Effects of once- versus twice-weekly multi-joint eccentric exercise on lower-limb muscle function and structure in older adults

Description

INTRODUCTION: Resistance training combats sarcopenia in older adults by improving both muscular size and strength, although poor adherence rates to the twice-weekly guidelines can limit its effectiveness [1]. However, the high-force low-metabolic cost nature of eccentric resistance training has demonstrated greater adherence and functional adaptations compared with traditional strength training, even by individuals with pre-existing health conditions [2]. Therefore, the present study examined the dose-response and temporal characteristics of eccentric resistance training by comparing the effects of once- and twice-weekly 12-week training on lower-limb muscle function and structure of older adults.

METHODS: Participants were randomly assigned to control (CON [n = 14]), once-weekly (G1X [n = 14]), or twice-weekly (G2X [n = 14]) experimental groups. Eccentric and isometric strength, rate of torque development (RTD), sit-to-stand (STS), vastus lateralis thickness, fascicle length and angle, and quadriceps femoris volume were measured at baseline (week 0), mid-training (week 7), and post-training (week 13). Training was performed unilaterally on an isokinetic stepper ergometer at 50% of maximal eccentric strength at 18 step/min for 7 and 9 min in weeks 1 and 2, respectively, then for 12 min at 24 step/min in weeks 3-12. Two-way mixed model ANOVAs were conducted to identify significant (P
RESULTS: Within G1X, one participant withdrew, whereas in G2X, two participants withdrew and one was not included in analyses due to low adherence (
CONCLUSION: Once-weekly eccentric resistance training elicited similar improvements in neuromuscular function and structure compared to twice-weekly training in older adults. Given the difficulty older adults (and other exercise intolerant populations) have adhering to twice-weekly strength training programmes, these findings have important implications for clinical exercise prescription where substantial improvements in lower-limb muscle function and structure can be attained following once-weekly eccentric training.

REFERENCES
1.Merom et al. (2012). Preventive Medicine. 55:613-617.
2.LaStayo et al. (2014). J Appl Physiol. 116:1426-1434.

Period	7 Jul 2023
Event title	28th Annual Congress of the European College of Sport Science (ECSS)
Event type	Conference
Location	Paris, FranceShow on map
Degree of Recognition	International