Fabrício E Rossi1,2, Brad J Schoenfeld3, Skyler Ocetnik1, Jonathan Young1, Andrew Vigotsky4, Bret Contreras5, James W Krieger6, Michael G Miller7, Jason Cholewa8. 1. Institute of Bioscience, Department of Physical Education, São Paulo State University, Rio Claro, Brazil. 2. Department of Kinesiology, Coastal Carolina University, Conway, SC, USA. 3. Department of Health Sciences, CUNY Lehman College, Bronx, NY, USA. 4. Kinesiology Program, Arizona State University, Phoenix, AZ, USA. 5. Sport Performance Research Institute, AUT University, Auckland, New Zealand. 6. Weightology, LLC, Issaquah, WA, USA. 7. Department of Human Performance and Health Education, Western Michigan University, Kalamazoo, MI, USA. 8. Department of Kinesiology, Coastal Carolina University, Conway, SC, USA - jcholewa@coastal.edu.
Abstract
BACKGROUND: The purpose of this study was to compare strength, body composition, and functional outcome measures following performance of the back squat, leg press, or a combination of the two exercises. METHODS: Subjects were pair-matched based on initial strength levels and then randomly assigned to 1 of 3 groups: a squat-only group (SQ) that solely performed squats for the lower body; a leg press-only group (LP) that solely performed leg presses for the lower body, or a combined squat and leg press group (SQ-LP) that performed both squats and leg presses for the lower body. All other RT variables were held constant. The study period lasted 10 weeks with subjects performing 2 lower body workouts per week comprising 6 sets per session at loads corresponding to 8-12 RM with 90- to 120-second rest intervals. RESULTS: Results showed that SQ had greater transfer to maximal squat strength compared to the leg press. Effect sizes favored SQ and SQ-LP versus LP with respect to countermovement jump while greater effect sizes for dynamic balance were noted for SQ-LP and LP compared to SQ, although no statistical differences were noted between conditions. CONCLUSIONS: These findings suggest that both free weights and machines can improve functional outcomes, and that the extent of transfer may be specific to the given task.
RCT Entities:
BACKGROUND: The purpose of this study was to compare strength, body composition, and functional outcome measures following performance of the back squat, leg press, or a combination of the two exercises. METHODS: Subjects were pair-matched based on initial strength levels and then randomly assigned to 1 of 3 groups: a squat-only group (SQ) that solely performed squats for the lower body; a leg press-only group (LP) that solely performed leg presses for the lower body, or a combined squat and leg press group (SQ-LP) that performed both squats and leg presses for the lower body. All other RT variables were held constant. The study period lasted 10 weeks with subjects performing 2 lower body workouts per week comprising 6 sets per session at loads corresponding to 8-12 RM with 90- to 120-second rest intervals. RESULTS: Results showed that SQ had greater transfer to maximal squat strength compared to the leg press. Effect sizes favored SQ and SQ-LP versus LP with respect to countermovement jump while greater effect sizes for dynamic balance were noted for SQ-LP and LP compared to SQ, although no statistical differences were noted between conditions. CONCLUSIONS: These findings suggest that both free weights and machines can improve functional outcomes, and that the extent of transfer may be specific to the given task.
Authors: Neil A Schwarz; Sean P Harper; Andy Waldhelm; Sarah K McKinley-Barnard; Shelley L Holden; John E Kovaleski Journal: Sports (Basel) Date: 2019-09-30
Authors: James Steele; Patroklos Androulakis-Korakakis; Luke Carlson; David Williams; Stuart Phillips; Dave Smith; Brad J Schoenfeld; Jeremy P Loenneke; Richard Winett; Takashi Abe; Stéphane Dufour; Martino V Franchi; Fabio Sarto; Tommy R Lundberg; Paulo Gentil; Thue Kvorning; Jürgen Giessing; Milan Sedliak; Antonio Paoli; Fiona Spotswood; Alex Lucas; James P Fisher Journal: Sports Med Date: 2021-04-19 Impact factor: 11.136