October 2023

Acute effects of unilateral and bilateral conditioning activity on countermovement jump, linear speed, and muscle stiffness: A randomized crossover study

Authors: Piotr Biel 1, Mateusz Zubik 1, Aleksandra Filip-Stachnik 2, Paulina Ewertowska 3, Michal Krzysztofik 2, 4


  1. Department of Sport and Physical Education, AGH University of Science and Technology, Krakow, Poland
  2. Institute of Sport Sciences, The Jerzy Kukuczka Academy of Physical Education in Katowice, Katowice, Poland
  3. Division of Clinical Physiotherapy, Faculty of Physical Education, Gdansk University of Physical Education and Sport, Gdansk, Poland
  4. Department of Sport Games, Faculty of Physical Education and Sport, Charles University in Prague, Prague, Czech Republic

Journal: PLOS ONE - October 2023, Volume 18, Issue 10, Article no. e0292999 (DOI: 10.1371/journal.pone.0292999)

Purpose: Evidence directly comparing the effects of bilateral and unilateral conditioning activities is limited. Therefore, the aim of this study was to assess the acute effect of unilateral and bilateral conditioning activity on vastus lateralis stiffness, countermovement jump parameters, and 10 m sprint.

Methods: Twelve semi-professional basketball players participated in this study (age: 23 ± 4 yrs; body mass: 84.7 ± 10.6 kg; body height: 192 ± 6 cm; basketball training experience: 11 ± 4 yrs) performed four experimental sessions to compare the acute effects of bilateral, stronger-only, weaker-only lower limb or no conditioning activity on vastus lateralis stiffness, countermovement jumps variables (height; peak velocity; peak force, contraction time, countermovement depth, and modified reactive strength index and 10 m sprint time. Measurements were performed 5 minutes before and in the 5th and 10th minutes after CA.

Results: Bilateral conditioning activity significantly increase the countermovement jump height (p = 0.002; ES = 0.71) and the reactive strength index modified (p = 0.010; ES = 0.59). Moreover, a significantly higher peak force in the stronger than in the weaker limb was found (p<0.001) without any differences between conditions and time points (p>0.05). However, there were no significant (p>0.05) interactions and effects of conditions or time-point in the case of the other countermovement jump variables, vastus lateralis stiffness, and 10m sprint time.

Conclusion: Unilateral and bilateral drop jumps (3 sets of 5 repetitions) did not affect the vastus lateralis stiffness and time of the 10m sprint. However, only bilateral drop jumps effectively enhanced the countermovement jump height and modified reactive strength index. Bilateral drop jumps might be a useful part of a warm-up to improve jumping performance in basketball players.


Keywords: body limbs, stiffness, sports, running, human performance, jumping, material fatigue, musculoskeletal mechanics

The results of this study showed that 3 sets of 5 repetitions of single leg DJ performed by both the stronger and the weaker limb did not contribute to a significant improvement in subsequently performed CMJ and 10m sprint as well as did not affect the symmetry between the limbs. On the other hand, the bilateral DJ significantly improved the CMJ jump performance, but not the 10m sprint time in the studied group of basketball players. Coaches and practitioners could use bilateral DJs as the CA during complex training sessions or as part of a pre-competition warm-up to acutely improve jumping performance. However, the individuals should not expect an increase in 10m sprint performance, and changes in vastus lateralis stiffness.