Effects of high-intensity interval training on cardiometabolic health: a systematic review and meta-analysis of intervention studies

Abstract

The current review clarifies the cardiometabolic health effects of high-intensity interval training (HIIT) in adults. A systematic search (PubMed) examining HIIT and cardiometabolic health markers was completed on 15 October 2015. Sixty-five intervention studies were included for review and the methodological quality of included studies was assessed using the Downs and Black score. Studies were classified by intervention duration and body mass index classification. Outcomes with at least 5 effect sizes were synthesised using a random-effects meta-analysis of the standardised mean difference (SMD) in cardiometabolic health markers (baseline to postintervention) using Review Manager 5.3. Short-term (ST) HIIT (<12 weeks) significantly improved maximal oxygen uptake (VO 2 max; SMD 0.74, 95% CI 0.36 to 1.12; p<0.001), diastolic blood pressure (DBP; SMD −0.52, 95% CI −0.89 to −0.16; p<0.01) and fasting glucose (SMD −0.35, 95% CI −0.62 to −0.09; p<0.01) in overweight/obese populations. Long-term (LT) HIIT (≥12 weeks) significantly improved waist circumference (SMD −0.20, 95% CI −0.38 to −0.01; p<0.05), % body fat (SMD −0.40, 95% CI −0.74 to −0.06; p<0.05), VO 2 max (SMD 1.20, 95% CI 0.57 to 1.83; p<0.001), resting heart rate (SMD −0.33, 95% CI −0.56 to −0.09; p<0.01), systolic blood pressure (SMD −0.35, 95% CI −0.60 to −0.09; p<0.01) and DBP (SMD −0.38, 95% CI −0.65 to −0.10; p<0.01) in overweight/obese populations. HIIT demonstrated no effect on insulin, lipid profile, C reactive protein or interleukin 6 in overweight/obese populations. In normal weight populations, ST-HIIT and LT-HIIT significantly improved VO 2 max, but no other significant effects were observed. Current evidence suggests that ST-HIIT and LT-HIIT can increase VO 2 max and improve some cardiometabolic risk factors in overweight/obese populations.

Similar cardiometabolic effects of high- and moderate-intensity training among apparently healthy inactive adults: a randomized clinical trial

“…Similarly, Earnest et al [54] observed similar improvements in the MetS Z -score and the number of MetS risk factors between overweight males who participated in HIT and MCT. Due to methodological differences across studies (i.e., sex; age; initial health, weight and fitness status; prescribed medication; type and intensity of exercise, or interval duration; length of the exercise program) and the impact of such differences on outcomes [55–57], it is difficult to draw general conclusions. These and other possible factors need to be studied.…”

The effects of sleep extension on cardiometabolic risk factors: A systematic review

“…However, the correlations between change in sleep duration and change in insulin sensitivity‐related outcomes indicate some role for increasing sleep duration. While this study certainly had limitations (no control group, no direct assessment of insulin sensitivity in response to a glucose challenge (Leproult et al., ), the extent to which fasting glucose levels were reduced was similar to that observed in individuals who were overweight or obese and undertook 12 weeks of high‐intensity interval training (Batacan, Duncan, Dalbo, Tucker, & Fenning, ). Although comparisons between the two interventions are difficult because of the differences in populations studied and reporting of the data, one might speculate that a sleep extension intervention may be as effective in improving fasting glucose and insulin levels as exercise, specifically high‐intensity interval training.…”

Efeito do treinamento intervalado de alta intensidade versus treinamento contínuo na composição corporal: uma revisão sistemática com meta-análise

“…Contudo, a interpretação dessa diferença deve ser cautelosa, pois a magnitude das alterações se encontram na margem de erro para medições de circunferên-cia de cintura 41 . Os achados desta meta-análise divergem com os resultados encontrados pelos de Batacan et al 42 . Nesse estudo foram avaliados 65 ensaios clínicos randomizados e não randomizados, onde foi encontrado melhora significativa para o HIIT na circunferência de cintura e percentual de gordura corporal, quando realizados ≥12 semanas, na população obesa e/ou com sobrepeso.…”