Active adults have thicker peripheral muscles and diaphragm: A cross-sectional study

Background: The association between physical activity and muscle mass is well established; individuals with limited physical activity demonstrate reduced muscle mass. But how much is that difference in muscle thickness between different levels of physical activity? Aim: To understand this we conducted a cross-sectional study to associate physical activity and sitting time with the muscle thickness of the lower limb and diaphragm. Methods: The research's participants ranged in age from 18 to 35. Out of 91 patients, 30 were found to smoke routinely and 6 had a drinking history after questions concerning lifestyle factors including smoking and drinking were questioned. 74.7% of participants were employed and 25% were unemployed. Muscle thickness for the quadriceps (rectus femoris and vastus intermedialis), soleus, and diaphragm were determined via ultrasonography. Participants were divided into groups according to their self-reported levels of physical activity and sitting time based on IPAQ scores. Results: We found that the lower limb muscles have shown statistically significant differences between vigorous physical activity (VPA) and lower physical activity (LPA). We found that the quadriceps muscle (rectus femoris and vastus intermedialis) thickness was 1.3 cm in LPA whereas 2.8 cm in VPA with (p≤0.001) soleus muscle thickness being 1 cm in LPA and 2.2 cm. Conclusions: Physical activity levels are found to be positively related to the peripheral muscle mass. VPA was associated with the greatest muscle thickness (p ≤ 0.001). These findings highlight the importance of habitual physical activity for maintaining peripheral muscle mass in young adults.