3 sets of 3 repetitions (each lasting 3 s) of maximum isometric back squats (EXP), and (ii) no CA (CTRL). The jump height measurements were performed 5 min before the CA and approximately at the 4th and 8th minute following the completion of the CA. Due to the high inter-individual variability in the potentiation responses, the best value obtained post-CA was also analyzed. The SJ height significantly increased from baseline to the 8th minute post-CA (p = 0.004; ES = 0.31; Δ = +3.1 ± 5.0%) in the EXP condition. On the other hand, the CMJ height was significantly higher in the 4th (p = 0.001; ES = 0.23; Δ = +2.7 ± 3.7%) and 8th minute post-CA (p = 0.005; ES = 0.32; Δ = +3.6 ± 5.7%) in comparison to baseline during the EXP condition. Furthermore, SJ height significantly increased from baseline to the best time-point during the EXP (p < 0.001; ES = 0.47; Δ = +4.9 ± 4.9%) and CTRL (p = 0.038; ES = 0.21; Δ = +2.5 ± 5.8%) condition. Moreover, the CMJ height was significantly higher at the best time-points than at the baseline during EXP (p < 0.001; ES = 0.53; Δ = +5.6 ± 4.7%) and CTRL (p = 0.002; ES = 0.38; Δ = +3.1 ± 5.2%) condition. The findings from this study indicate that a maximum isometric squat, used as a CA, effectively improved SJ and CMJ height. This suggests that the presence or absence of a stretch and shortening cycle in both CA and post-CA tasks does not significantly impact the post-activation performance enhancement response.

Postsubmaximal Isometric Full Squat Jump Potentiation in Trained Men

“…Some difficulties can be found when comparing improvement peaks between studies due to measurements performed at various time points. Nonetheless, enhancement mostly became visible approximately 3 minutes after the protocol in the current study and others (16,36,39). However, individualization of the CA requires emphasis because of the various responses among subjects after completing protocols (36).…”

The sex effects on changes in jump performance following an isometric back squat conditioning activity in trained adults

“…One of the most crucial factors for effective PAPE is appropriate intensity. Indeed, an effort of approximately 80%-RM is submaximal ( Seitz and Haff, 2016 ; Dobbs et al, 2019 ), though positive effects are observed with higher and lower loads ( Gołaś et al, 2017 ; Vargas-Molina et al, 2021 ) or by using voluntary contractions ( Kalinowski et al, 2022 ; Spieszny et al, 2022 ). In this regard, the intensity of the CA and rest intervals are also crucial ( Dobbs et al, 2019 ).…”

“… Vargas-Molina et al (2021) also observed jump improvement after isometric squats, though they used a slightly higher external load. In addition, Spieszny et al (2022) employed an isometric squat with an immovable bar to improve jump height and demonstrated that volitional isometric contraction could increase jump height. Tillin and Bishop (2009) postulated that isometric effort might engage more high-threshold motor units and is less fatigue-resistant, indicating that caution is needed when isometry is used.…”

“…Isometry has many benefits associated with less energy expenditure, meaning that fatigue is limited and neural drive is improved, which may enhance performance ( Duchateau and Hainaut, 1984 ; Baudry and Duchateau, 1985 ; Cady et al, 1989 ). Indeed, post-activation enhancement protocols based on isometry (have positively impacted performance in several studies ( Rixon et al, 2007 ; Hirayama, 2014 ; Spieszny et al, 2022 ), although others have shown them to have no benefits ( Harat et al, 2020 ). In this regard, it is necessary to emphasize that many factors other than the introduced protocol can influence the PAPE effect.…”

Post-activation effects of accommodating resistance and different rest intervals on vertical jump performance in strength trained males

“…A variety of PAPE application methods were found to enhance performance. Any type of muscle contraction can be effective (only eccentric [ 8 – 10 ], isometric [ 10 – 14 ], eccentric-concentric [ 15 ] and only concentric [ 16 ]) as well as using additional training equipment such as flywheel devices [ 17 , 18 ] or accommodating resistance [ 18 – 25 ]. It is important to determine the most efficient one for the individual as it should be as specific as possible to its sport.…”