Short-Term (<8 wk) High-Intensity Interval Training in Diseased Cohorts.

Abstract

Background and aim Exercise training regimes can lead to improvements in measures of cardiorespiratory fitness (CRF), improved general health, and reduced morbidity and overall mortality risk. High-intensity interval training (HIIT) offers a time-efficient approach to improve CRF in healthy individuals, but the relative benefits of HIIT compared with traditional training methods are unknown in across different disease cohorts.

Methods This systematic review and meta-analysis compares CRF gains in randomized controlled trials of short-term (

Results Thirty-nine studies met the inclusion criteria. HIIT resulted in a clinically significant increase in V˙O2peak compared with CON (mean difference [MD] = 3.32 mL·kg·min, 95% confidence interval [CI] = 2.56-2.08). Overall HIIT provided added benefit to V˙O2peak over MCT (MD = 0.79 mL·kg·min, 95% CI = 0.20-1.39). The benefit of HIIT was most marked in patients with cardiovascular disease when compared with MCT (V˙O2peak: MD = 1.66 mL·kg·min, 95% CI = 0.60-2.73; anaerobic threshold: MD = 1.61 mL·kg·min, 95% CI = 0.33-2.90).

Conclusions HIIT elicits improvements in objective measures of CRF within 8 wk in diseased cohorts compared with no intervention. When compared with MCT, HIIT imparts statistically significant additional improvements in measures of CRF, with clinically important additional improvements in V˙O2peak in cardiovascular patients. Comparative efficacy of HIIT versus MCT combined with an often reduced time commitment may warrant HIIT's promotion as a viable clinical exercise intervention.