Author(s): HARROUM, N., PAGEAUX, B., NEVA, J.L., Institution: UNIVERSITÉ DE MONTRÉAL, Country: CANADA, Abstract-ID: 2464

INTRODUCTION:
In daily life, we are required to learn new motor skills and to adapt our movements to changes in our environment. This dynamic process of adjusting to changes in our environment is known as “motor adaptation” and constitutes an important category of motor learning. Studies have shown that a single session of aerobic exercise (AE) can enhance motor adaptation compared to rest. Specifically, high intensity AE can increase motor adaptation, while moderate intensity AE has been shown to both enhance motor adaptation and to have no effect. No studies have investigated the impact of low intensity AE on motor adaptation. Hence, it is still unclear how the intensity of AE influences motor adaptation.
This study aimed to investigate the dose-response effect of AE intensity on motor adaptation while controlling for other AE exercise parameters (duration, type) in young adults. We hypothesized that moderate and high AE intensity would lead to greater motor adaptation compared to rest.
METHODS:
Eighty healthy young adults (18–39 years) were divided into four groups (n=20/group): 20 min of interval AE training at high-intensity (HIIT), moderate-intensity (MIIT), low-intensity (LIIT), or Rest (control). A visit prior to the intervention was conducted to perform an incremental cycling test to assess cardiorespiratory capacity. Heart rate reserve (HRR) was used to prescribe the AE intensity for visit 2. AE consisted of four blocks of 3-min cycling on an ergometer (LIIT, 35%HRR; MIIT, 55%HRR; HIIT, 80%HRR), interspersed with 2 min of active recovery (25%HRR). Perceptual responses (effort, muscle pain and affects) were reported during AE/Rest sessions. Participants completed a visuomotor rotation task (45°) immediately (acquisition: motor adaptation) and 24-h (retention test: motor learning) after AE/Rest. Performance was assessed using spatial (e.g., angle at peak velocity) and temporal (e.g., reaction time) metrics.
RESULTS:
The results revealed a dose-response effect of AE intensity on motor adaptation and learning. HIIT and MIIT increased motor learning more than LIIT and Rest (temporal and spatial metrics). HIIT showed the greatest motor adaptation (temporal and spatial metrics), followed by MIIT, then LIIT (temporal metrics). Findings showed that the lower the AE intensity, the more positive perceptual responses (e.g., less muscle pain, lower perception of effort).
CONCLUSION:
This research is the first to reveal a dose-response effect of AE intensity on motor learning. Specifically, the higher the AE intensity, the larger the improvements in motor adaptation and learning. These findings suggest that exercise intensity prescription could be a key factor in tailoring training protocols for athletes to enhance motor skills and adapt to varying dynamics in sport. Since MIIT elicited more favorable perceptual responses than HIIT, clinicians may consider MIIT as a viable alternative for individuals who may be more impacted by the negative perceptual responses associated with HIIT.