Comparing Different Intensities of Acute Exercise on State Anxiety in MS: A Randomized Controlled Study

Background: Previous research suggests a beneficial change in mood from before to after a single bout of exercise in MS. However, there are limited data comparing the effects of different intensities of acute exercise with a true control condition (i.e. sitting on the ergometer without cycling) on mood states in individuals with relapsing remitting multiple sclerosis (RRMS).

Objectives: The present study investigated the effect of acute exercise on state anxiety immediately and 1-hour after 10-minute bouts of moderate and high intensity cycling and a true control.

Methods: The study used a complete within-subjects design. All participants (N=16, Age=51.58) had RRMS (EDSS = 1.5-4.5) and completed 3 conditions delivered in a randomized order with 1 week between conditions. The 3 conditions included 10-minutes of moderate (40% peak oxygen consumption) or high (60% peak oxygen consumption) intensity cycle ergometry as well as a true control of sitting on the ergometer for 10 minutes. This was followed by 1-hour of seated rest in a comfortable chair located in the laboratory for documenting prolonged change in anxiety. Participants completed the abbreviated, 6-item State Anxiety Inventory (SAI) immediately before and after and 1-hour after each condition.

Results: Multivariate analysis on SAI scores indicated a statistically significant condition by time interaction (p<0.05) on SAI scores. There was an immediate reduction in SAI scores after the 2 exercise condition, but not control condition. The reduction was sustained at 1-hour after completion of the high intensity, but not moderate intensity, exercise condition.

Conclusions: These findings suggest that acute bouts of exercise might be associated with reductions in state anxiety in persons with RRMS and the duration of these effects might depend on the intensity of exercise.