Neuromuscular recovery after a strength training session in elderly people

Abstract

Ageing is associated with an increased susceptibility to muscle damage but little is known on how this affects muscle recovery after exercise. Hence, this study is aiming at investigating the effects of a heavy-resistance training session of neuromuscular recovery of the calf muscles of a group of elderly men aged >65. Maximal isometric and isokinetic torque, muscle voluntary activation (VA) capacity, surface electromyographic activity (EMG), peak-to-peak amplitude of action potentials associated with twitch responses of plantar flexors were evaluated before and 5 min (post1), 24 h (post2) and 48 h (post3) after 10 sets of 10 repetitions of a calf raise exercise performed at an intensity of 70% of the individual, one repetition maximum. Blood samples were taken before and 1, 48, 96 and 144 h after the training session and assayed for serum creatine kinase (CK), lactate dehydrogenase (LDH) and myoglobin (Mb). Peak torque during eccentric and concentric (120 degrees s-1) contractions and twitch parameters were significantly reduced at post1, and recovered completely at post2. No significant changes were found in integrated EMG, M-wave amplitudes and VA throughout the entire test period. CK and LDH concentrations reached peak values 48 h after the exercise session and returned to the pre-exercise values 96 h after the training session. Serum Mb level increased by 73.2% 1 h after exercise and recovered at 48 h. The reduction in peak torque following a strength training session in an elderly population could be explained mainly by fatigue of peripheral origin. After 24 h the elders recovered completely their capacities of strength production, despite muscle damage being still evident 48 h after the strength training session.

Espessura e qualidade musculares medidas a partir de ultrassonografia: influência de diferentes locais de mensuração. DOI: 10.5007/1980-0037.2011v13n2p87

“…20,21 . Posteriormente, vários estudos utilizaram imagens obtidas por ultrassonografia 11,18,22 , ressonância magnética 8 e tomografia computadorizada 23 para análise das adaptações morfológicas. Especificamente, tratando-se da mensuração da EM por ultrassonografia, tem-se utilizado diferentes pontos de medida 10,17 .…”

Age‐related reductions in the estimated numbers of motor units are minimal in the human soleus

“…In contrast, the old men were only able to activate to 88%, a finding in keeping with recent plantar-flexor studies on older populations. 20,33,43 Due in part to the submaximal activation in the old, there was a decrease in plantar-flexor maximal voluntary strength with age. These results mirror those of Vandervoort and McComas 46 and are also quite similar to other, more recent studies.…”

Age-Related Changes in Neuromuscular Function and Performance following a High-Intensity Intermittent Task in Endurance-Trained Men

“…One-repetition maximum values were obtained during the familiarization session the week before using standard procedures [29] . The rest between the sets was 90 s. The exercise consisted of a 3-second concentric contraction followed by a 3-second eccentric contraction.…”

“…This is particularly the case during long-distance events where a significant decrease in muscular performance is systematically described with exercise duration [28] . More recently, many studies have investigated neuromuscular function with fatigue using electromyography (EMG) and electrical stimulation techniques [21,23,29,30] . These noninvasive techniques use the measurements of M-wave, twitch amplitude and twitch duration to better characterize the origin of neuromuscular fatigue (i.e., central and/or peripheral fatigue) [31] .…”