Muscles adaptation to aging and training: architectural changes – a randomised trial

Abstract Background To investigate how anatomical cross-sectional area and volume of quadriceps triceps surae muscles were affected by ageing, resistance training in older younger men, vivo. Methods The old participants randomly assigned to moderate (O55, n = 13) or high-load (O80, 14) intervention (12 weeks; 3 times/week) corresponding 55% 80% one repetition maximum, respectively. Young men (Y55, 11) the moderate-intensity strengthening exercise program. Each group received exact same on (Reps x Sets Intensity). fitting polynomial regression equations for each area-muscle length curves used calculate muscle (contractile content) before after 12 weeks using magnetic resonance imaging scans. Results Only Rectus femoris medial gastrocnemius showed a higher relative young than elderly proximal end. displayed absolute non-contractile material (+ 96%). After training, Y55, O55 O80 an increase total 4.3%; + 6.7%; 4.2% respectively) 2.8%; 7.5%; 4.3% volume. demonstrated greater average gains compared while no difference between was observed. Conclusions Muscle loss with aging is region-specific some uniform others. Equivalent strength at high intensities increased differences men. These data suggest that physical intensity (55 60% maximum) can reverse related mass. Trial registration NCT03079180 ClinicalTrials.gov . Registration date: March 14, 2017.