Acute Effects of HIIT and MICT on Catestatin Dynamics in Young Males

Overview

Physical exercise acts as a major physiological stressor that alters cardiovascular and autonomic homeostasis. Catestatin (CTS), a bioactive peptide derived from chromogranin A (CgA), acts as a potent inhibitor of catecholamine secretion and modulates autonomic cardiovascular tone. However, the acute effects of distinct exercise modalities on circulating CTS dynamics and their associations with post-exercise autonomic recovery remain unclarified. The purpose of this study is to investigate the acute responses of serum catestatin and chromogranin A to high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in healthy sedentary young males, and to evaluate their potential relationship with post-exercise heart rate recovery (HRR). Participants completed an initial incremental performance test followed by either a single HIIT session or a MICT session on a cycle ergometer. Serial blood samples and continuous cardiovascular measurements were obtained before, immediately after, and throughout a 60-minute post-exercise recovery period.

Twenty healthy sedentary young adult males (aged 18-25 years) were assigned to either a high-intensity interval training group (HIIT, n=10) or a moderate-intensity continuous training group (MICT, n=10). Following an initial incremental maximal exercise test to determine individual exercise capacities, participants performed their assigned acute exercise protocol on a cycle ergometer separated by at least 48 hours. The MICT session consisted of 30 minutes of continuous cycling at 60-70% of maximum heart rate (HRmax), whereas the HIIT protocol comprised four 4-minute intervals at 85-95% HRmax interleaved with 3-minute active recovery periods. Serial venous blood samples were collected at baseline (Pre), immediately post-exercise (0 min), and at 15, 30, 45, and 60 minutes post-exercise to analyze serum catestatin and chromogranin A concentrations via enzyme-linked immunosorbent assay (ELISA). Continuous heart rate and intermittent blood pressure were monitored throughout the exercise bouts and during the 60-minute recovery phase. Post-exercise autonomic regulation was assessed using 1-minute (HRR1) and 5-minute (HRR5) heart rate recovery indices.