A Short-Term Intervention of High-Intensity Exercise and Anodal-tDCS on Motor Learning in Middle-Aged Adults: An RCT

Clare Quinlan; Ben Rattray; Disa Pryor; Joseph M Northey; James Coxon; Nicolas Cherbuin; Sophie C Andrews

doi:10.3389/fnhum.2021.661079

A Short-Term Intervention of High-Intensity Exercise and Anodal-tDCS on Motor Learning in Middle-Aged Adults: An RCT

Front Hum Neurosci. 2021 Jun 16:15:661079. doi: 10.3389/fnhum.2021.661079. eCollection 2021.

Authors

Clare Quinlan^{1

2}, Ben Rattray^{1

2

3}, Disa Pryor², Joseph M Northey^{1

2

3}, James Coxon⁴, Nicolas Cherbuin³, Sophie C Andrews^{3

4

5

6}

Affiliations

¹ UC Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT, Australia.
² Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, Canberra, ACT, Australia.
³ Centre for Research on Ageing, Health and Wellbeing, Australian National University, Canberra, ACT, Australia.
⁴ Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia.
⁵ Neuroscience Research Australia, Randwick, NSW, Australia.
⁶ School of Psychology, University of New South Wales, Sydney, NSW, Australia.

Abstract

High-intensity exercise has enhanced motor learning in healthy young adults. Anodal-transcranial direct current stimulation (a-tDCS) may optimize these effects. This study aimed to determine the effects of a short-term high-intensity interval exercise intervention either with or without a-tDCS on the learning and retention of a novel motor task in middle-aged adults. Forty-two healthy middle-aged adults (age = 44.6 ± 6.3, female = 76%) were randomized into three groups: exercise and active a-tDCS, exercise and sham a-tDCS, and a non-exercise and sham a-tDCS control. Participants completed a baseline testing session, followed by three intervention sessions 48-h apart. The exercise groups completed 20-min of high-intensity exercise followed by a novel sequential visual isometric pinch task (SVIPT) while receiving 20-min of 1.5 mA a-tDCS, or sham tDCS. The control group completed 20-min of reading before receiving sham a-tDCS during the SVIPT. Learning was assessed by skill change within and between intervention sessions. Participants returned 5-7 days after the final intervention session and performed the SVIPT task to assess retention. All three groups showed evidence of learning on the SVIPT task. Neither group displayed enhanced overall learning or retention when compared to the control group. High-intensity exercise with or without a-tDCS did not improve learning or retention of a novel motor task in middle-aged adults. The methodological framework provides direction for future research to investigate the potential of differing exercise intensity effects on learning and retention.

Keywords: aerobic exercise; cognition; motor cortex; non-invasive brain stimulation; transcranial direct current stimulation.