Older people who have never taken part in sustained exercise programmes have the same ability to build muscle mass as highly trained master athletes of a similar age, according to research at the University of Birmingham. The research shows that even those who are entirely unaccustomed to exercise can benefit from resistance exercises such as weight training.
In the study, researchers in the University of Birmingham's School of Sport and Exercise Science compared muscle-building ability in two groups of older men. The first group were classed as 'master athletes' – people in their 70s and 80s who are lifelong exercisers and still competing at top levels in their sport. In the second were healthy individuals of a similar age, who had never participated in structured exercise programmes.
Each participant was given an isotope tracer, in the form of a drink of 'heavy' water, and then took part in a single bout of exercise, involving weight training on an exercise machine. The researchers took muscle biopsies from participants in the 48-hour periods just before and just after the exercise, and examined these to look for signs of how the muscles were responding to the exercise. The isotope tracer showed how proteins were developing within the muscle.
The researchers had expected that the master athletes would have an increased ability to build muscle due to their superior levels of fitness over a prolonged period of time. In fact, the results showed that both groups had an equal capacity to build muscle in response to exercise.
"Our study clearly shows that it doesn't matter if you haven't been a regular exerciser throughout your life, you can still derive benefit from exercise whenever you start," says lead researcher, Dr Leigh Breen. "Obviously a long-term commitment to good health and exercise is the best approach to achieve whole-body health, but even starting later on in life will help delay age-related frailty and muscle weakness.
"Current public health advice on strength training for older people is often quite vague. What's needed is more specific guidance on how individuals can improve their muscle strength, even outside of a gym-setting through activities undertaken in their homes – activities such as gardening, walking up and down stairs, or lifting up a shopping bag can all help if undertaken as part of a regular exercise regime."
Background: An impaired muscle anabolic response to exercise and protein nutrition is thought to underpin age-related muscle loss, which may be exacerbated by aspects of biological aging that may not be present in older individuals who have undertaken long-term high-level exercise training, or master athletes (MA). The aim of this study was to compare rested-state and exercise-induced rates of integrated myofibrillar protein synthesis (iMyoPS) and intracellular signaling in endurance trained MA and healthy age-matched untrained individuals (Older Controls).
Methods: In a parallel study design, iMyoPS rates were determined over 48 h in the rested-state and following a bout of unaccustomed resistance exercise (RE) in OC (n = 8 males; 73.5 ± 3.3 years) and endurance-trained MA (n = 7 males; 68.9 ± 5.7 years). Intramuscular anabolic signaling was also determined. During the iMyoPS measurement period, physical activity was monitored via accelerometry and dietary intake was controlled.
Results: Anthropometrics, habitual activity, and dietary intake were similar between groups. There was no difference in rested-state rates of iMyoPS between OC (1.47 ± 0.06%⋅day–1) and MA (1.46 ± 0.08%⋅day–1). RE significantly increased iMyoPS above rest in both OC (1.60 ± 0.08%⋅day–1, P < 0.01) and MA (1.61 ± 0.08%⋅day–1, P < 0.01), with no difference between groups. AktThr308 phosphorylation increased at 1 h post-RE in OC (P < 0.05), but not MA. No other between-group differences in intramuscular signaling were apparent at any time-point.
Conclusion: While our sample size is limited, these data suggest that rested-state and RE-induced iMyoPS are indistinguishable between MA and OC. Importantly, the OC retain a capacity for RE-induced stimulation of skeletal muscle remodeling.
James McKendry, Brandon J Shad, Benoit Smeuninx, Sara Y Oikawa, Gareth Wallis, Carolyn Greig, Stuart M Phillips, Leigh Breen
[link url="https://www.birmingham.ac.uk/news/latest/2019/08/never-too-late-to-start-exercising-new-study-shows.aspx"]University of Birmingham material[/link]
[link url="https://www.frontiersin.org/articles/10.3389/fphys.2019.01084/full"]Frontiers in Physiology abstract[/link]