Effects of isokinetic eccentric versus traditional lower body resistance training on muscle function: examining a multiple-joint short-term training model

Abstract

Early adaptations of eccentric training show several advantages over concentric training. The purpose of this study was to quantify the effects of 4-weeks of multi-joint eccentric versus traditional leg press (TLP) training on muscle strength, rate of torque development (RTD) and jump and sprint performance adaptations. Twenty-six resistance trained adults performed either an eccentric or a TLP resistance training program twice per week for 4-weeks. Single-joint isometric maximum and rapid strength (peak torque and RTD, respectively) and isokinetic strength of the knee extensors and flexors, multi-joint eccentric strength, leg press strength (1-RM), 40-m sprint, and vertical and long jump were measured before (Pre), at the midpoint (Mid), and after (Post) a 4-week training period. Four weeks of isokinetic multi-joint eccentric training elicited greater test-specific strength gains (ES=1.06) compared to TLP (ES=0.11). The eccentric group (ES=0.51 and 0.54) also yielded moderate improvements in the early-middle phase RTD (RTD100-200) whereas the TLP group showed small-moderate improvements (ES=0.37). The majority of the single-joint strength variables showed negligible improvements. Performance tests showed no (broad jump) to small (vertical jump; sprint for the leg press) improvements. Eccentric multi-joint training induced significant improvements for lower body strength in a short amount of time in a trained population. These accelerated adaptations and also the lowered energy requirements of eccentric exercise may be useful for clinicians or practitioners when prescribing training programs for those who are injured, sedentary, or elderly, who are in need of time efficient muscle function improvements.

Comparison of High Versus Low Eccentric-Based Resistance Training Frequencies on Short-Term Muscle Function Adaptations

“…The training program followed an intensity progression that has been previously used for Eccentron dynamometer training (12) and was initially developed from pilot work. Specifically, intensity was the only variable involved in the progression and represents the percentage of the baseline maximum eccentric strength.…”

“…Strength Testing. Subjects were seated on an isokinetic dynamometer (Eccentron; BTE Technologies, Inc., Hanover, MD) and adjusted to a position that placed the knee joint at 30°in the most extended position per the manufacturer's recommendation (12). Subjects performed 6 eccentric MVCs for each leg, alternating legs every other repetition in a consecutive manner.…”

Potential Benefits of a Minimal Dose Eccentric Resistance Training Paradigm to Combat Sarcopenia and Age-Related Muscle and Physical Function Deficits in Older Adults

“…The vast majority of previous studies examining eccentric RT have implemented a moderate or high intensity training routine (using our definition of >50% of maximal eccentric strength and/or ≥12 on the Borg scale) ( LaStayo et al, 2003 , 2007 , 2011 , 2017 ; Dibble et al, 2006 ; Jacobs et al, 2014 ; Tanner et al, 2015 ; McKenzie et al, 2017 ; Suh et al, 2017 ; Briggs et al, 2018 ; Reidy et al, 2018 ; Gordon et al, 2019 ; Crane et al, 2020 ; Kumar, 2021 ). While the gains from these doses were indeed favorable, it is possible that such loads are more excessive than what is needed to elicit adaptations from eccentric RT since eccentric contractions inherently create high internal muscle-tendon forces, even without performing near maximal contractions ( Hody et al, 2019 ).…”

“…Exercise session durations for multi-joint eccentric training have varied considerably within the broad (all adult ages) literature from a more minimal dose (e.g., three/min sessions) ( Gordon et al, 2019 ; Crane et al, 2020 ) up to 30 min/sessions ( Dibble et al, 2006 ; Suh et al, 2017 ; Lim and Lee, 2018 ; Kim et al, 2019 ). While a three/min exercise session may represent a minimal training approach, this previous work was conducted in young adults ( Gordon et al, 2019 ; Crane et al, 2020 ). Thus, it is unknown how older adults will respond to a shorter duration exercise session.…”

Eccentric-only versus concentric-only resistance training effects on biochemical and physiological parameters in patients with type 2 diabetes

“…Previous eccentric exercise studies only used resistance exercise of an isolated single muscle group or aerobic mode of exercise as an intervention for patients with T2D [ 13 ]. To the best of our knowledge, no studies have investigated the effects of eccentric-only resistance training on insulin sensitivity, lipid profile, body composition, muscle strength and physical function in adults with T2D in comparison to concentric-only resistance training.…”