Key result
High-intensity interval exercise and moderate-intensity continuous exercise induced similar transient alterations in heart rate variability and elevations in cardiac troponin T, with no significant differences between modalities.
Why the study?
It was uncertain whether exercise modality (high-intensity interval vs moderate-intensity continuous) mediates exercise-induced changes in markers of pro-arrhythmogenic state or cardiac damage.
Does high-intensity interval exercise alter heart rate variability and cardiac troponin T differently than moderate-intensity continuous exercise in sedentary, overweight/obese females?
RCT (n=14)
Open-label
Randomized (by lottery) crossover design
No
Does high-intensity interval exercise alter heart rate variability and cardiac troponin T differently than moderate-intensity continuous exercise in sedentary, overweight/obese females?
p-value: p=>0.05
Workload-matched high-intensity interval and moderate-intensity continuous exercise induce similar transient alterations in autonomic activity and elevations in cardiac troponin T, suggesting HIE does not pose a higher acute cardiac risk than MCE in sedentary obese females.
HIE and MCE produce similar transient HRV and cTnT changes; extends evidence that HIE poses no excess acute cardiac risk in sedentary obese females.
BACKGROUND: It remains uncertain whether exercise modality (high-intensity interval [HIE]; moderate-intensity continuous [MCE]) mediates exercise-induced changes in markers of pro-arrhythmogenic state and/or cardiac damage. This study examines heart rate variability (HRV) and cardiac troponin T (cTnT) kinetic responses to HIE and MCE. METHODS: Fourteen sedentary, overweight/obese females completed two trials including HIE (2-min running at 90% V̇O<inf>2max</inf> followed by 2-min running at 50% V̇O<inf>2max</inf>, repeated for 60 min) and MCE (70% V̇O<inf>2max</inf> steady-state running for 60 min) in a randomized, counterbalanced fashion. Supine HRV was evaluated as root mean square of successive differences (RMSSD), normalized low-frequency (LF) and high-frequency (HF) spectral power, as well as the LF/HF ratio before (PRE), immediately (0 HR), 3 (3 HR) and 24 (24 HR) hours after exercise. Serum cTnT was assessed using a high-sensitivity assay at the same time-points and the values were corrected for plasma volume changes. RESULTS: Exercise temporarily altered all HRV indices (i.e. RMSSD and HF decreased; LF and LF/HF ratio increased at 0 HR, all P<0.05) but a rebound increase of RMSSD was observed at 24 HR, and the kinetic responses of HRV were similar between exercise modalities. The cTnT was significantly elevated (P<0.05) after exercise at 3 HR (by 688%) and 24 HR (by 374%) with no between-modality differences. There was no significant correlation between delta change in cTnT and HRV metrics. CONCLUSIONS: Exercise modality (workload-equivalent HIE vs. MCE) did not mediate exercise-induced alteration in autonomic activity and cTnT elevation, and it seems these are largely separate exercise-induced phenomena.
No takes yet. Share an insight, caveat, or question.
Huang et al. (2021) conducted an RCT in Sedentary, overweight/obese (n=14). High-intensity interval exercise (HIE) vs. Moderate-intensity continuous exercise (MCE) (70% VO2max steady-state running for 60 min) was evaluated on Between-modality differences in heart rate variability (HRV) indices and cardiac troponin T (cTnT) elevation up to 24 hours post-exercise (p=>0.05). High-intensity interval exercise and moderate-intensity continuous exercise induced similar transient alterations in heart rate variability and elevations in cardiac troponin T, with no significant differences between modalities.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: