Cognitive Performance during Aerobic Exercise: Do Exercise Modality and Fitness Level Matter?
Objectives: This pilot study examined cognitive performance before and during acute bouts of treadmill walking exercise, stationary cycling exercise, and seated quiet rest in 12 fully-ambulatory persons with MS with high or low aerobic fitness using a within-subjects, repeated-measures design.
Methods: Participants underwent a baseline incremental exercise test to exhaustion for measurement of aerobic fitness (i.e., VO2peak). Participants further completed three experimental conditions that consisted of 20 minutes of moderate-to-vigorous intensity treadmill walking exercise, moderate-to-vigorous intensity cycle ergometer exercise, and seated quiet rest in a randomized, counterbalanced order. Participants underwent the 3-second Paced Auditory Serial Addition Test (PASAT) as a measure of cognitive performance prior to and during each condition.
Results: Overall, there were not larger decreases in PASAT performance during treadmill walking (d=−0.25) than during cycle ergometry (d=−0.40) relative to quiet rest (F(2,20)=0.80, p=.46, ηp2=.07). However, decreases in PASAT performance were larger for those with lower aerobic fitness during treadmill walking exercise than cycle ergometry compared with quiet rest (F(2,20)=3.24, p=.06, ηp2=.24).
Conclusions: The present results provide preliminary data on a potential mechanism whereby a single bout of treadmill walking exercise might affect cognitive processing to a greater degree than stationary cycling exercise, particularly among those with MS who demonstrate low aerobic fitness. This highlights the importance of targeting those with low aerobic fitness in treadmill walking exercise training interventions for improving cognition in persons with MS, as improving aerobic fitness may be beneficial for reducing MS-related cognitive-motor interference.