Examining Unilateral and Bilateral Exercises through the Load-velocity Relationship

• Published in: International journal of sports medicine Vol. 45; no. 1; p. 41
• Main Authors: Martínez-Rubio, Carlos, Baena-Raya, Andrés, Díez-Fernández, David M, Rodríguez-Pérez, Manuel Antonio, Pareja-Blanco, Fernando
• Format: Journal Article
• Language: English
• Published: Germany 01.01.2024
• Subjects: Adult; Exercise; Exercise Therapy; Humans; Male; Muscle Strength; Muscle, Skeletal; Resistance Training; Weight Lifting; Young Adult
• ISSN: 1439-3964
• DOI: 10.1055/a-2151-0661

This study aimed to examine the load-velocity (L-V) relationship in the bench-press (BP) and leg-press (LP) exercises performed unilaterally, and compared this unilateral L-V relationship with the bilateral variants. Nineteen men (age=23.5±2.1 years) completed two incremental tests in BP and LP, performed bilaterally and unilaterally, across two sessions with a 48-hour rest period. We found a close relationship between medium propulsive velocity (MPV) and %1RM in unilateral BP (R  =0.97, SEE=0.06 m·s ) and LP (R =0.96, SEE=0.06 m·s ). No significant differences were observed between the preferred and non-preferred sides in the L-V relationship for either exercise. Additionally, higher velocities were achieved in unilateral exercises compared to bilateral exercises, particularly with light and moderate loads (30-70%1RM) in BP (p<0.05) and with light loads (30-45%1RM) in LP (p<0.05). Close L-V relationships were observed in unilateral exercises, without differences in the L-V relationships between preferred and non-preferred sides despite the interlimb asymmetries in the absolute strength values. Interestingly, lower velocities were observed at light loads (~30-45% 1RM) for bilateral compared to unilateral exercises, which could be explained by different strength deficits for these exercises.