Active adults have thicker peripheral muscles and diaphragm: A cross-sectional study [version 2; peer review: 1 approved with reservations, 2 not approved]

Background: The association between exercise and muscle build-up is a long-run connection. Whereas limited physical activity doesn't do well with muscle build-up. 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: Patients ranging from 18-35 were chosen for this study. After enquiring about lifestyle factors like -smoking and drinking, out of 91 patients 30 patients smoke regularly and 6 patients had drinking habits. Also regarding occupation, 74.7% were employed and 25% were unemployed. We conducted this study on 91 participants who were grouped based on self-reported physical activity and sitting time levels based on IPAQ scores and underwent ultrasonography for quadriceps (rectus femoris and vastus intermedialis), soleus muscle, and diaphragm. 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=