A two-year examination of the relation between internal and external load and heart rate variability in Australian Rules Football

• Published in: Journal of sports sciences Vol. 42; no. 15; pp. 1400 - 1409
• Main Authors: O'Connor, Fergus K., Doering, Thomas M., Chapman, Neil D., Ritchie, Dean M., Bartlett, Jonathan D.
• Format: Journal Article
• Language: English
• Published: England Routledge 02-08-2024; Taylor & Francis Ltd
• Subjects: athlete wellbeing; Australian football; exercise; Heart rate; Physiological monitoring; Professional soccer; team sport; Training; training load; Work experience; exercise; athlete wellbeing; team sport; training load; Physiological monitoring
• ISSN: 0264-0414; 1466-447X; 1466-447X
• DOI: 10.1080/02640414.2024.2390238

The relationship between heart rate variability (HRV) and training load in team-sport is unknown. We therefore assessed relations between completed training-load in the previous 1-, 3- and 7-days and waking HRV in professional Australian Rules Football. Linear-mixed models analysed changes in HRV, considering training load from the previous 1-, 3- and 7-days. Total Distance (TD), distance >14.4 km - h−1 (HSR) and >24.9 km - h−1 (Sprint-Distance), duration >85% max heart rate and Rating of Perceived Exertion were included as independent variables. Sub-group analysis of season-phase and years of professional experience was also conducted. Increased three-day Sprint-Distance reduced HRV in the first 8-weeks of pre-season (−13.1 ms, p = 0.03) and across the data collection period (−3.75 ms, p = 0.01). In first-year players, higher previous-day (−63.3 ms, p=0.04) and seven-day TD (−38.2 ms, p = 0.02) reduced HRV, whilst higher seven-day HSR increased HRV (34.5 ms, p = 0.01). In players with five-to-seven years of professional experience, higher three-day (−14.4 ms, p = 0.02) and seven-day TD (−15.7 ms, p = 0.01) reduced HRV, while higher three-day HSR increased HRV (12.5 ms, p = 0.04). In players with greater than eight years of professional experience, higher previous-day Sprint-Distance reduced HRV (−13.1 ms, p < 0.008). Completed training load across the previous 7-days influences HRV, but the relation between variables is complex and influenced by professional experience and season-phase.