Comparison of the effects of isokinetic strength training with eccentric overload versus traditional strength training: A randomized controlled trial

Abstract

Objective: The aim of this study was to compare the effects of isokinetic strength training with eccentric overload (ISTEO) using the 1080 Quantum Syncro (Quantum) versus traditional strength training (TST) on maximal strength and muscle hypertrophy in experienced lifters over a 10-week intervention period Methods: A total of 30 participant s were initially enrolled in this randomized controlled trial (RCT), with 21 subjects completing the study (12 in the TST group and 9 in the ISTEO group). The primary outcomes measured were 1RM bench press (BP), 1RM biceps curl (BC), and biceps brachii hypertrophy. Pre- and post-intervention assessments included standardized 1RM testing and ultrasound imaging to evaluate changes in muscle thickness. Participants in the ISTEO group trained with the Quantum, which allows for controlled eccentric overload, while the TST group used traditional free weights.

Results: Both training modalities significantly increased maximal strength. The ISTEO group showed an 11.49% increase in BP (p < 0.001) and an 8.80% increase in BC (p = 0.029). The TST group exhibited an 11.23% increase in BP (p < 0.001) and an 8.21% increase in BC (p < 0.001). No significant differences were observed between the groups for either BP or BC (p > 0.05). For muscle hypertrophy, the ISTEO group showed a 7.67% increase in biceps brachii muscle thickness, compared to a 2.32% increase in the TST group. However, these differences were not statistically significant.

Conclusion: Both ISTEO and TST effectively improve maximal strength and muscle hypertrophy. The findings suggest that isokinetic strength training with eccentric overload can effectively enhance muscle growth and strength gains.