A 6-month personalized endurance exercise program improves tonic cardiovascular autonomic function but not psychological well-being.

Physical exercise (PE) is widely recognized for its benefits on physical and mental health. Yet its mechanisms of action on psychological outcomes remain insufficiently understood, especially regarding the role of tonic (under resting conditions) and challenge-induced response of the autonomic nervous system. This study examined the impact of a six-month personalized, endurance exercise program on autonomic cardiovascular and psychological indices in sedentary middle-aged adults. Forty-two participants (35-65 years old) were recruited to undergo laboratory assessments of heart rate variability (HRV), baroreflex sensitivity (BRS), heart rate (HR), and mean blood pressure (MBP) at rest and during a handgrip test (i.e., a response to a physical challenge), alongside validated questionnaires assessing depression, anxiety, resilience, somatization, and emotion regulation at baseline, and after three and six months of physical training. Results revealed significant improvements in autonomic cardiovascular function with a specific temporal pattern: HR decreased and BRS increased after three months and remained stable at six months, while HRV and MBP improved only after six months. These effects were all observed at the tonic level, with the training not affecting the cardiovascular response to the handgrip test. Unexpectedly, no stable effect was found on psychological variables after three or six months of personalized PE. In addition, changes in cardiovascular markers did not predict improvements in psychological outcomes. This study reinforces long-term PE programs as a scalable means to enhance cardiovascular and autonomic health, but yields limited evidence that such autonomic gains are associated with meaningful psychological improvements.