One, two, or three times a week? examining the optimal frequency for strength and muscle growth in accentuated eccentric exercise.

Abstract

Purpose: This study examines the effects of performing accentuated eccentric loading (AEL) resistance exercise one, two, or three times per week, with equal session doses, in resistance-trained athletes.

Methods: Twenty-three strength-trained athletes were allocated to one of three exercise groups: EX1 (n = 7), EX2 (n = 9), and EX3 (n = 7). Participants engaged in AEL full squat training once (EX1), twice (EX2), or three times (EX3) per week for 12 weeks. Maximum concentric (CONM), isometric (ISOM), and eccentric strength (ECCM), and strength endurance (SE70), were assessed using the full squat. Muscular power was evaluated through squat jump (SJ) and countermovement jump (CMJ) tests. Muscle cross-sectional area (CSA) was measured via computed tomography, and muscle fiber type proportions by mATP-ase histochemistry.

Results: Across all groups, ISOM (9.1 ± 8.5%), CONM (9.3 ± 5.7%), ECCM (14.0 ± 6.7%), and SE70 (28.6 ± 16.2%) increased significantly (all P < 0.001). SJ improved by 7.3 ± 6.9% (P < 0.001), and CMJ improved by 4.4 ± 6.0% (P = 0.003). Quadriceps CSA increased by 3.6 ± 4.1% (P < 0.001), and thigh CSA increased by 2.1 ± 2.9% (P = 0.005). The only significant between-group difference was that EX3 exhibited a greater increase in CONM compared with EX1 (P = 0.03).

Conclusion: Training with AEL resistance exercise one, two, or three times per week for 12 weeks produced similar effects on maximum strength, power, and hypertrophy in resistance-trained athletes.