Different exercise training modalities similarly improve heart rate variability in sedentary middle‑aged adults: the FIT‑AGEING randomized controlled trial Navarro Lomas, Ginés Dote Montero, Manuel Alcántara Alcántara, Juan Manuel Plaza Florido, Abel Adrián Castillo Garzón, Manuel Amaro Gahete, Francisco José Autonomic nervous system Vagal activity, physical activity Training Cardiometabolic health Funding for open access charge: Universidad de Granada/CBUA. Purpose This study aimed to investigate the influence of different exercise training modalities on heart rate variability (HRV) in sedentary middle-aged adults; and to study whether changes in health-related outcomes (i.e., body composition and cardiometabolic risk) are associated with those hypothetical HRV changes in sedentary middle-aged adults. Methods A total of 66 middle-aged adults (53.6 ± 4.4 years old; 50% women) were enrolled in the FIT-AGEING study. We conducted a 12-week randomized controlled trial. The participants were randomly assigned to 4 groups: (a) a control group (no exercise); (b) a physical activity recommendation from the World Health Organization group (PAR); (c) a high-intensity interval training group (HIIT); and (d) a high-intensity interval training group adding whole-body electromyostimulation (HIIT + EMS). Results All exercise training modalities induced changes in HRV parameters (all P ≤ 0.001) without statistical differences between them (all P > 0.05). We found associations between changes in body composition and cardiometabolic risk and exercise-related changes in HRV. Conclusion Our results suggest that different exercise interventions (i.e., PAR, HIIT and HIIT + EMS) induced an enhancement of HRV in sedentary middle-aged adults. Our findings support the notion that exercise-related changes in HRV are associated with changes in body composition and cardiometabolic risk after the intervention program 2022-05-25T10:49:39Z 2022-05-25T10:49:39Z 2022-05-10 info:eu-repo/semantics/article Navarro-Lomas, G... [et al.]. Different exercise training modalities similarly improve heart rate variability in sedentary middle-aged adults: the FIT-AGEING randomized controlled trial. Eur J Appl Physiol (2022). [https://doi.org/10.1007/s00421-022-04957-9] http://hdl.handle.net/10481/74988 10.1007/s00421-022-04957-9 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Springer