Sandroff Brian M, Hillman Charles H, Benedict Ralph H B, Motl Robert W
Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Louise Freer Hall, 906 S. Goodwin Ave, Urbana, IL 61801, USA.
Department of Neurology, University at Buffalo, State University of New York, 100 High St., Buffalo, NY 14203, USA.
Physiol Behav. 2016 Feb 1;154:20-7. doi: 10.1016/j.physbeh.2015.11.008. Epub 2015 Nov 10.
Exercise training represents a promising approach for managing cognitive impairment in persons with multiple sclerosis (MS). There is preliminary evidence that treadmill walking might be the modality of exercise that exerts the greatest beneficial effects on inhibitory control in fully-ambulatory persons with MS. However, the dose-dependent effects of varying intensities of treadmill walking exercise on this cognitive function are unknown. Such an investigation is critical for better delineating the optimal exercise stimulus (or stimuli) for improving inhibitory control in MS.
The present study compared the acute effects of light, moderate, and vigorous intensity treadmill walking exercise on inhibitory control (i.e., interference control) relative to quiet rest in 24 fully-ambulatory persons with MS, using a within-subjects, repeated-measures experimental design. Participants completed four experimental conditions that consisted of 20min of light, moderate, and vigorous intensity treadmill walking exercise, and quiet rest in a randomized, counterbalanced order. Participants underwent a modified flanker task as a measure of inhibitory control immediately prior to and following each condition.
Repeated-measures ANOVAs indicated large, statistically significant reductions in the cost of interfering stimuli on reaction time, but not accuracy, on the modified flanker task for light, moderate, and vigorous intensity exercise compared with quiet rest (F(3,69)=4.27, p=.01, ηp(2)=.16). There were no differences in magnitude of reduction across the three exercise intensities.
The present results support light, moderate, and vigorous intensity treadmill walking as exercise stimuli that might particularly benefit interference control of reaction time. This represents the next step in delineating the optimal exercise stimuli for improving this cognitive function in fully-ambulatory persons with MS, and perhaps is important for informing a subsequent longitudinal exercise training intervention.
运动训练是管理多发性硬化症（MS）患者认知障碍的一种有前景的方法。有初步证据表明，对于能够完全行走的MS患者，跑步机行走可能是对抑制控制产生最大有益影响的运动方式。然而，不同强度的跑步机行走运动对这种认知功能的剂量依赖性影响尚不清楚。这样的研究对于更好地确定改善MS患者抑制控制的最佳运动刺激至关重要。
本研究采用受试者内重复测量实验设计，比较了24名能够完全行走的MS患者在进行轻度、中度和剧烈强度的跑步机行走运动与安静休息时对抑制控制（即干扰控制）的急性影响。参与者以随机、平衡的顺序完成四个实验条件，包括20分钟的轻度、中度和剧烈强度的跑步机行走运动以及安静休息。在每个条件之前和之后，参与者接受改良的侧翼任务作为抑制控制的测量。
重复测量方差分析表明，与安静休息相比，轻度、中度和剧烈强度运动在改良侧翼任务上干扰刺激对反应时间的成本有大幅且具有统计学意义的降低，但对准确性没有影响（F(3,69)=4.27，p=.01，ηp(2)=.16）。三种运动强度的降低幅度没有差异。
本研究结果支持轻度、中度和剧烈强度的跑步机行走作为运动刺激，可能对反应时间的干扰控制特别有益。这是确定改善能够完全行走的MS患者这种认知功能的最佳运动刺激的下一步，也许对于后续的纵向运动训练干预具有重要意义。
