Effect of High-Intensity Interval Training on Total, Abdominal and Visceral Fat Mass: A Meta-Analysis.
Level 1 - systematic review of randomized trials
Meta-analysis of intervention trials
PubMed 29127602 · doi:10.1007/s40279-017-0807-y
What was done
A systematic review and meta-analysis of electronic databases evaluating the efficacy of high-intensity interval training (HIIT) on fat mass in normal-weight and overweight/obese adults. Stratified analyses were conducted by exercise modality (running vs. cycling), target intensity, sex, body weight status, and body composition measurement method. The meta-analysis included 39 studies comprising 617 participants (mean age 38.8 ± 14.4 years, 52% female).
What was found
HIIT significantly reduced total fat mass (p = 0.003), abdominal fat mass (p = 0.007), and visceral fat mass (p = 0.018), with no differences between sexes. Running was more effective than cycling for reducing total and visceral fat mass. Target intensities above 90% peak heart rate were more effective for whole-body adiposity, whereas lower intensities had greater effects on abdominal and visceral fat mass. Significant abdominal and visceral fat reductions were only detected when measured by CT or MRI. Specific effect sizes, confidence intervals, and baseline-to-post absolute differences were not reported in the abstract.
Why it matters
This meta-analysis demonstrates that HIIT reduces visceral and abdominal fat stores across sexes, with running conferring advantages over cycling and intensity modulating depot-specific fat loss.
Limits
The abstract reports p-values but omits effect sizes and confidence intervals. The included literature is composed of very small trials (averaging ~16 subjects per study), and wide variation in HIIT protocols and incomplete reporting of cycling interventions limit precision.
Cited by
- supports Aerobic exercise and high-intensity interval training (HIIT) effectively reduce visceral fat.