Exercise strategies to protect against the impact of short-term reduced physical activity on muscle function and markers of health in older men: study protocol for a randomised controlled trial

Abstract

BackgroundMuscles get smaller and weaker as we age and become more vulnerable to atrophy when physical activity is reduced or removed. This research is designed to investigate the potentially protective effects of two separate exercise strategies against loss in skeletal muscle function and size, and other key indices of health, following 14 days of reduced physical activity in older men.MethodsThree groups of 10 older men (aged 65–80 years) will undertake 2 weeks of reduced activity by decreasing daily steps from more than 3500 to less than 1500 (using pedometers to record step count). Two of the three groups will then undertake additional exercise interventions, either: 4 weeks of progressive resistance training prior to the step-reduction intervention (PT-group), or home-based ‘exercise snacking’ three times per day during the step-reduction intervention (ES-group). The third group undertaking only the step-reduction intervention (control) will provide a comparison against which to assess the effectiveness of the protective exercise strategies. Pre and post step-reduction assessments of muscle function, standing balance, anthropometry and muscle architecture will be taken. Pre and post step-reduction in postprandial metabolic control, resting systemic inflammation, adipose inflammation, oxidative stress, immune function, sleep quality, dietary habits, and quality of life will be measured. The stress response to exercise, and signalling protein and gene expression for muscle protein synthesis and breakdown following an acute bout of exercise will also be assessed pre and post step-reduction. Rates of muscle protein synthesis and adipose triglyceride turnover during the step-reduction intervention will be measured using stable isotope methodology. All participants will then undertake 2 weeks of supervised resistance training with the aim of regaining any deficit from baseline in muscle function and size.DiscussionThis study aims to identify exercise strategies that could be implemented to protect against loss of muscle power during 2 weeks of reduced activity in older men, and to improve understanding of the way in which a short-term reduction in physical activity impacts upon muscle function and health.Trial registrationClinicalTrials.gov: NCT02495727 (Initial registration: 25 June 2015)

Meal-exercise challenge and physical activity reduction impact on immunity and inflammation (MERIIT trial)

“…Nevertheless, this is, to our knowledge, the largest trial evaluating the reduction of physical activity on immunological, inflammatory and allostatic load. Recently a trial protocol was published that proposes to evaluate the usefulness of specific exercise strategies during a step-reduction, but in an older population and using as a primary outcome the muscle function and size [ 77 ]. The high attrition rate was probably correlated to the included population, particularly individuals which were “low active”.…”

Reduced physical activity in young and older adults: metabolic and musculoskeletal implications

“…A two-part schematic representing the Catabolic Crisis model proposed by English and Paddon-Jones 47 (upper figure) and the reduced activity models (young versus old) proposed by Perkin and colleagues 48 (lower figure).…”

“…Studies looking at different types of concomitant exercise during periods of step reduction in older men (resistance training prior to step reduction, exercise three times per day during the step-reduction period and a control) are also under way. 48…”

Effects of Exergaming on Balance of Healthy Older Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials

“…14,15 Standard balance exercise protocols based on functional activities and progressive resistance training have been applied to clinical rehabilitation. [16][17][18] However, adherence to exercise programs is challenging, because exercise programs are often considered monotonous and boring. 19,20 Loss of interest is a common reason for discontinuation of regular exercise programs among clients.…”