Core self-evaluation as a predictor of strength training adoption in older adults

Study protocol for the BRAIN Training Trial: a randomised controlled trial of Balance, Resistance, And INterval training on cognitive function in older adults with mild cognitive impairment

INTRODUCTION

Epidemiological evidence suggests that both poor cardiovascular fitness and low muscle mass or strength markedly increase the rate of cognitive decline and incident dementia in older adults. Results from exercise trials for the improvement of cognition in older adults with mild cognitive impairment (MCI) have reported mixed results. This is possibly due to insufficient exercise intensities. The aim of the Balance, Resistance, And INterval (BRAIN) Training Trial is to determine the effects of two forms of exercise, high-intensity aerobic interval training (HIIT) and high-intensity power training (POWER) each compared with a sham exercise control group on cognition in older adults with MCI.

METHODS AND ANALYSIS

One hundred and sixty community-dwelling older (≥ 60 years) people with MCI have been randomised into the trial. Interventions are delivered supervised 2-3 days per week for 12 months. The primary outcome measured at baseline, 6 and 12 months is performance on a cognitive composite score measuring the executive domain calculated from a combination of computerised (NeuroTrax) and paper-and-pencil tests. Analyses will be performed via repeated measures linear mixed models and generalised linear mixed models of baseline, 6-month and 12-month time points, adjusted for baseline values and covariates selected a priori. Mixed models will be constructed to determine the interaction of GROUP × TIME.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of Sydney (HREC Ref.2017/368), University of Queensland (HREC Ref. 2017/HE000853), University of British Columbia (H16-03309), and Vancouver Coastal Health Research Institute (V16-03309) Human Research Ethics. Dissemination will be via publications, conference presentations, newsletter articles, social media, talks to clinicians and consumers and meetings with health departments/managers.It is expected that communication of results will allow for the development of more effective evidence-based exercise prescription guidelines in this population while investigating the benefits of HIIT and POWER on subclinical markers of disease.

TRIAL REGISTRATION NUMBER

ACTRN12617001440314 Australian New Zealand Clinical Trials Registry.

Sex Difference in Participation in Muscle-Strengthening Activities

Background

Previous data from the United States Centers for Disease Control and Prevention indicate men are more likely than women to participate in muscle-strengthening activities (e.g., resistance training). However, a recent review by Rhodes et al. concluded there is no reliable sex difference in participation. The purpose of the current paper was to review population-level surveys of participation in muscle-strengthening activities to clarify if a sex difference in participation exists.

Methods

Keyword searches (e.g., "resistance training participation") were performed in PubMed and Google Scholar to identify papers that surveyed a general adult population (N > 1,000) and reported an outcome of the proportion of the population meeting recommendations for "muscle-strengthening activities" (i.e., ≥ 2 times/wk) or participating in resistance training.

Results

Sixteen studies from 6 countries met the inclusion criteria. Irrespective of the measure of participation, population-levels of participation were typically higher in men than women. More men than women met recommendations for muscle-strengthening activities in England (men 34%; women 24%), Finland (men 18.1%; women 16.4%), Northern Ireland (men 25%; women 14%), Scotland (men 30%; women 25%), and the United States (men 34.8%; women 25.8%). For Australia, some studies showed no sex difference in participation, whereas other studies showed greater participation among men.

Conclusion

A sex difference exists in participation in muscle-strengthening activities. Low participation rates in both sexes indicate efforts to encourage participation in men and women are warranted. The results also highlight the need for rigorous definitions of "participation," as the lack of such definitions explains the mixed results reported previously.