Twelve weeks of low volume sprint interval training improves cardio-metabolic health outcomes in overweight females

ABSTRACT

This study compared the effects of 12-week sprint interval training (SIT), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT) on cardiorespiratory fitness (V̇O_2peak), body mass and insulin sensitivity in overweight females. Forty-two overweight women (age 21.2 ± 1.4 years, BMI 26.3 ± 2.5 kg·m⁻²) were randomized to the groups of SIT (80 × 6-s sprints + 9-s rest), and isoenergetic (300KJ) HIIT (~9 × 4-min cycling at 90% V̇O_2peak + 3-min rest) and MICT (cycling at 60% V̇O_2peak for ~ 61-min). Training intervention was performed 3 d·week⁻¹ for 12 weeks. After intervention, all three groups induced the same improvement in V̇O_2peak (~ +25%, p < 0.001) and a similar reduction in body mass (~ – 5%, p < 0.001). Insulin sensitivity and fasting insulin levels were improved significantly on post-training measures in SIT and HIIT by ~26% and ~39% (p < 0.01), respectively, but remain unchanged in MICT. In contrast, fasting glucose levels were only reduced with MICT (p < 0.01). The three training strategies are equally effective in improving V̇O_2peak and reducing body mass, however, the SIT is time-efficient. High-intensity training (i.e. SIT and HIIT) seems to be more beneficial than MICT in improving insulin sensitivity.

Abbreviations: BMI: body mass index; CVD: cardiovascular disease; HIEG: hyperinsulinaemic euglycaemic glucose; HIIT: high-intensity interval training; HOMA-IR: homeostasis model assessment of insulin resistance; HR: heart rate; MICT: moderate-intensity continuous training; RPE: ratings of perceived exertion; SIT: sprint interval training; T2D: type 2 diabetes; V̇O_2peak: peak oxygen consumption

KEYWORDS:

• Exercise
• interval training
• weight reduction
• cardio-metabolic health

Acknowledgments

The study was supported by a research grant from University of Macau (MYRG2014-00116-FED). The views expressed are those of the authors and not necessarily those of the UM.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Universidade de Macau [MYRG2014-00116-FED].