Impact of Wearable Acceleration-Monitored Simulated Vigorous Intermittent Lifestyle Physical Activity on Muscle Strength in Young Adults

Background The benefits of sustained structured physical activity for general health have been widely investigated. Current guidelines also recognize the research potential of short bouts of activity. The aim of this study was to investigate the effects of a simulated vigorous intermittent lifestyle physical activity (VILPA) intervention monitored by wearable devices on lower limb muscle strength. Methods Totally, 40 healthy sedentary college-age students were recruited to wear accelerometry for a prolonged period of time and undergo an eight-week simulated VILPA intervention using a single-arm pre-post design. Demographic information and blood lipids were collected before and after the intervention. Muscle strength was measured by isokinetic muscle strength testing and surface electromyography. Finally, 35 participants completed the study. Results The mean age of the participants was 19.9 ± 1.1 years. After the simulated VILPA intervention, participants experienced significant increases in weight, body mass index, body fat percentage, waist circumference, and triglyceride levels. Additionally, there were significant improvements in peak torque and peak torque normalized to body weight for bilateral ankle dorsiflexor and plantarflexor muscle groups post-intervention. The surface electromyography examinations revealed significant increases in root mean square (RMS) and average electromyography (AEMG) values for all three calf muscle groups (anterior tibialis, gastrocnemius, and soleus) post-intervention, although parameters for the gastrocnemius muscle were significantly different only in the right calf. Conclusion Three bouts of VILPA per day enhance calf muscle strength in healthy populations. VILPA appears to be suitable for non-exercisers as a timesaving and potentially effective intervention measure.