Kanarek Robin B, D'Anci Kristen E, Jurdak Nicole, Mathes Wendy Foulds
Department of Psychology, Tufts University, 490 Boston Avenue, Medford, MA 02155, USA.
Behav Neurosci. 2009 Aug;123(4):905-12. doi: 10.1037/a0015896.
Exercise improves cardiovascular health, strengthens muscles and bones, stimulates neuroplasticity, and promotes feelings of well-being. However, when taken to extremes, exercise can develop into an addictive-like behavior. To assess the addictive potential of exercise, withdrawal symptoms following injections of 1.0 mg/kg naloxone were compared in active and inactive male and female rats. Active and inactive rats were given food for 1 hr or 24 hr/day. Additionally, a group of inactive rats was pair-fed the amount of food consumed on the previous day by food-restricted active rats. Rats fed for 1 hr/day decreased food intake and lost weight. Additionally, food-restricted active rats increased wheel running. There was a direct relationship between the intensity of running and the severity of withdrawal symptoms. Active food-restricted rats displayed the most withdrawal symptoms, followed by active rats given 24-hr access to food. Only minimal withdrawal symptoms were observed in inactive rats. These findings support the hypothesis that exercise-induced increases in endogenous opioid peptides act in a manner similar to chronic administration of opiate drugs.
运动有益于心血管健康，能增强肌肉和骨骼，刺激神经可塑性，并提升幸福感。然而，若走向极端，运动可能会发展成类似成瘾的行为。为评估运动的成瘾潜力，研究人员比较了注射1.0毫克/千克纳洛酮后，活跃和不活跃的雄性及雌性大鼠的戒断症状。活跃和不活跃的大鼠分别被给予每天1小时或24小时的进食时间。此外，一组不活跃的大鼠被配对喂食前一天食物受限的活跃大鼠所消耗的食物量。每天仅喂食1小时的大鼠食物摄入量减少且体重减轻。此外，食物受限的活跃大鼠增加了转轮跑步的量。跑步强度与戒断症状的严重程度之间存在直接关系。食物受限的活跃大鼠表现出最严重的戒断症状，其次是每天有24小时进食机会的活跃大鼠。在不活跃的大鼠中仅观察到极少的戒断症状。这些发现支持了这样一种假设，即运动引起的内源性阿片肽增加，其作用方式类似于长期使用阿片类药物。
