Effectiveness of HIIE versus MICT in Improving Cardiometabolic Risk Factors in Health and Disease: A Meta-analysis.
Level 1 - systematic review of randomized trials
Meta-analysis of comparative trials
PubMed 32890201 · doi:10.1249/MSS.0000000000002506
What was done
A random-effects meta-analysis and meta-regression of 55 studies compared the effects of high-intensity interval exercise (HIIE, including HIIT and sprint interval training) versus moderate-intensity continuous training (MICT). Outcomes analyzed included maximal oxygen uptake (VO2max), flow-mediated dilation (FMD), body composition (BMI, body mass, percent body fat), blood pressure, lipid profiles (HDL, LDL, triglycerides, total cholesterol), inflammatory markers (CRP), and glucose metabolism indices (fasting glucose, fasting insulin, HbA1c, HOMA-IR). Subgroups evaluated included population type, age, duration, sex ratio, exercise modality, baseline values, and HIIE type.
What was found
HIIE was significantly superior to MICT in improving VO2max (d = 0.40, P < 0.001) and FMD (d = 0.54, P < 0.05). Conversely, MICT was superior to HIIE in improving HbA1c (d = -0.27, P < 0.05). No significant differences were observed between training modalities for BMI (d = -0.02), body mass (d = -0.05), percent body fat (d = 0.04), systolic blood pressure (d = -0.04), diastolic blood pressure (d = 0.03), HDL (d = -0.05), LDL (d = 0.08), triglycerides (d = 0.03), total cholesterol (d = 0.14), CRP (d = -0.11), fasting insulin (d = 0.02), fasting glucose (d = 0.02), or HOMA-IR (d = -0.04).
Why it matters
Neither modality is universally superior: HIIE confers greater benefits for cardiorespiratory fitness and vascular endothelial function, while MICT achieves better long-term glycemic control.
Limits
The abstract does not report the total number of human participants or assess risk of bias among included trials. Subgroup analyses showed significant heterogeneity across study populations, protocols, and baseline health states, and most cardiometabolic markers showed no difference between exercise types.
Cited by
- contradicts When exercise volume is equated, high-intensity interval training yields greater improvements in glucose regulation than continuous low- to moderate-intensity training.