The metabolic effects of habitual leg shaking: A randomized crossover trial

AimsThe adverse effects of sedentary behavior on obesity and chronic diseases are well established. However, the prevalence of sedentary behavior has increased, with only a minority of individuals meeting the recommended physical activity guidelines. This study aimed to investigate whether habitual leg shaking, a behavior traditionally considered unfavorable, could serve as an effective strategy to improve energy metabolism.Materials and MethodsA randomized crossover study was conducted, involving 15 participants (mean [SD] age, 25.4 [3.6]; mean [SD] body mass index, 22 [3]; 7 women [46.7%]). The study design involved a randomized sequence of sitting and leg shaking conditions, with each condition lasting for 20 min. Energy expenditure, respiratory rate, oxygen saturation, and other relevant variables were measured during each condition.ResultsCompared to sitting, leg shaking significantly increased total energy expenditure [1.088 kj/min, 95% confidence interval, 0.69-1.487 kj/min], primarily through elevated carbohydrate oxidation. The average metabolic equivalent during leg shaking exhibited a significant increase from 1.5 to 1.8. Leg shaking also raised respiratory rate, minute ventilation, and blood oxygen saturation levels, while having no obvious impact on heart rate or blood pressure. Electromyography data confirmed predominant activation of lower leg muscles and without increased muscle fatigue. Intriguingly, a significant correlation was observed between the increased energy expenditure and both the frequency of leg shaking and the muscle mass of the legs.ConclusionsOur study provides evidence that habitual leg shaking can boost overall energy expenditure by approximately 16.3%. This simple and feasible approach offers a convenient way to enhance physical activity levels. imageConclusionsOur study provides evidence that habitual leg shaking can boost overall energy expenditure by approximately 16.3%. This simple and feasible approach offers a convenient way to enhance physical activity levels. image HighlightsPrevious research has established the detrimental effects of sedentary behavior on obesity and chronic diseases. Efforts to mitigate heightened sedentary behavior through measures such as promoting elevated physical activity or incorporating extended standing and exercise during sedentary intervals have faced challenges in implementation. Our study confirmed that habitual leg shaking effectively increased energy expenditure by approximately 16.3%, elevated the metabolic equivalent to a nonhealthy level, enhanced carbohydrate oxidation, improved blood oxygen saturation and minute ventilation, while avoiding additional cardiovascular burden. Leg shaking offers a simple and feasible approach to enhance physical activity without disrupting daily routines. image