Comparison of continuous moderate training with high intensity interval training on cardiopulmonary exercise test variables in patients with coronary artery disease: A meta-analysis

Background: Cardiovascular rehabilitation has the objective of reducing the risks of mortality and within this intervention there are two training modalities: high intensity interval training (HIIT) and moderate continuous intensity training (MIT). The exercise prescription is performed by cardiopulmonary exercise test. There are differences about which one is the best training for this patient. Aim: To compare the effects of HIIT and moderate continuous training on the variables of the cardiopulmonary exercise test (CPX) in patients with coronary artery disease. Methods: This is a systematic review of randomized clinical trials on coronary artery disease. This study was registered on PROSPERO. The search was executed on the databases: Medline, Scielo, Lilacs and Pedro. The selection of studies was a two-phase process: Reading of title and abstract and reading of full article. The data extraction was performed by the transcription of information. The methodological quality was evaluated by the PEDro scale and the risk of bias scale. The statistical analysis was performed using the RStudio software by random effect model and was applied the Q-Cochran test to evaluate the statistical heterogeneity. Results: 10 clinical trials were included. The methodological quality assessed by PEDro generated scores of four to nine, and the bias risk scale detected a low risk of bias. For the variables: VO2 peak (p = 0.04), Ventilatory Threshold (p = 0.05), HR max (p = 0.01), SBP max (p = 0.02), the HIIT proved to be more effective. The other variables did not present differences between the two modalities. Conclusion: HIIT showed to be the most effective training modality for the increase of VO2 max, Ventilatory Threshold, SBP max and HR max.Keywords: coronary heart disease, high intensity interval training, moderate continuous training.