ORIGINAL ARTICLE  BODY COMPOSITION, NUTRITION AND SUPPLEMENTATION 

The Journal of Sports Medicine and Physical Fitness 2018 March;58(3):263-70

DOI: 10.23736/S0022-4707.16.06698-6

Copyright © 2016 EDIZIONI MINERVA MEDICA

language: English

Strength, body composition, and functional outcomes in the squat versus leg press exercises

Fabrício E. ROSSI ^{1, 2}, Brad J. SCHOENFELD ³, Skyler OCETNIK ¹, Jonathan YOUNG ¹, Andrew VIGOTSKY ⁴, Bret CONTRERAS ⁵, James W. KRIEGER ⁶, Michael G. MILLER ⁷, Jason CHOLEWA ² ✉

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

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.

KEY WORDS: Physical fitness - Resistance training - Exercise