Investigating the Role of Exercise Pattern in Acute Cardiovagal Recovery

• Published in: Medicine and science in sports and exercise
• Main Authors: Sasso, John P, Ivanchikov, Sofia, Coates, Kyla, Stewart, Liam, Wright, Stephen P, Seiler, Stephen, Shave, Robert, Eves, Neil D
• Format: Journal Article
• Language: English
• Published: United States 17.10.2024
• ISSN: 1530-0315
• DOI: 10.1249/MSS.0000000000003580

Research on intermittent training has mainly focused on the effects of exercise intensity while overlooking the specific impact of the modulations associated with alternating exercise and recovery. This study investigated how the frequency of modulations during moderate-intensity exercise affects post-exercise vagal reactivation. Healthy, active females and males aged 18-39 years were recruited for the study. Participants completed three treadmill running sessions on separate days. Each moderate-intensity session accumulated 30 min at 90% of the intensity associated with the second ventilatory threshold and were performed as either high-frequency intermittent (HiFi; 15 x [2 min + 2 min recovery]), low-frequency intermittent (LoFi; 5 x [6 min + 2 min recovery]), or continuous training (MICT; 1 x 30 min). Heart rate recovery (HRrec) at 1 min and heart rate variability recovery (HRVrec; lnRMSSD) were assessed in response to submaximal constant-speed tests performed prior to (CST1) and following (CST2) each of the exercise sessions. HRrec, HRVrec, blood lactate (BLa), and blood pressure were also collected during the exercise sessions. Twenty-one individuals (8 females, 13 males) participated in the study. HRrec from CST2 was faster in HiFi vs. MICT (p < 0.001), while HRVrec post-CST2 was higher following HiFi vs. both LoFi (p = 0.024) and MICT (p < 0.001). BLa increased in all conditions (p = 0.007) but remained lower during HiFi compared to LoFi and MICT (both p < 0.001). Diastolic blood pressure did not change during exercise with HiFi (p = 0.939) but decreased during LoFi (p = 0.006) and MICT (p = 0.008). Exercise pattern influences the physiologic response to exercise. Higher frequencies of modulations can preserve vagal activity and expedite post-exercise recovery, suggesting moderate-intensity intermittent exercise as a potential strategy to mitigate autonomic impact and acute physiological stress while maintaining total work performed.