Effects of Resistance Training Frequency on Muscle Function Adaptations Using a Multiple-Joint Eccentric Training Model

Eccentric resistance training has been shown to be beneficial for improving multiple performance and health metrics. However, recommendations on eccentric training frequency have not been established. PURPOSE: To investigate the effects of volume-matched resistance training frequency comparing one versus three training days per week of isokinetic multiple-joint eccentric training on strength and lower body function adaptations during a 4-week training period. METHODS: Thirty recreationally-trained men and women were randomly assigned to either a high frequency (HF), three times per week, or low frequency (LF), once per week, training group for four weeks. A motor-driven isokinetic eccentric dynamometer was used for the training and testing. Eccentric strength and vertical jump (VJ) measures were taken at Pre, Mid (two weeks), and Post (four weeks) intervention. Soreness and ratings of perceived exertion (RPE) were taken throughout the training period. RESULTS: There was no significant group × trial interaction for eccentric strength or VJ. For eccentric strength, all trials were significantly different from each other. For VJ, there was a main effect for trial such that VJ increased from Pre to Post and Mid to Post but was not different between Pre and Mid. The HF reported significantly lower RPE and soreness compared to the LF condition. CONCLUSIONS: Both HF and LF protocols elicited large and rapid neuromuscular strength adaptations. Eccentric-based workload may be dispersed across the week to allow for reduced soreness and exertion levels without compromising neuromuscular adaptations. Some transfer to functional (VJ) task may also be observed, independent of training frequency.