The effects of high-intensity interval training versus moderate-intensity continuous training on athletes' aerobic endurance performance parameters.

Objective: To systematically evaluate and meta-analyze the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on athletes of aerobic endurance performance parameters. Methods: PubMed, Web of Science, EBSCO, Embase, and Cochrane databases were searched. The assessment of quality was conducted employing The Cochrane Risk of Bias Assessment Tool, while heterogeneity examination and subgroup analysis were performed. Moreover, regression and sensitivity analyses were executed. Results: There was no significant difference between the effects of HIIT and MICT on the enhancement of athletes' running economy (RE) (P > 0.05); 1–3 weeks and 4–9 weeks of HIIT were more effective in improving athletes' maximum oxygen uptake (VO2max) (P < 0.05), and 10 weeks and above were not significant (P > 0.05); 1–3 weeks of HIIT was more effective in improving athletes' anaerobic threshold (AT) (P < 0.05), and 4–10 weeks was not significant (P > 0.05); 3 weeks of high-intensity interval training (HIIT) did not significantly enhance athletes' minute ventilation (VE) (P > 0.05), whereas a duration of 6–10 weeks yielded superior results (P < 0.05); 8 weeks of moderate-intensity continuous training (MICT) did not significantly enhance athletes' hemoglobin (Hb) level (P > 0.05), whereas a duration of 2–3 weeks yielded superior results (P < 0.05). Conclusions: (1) HIIT and MICT have similar effects on enhancing athletes' RE. (2) 6–9 weeks' HIIT was more effective in improving athletes' VO2max and VE, and 3 weeks' HIIT was more effective in improving athletes' AT. (3) Within 3 weeks, MICT was more effective in improving the Hb level of athletes. Registration number on PROSPERO: CRD42024499039. [ABSTRACT FROM AUTHOR]