This cross-sectional study aimed to identify associations between clinical inflammatory risk markers, body composition, heart rate variability (HRV), and self-reported and objectively assessed physical activity (PA) in university students with overweight and obesity. Seventeen participants (eight females) completed a screening visit following a randomized controlled four-arm crossover trial period with 8 h of uninterrupted prolonged sitting, alternate sitting and standing, continuous standing, and continuous slow walking, respectively. Clinical inflammatory risk markers were obtained from venous blood samples, and PA was assessed using the International Physical Activity Questionnaire (IPAQ-SF) and ActiGraph wGT3X-BT accelerometers. HRV was recorded over 24 h using the Faros 180 Holter electrocardiogram (ECG). White blood cell (WBC) counts were significantly correlated with fat mass (FM; p = 0.03) and visceral adipose tissue (VAT; p = 0.04) and inversely correlated with moderate PA (p = 0.02). Light-intensity PA (LIPA) and moderate-to-vigorous PA (MVPA) were correlated with HRV parameters (p = 0.02), and LIPA was inversely correlated with interleukin-6 (p = 0.003) and c-reactive protein (p = 0.04) during different trial conditions. In university students with overweight and obesity, higher values of FM were negatively correlated with WBC count, and integrating LIPA and MVPA in the students' daily life strengthened their sympathetic-parasympathetic regulation and positively mediated anti-inflammatory mechanisms.
Keywords: biomarkers; health risk behavior; low-grade inflammation; obesity; objectively assessed physical activity; sedentary time; sympathetic–parasympathetic regulation; young adults.