Ultrasound characteristics vs. outdoor activities impacts on obese adolescents: a cross-sectional cardiopulmonary study

Obesity among adolescents is rising, raising concerns about future cardiopulmonary disease. It’s unclear if this group has impaired cardiopulmonary function and whether this stems from muscle issues or sedentary behavior.

This cross-sectional study compared obese/overweight (n = 29) and non-obese (n = 29) adolescents (age ~ 21 yrs). It assessed cardiopulmonary function, axial rotation, muscle quality / quantity (respiratory, abdominal, gluteal), and outdoor activity.

Non-obese females had significantly more weekly outdoor activities. Cardiopulmonary results showed mixed findings: the obese group had higher maximum voluntary ventilation (MVV) and peak heart rate (HRpeak), while the non-obese group had better resting heart rate (HRrest) and oxygen consumption per kilogram (VO2/kg). The obese group had thicker sternocleidomastoid, rectus abdominis (RA), and gluteal muscles, but poorer muscle quality (ultrasound grayscale) in the upper trapezius and RA compared to the non-obese group. In obese females, higher VO2/kg correlated with better RA quality, while higher peak VO2 correlated with less outdoor activity time. Muscle imbalance was only seen in non-obese females and was positively associated with activity levels.

In comparison to non-obese peers, obese/overweight adolescents show inferior cardiopulmonary function and reduced muscle performance. While some muscles are thicker in the obese group, lower grayscale values indicate poor quality/function. Muscle assessment should not rely solely on thickness. Although outdoor activity shows a positive correlation with some cardiopulmonary parameters, muscle metabolic issues related to sedentary behavior likely represent a significant correlate of cardiopulmonary dysfunction.