Effects of run sprint interval training on healthy, inactive, overweight/obese women: A pilot study

Abstract

This study examined the effects of a 12 week, treadmill-based, run sprint interval training (SIT) protocol compared with that of a moderate-intensity continuous training (MICT) protocol in healthy, inactive, overweight/obese women, on cardiovascular disease risk factors. After random assignment, the SIT group completed 4–10 × 30 s maximal sprints, with a 4 min active recovery between sprints, and the MICT group completed 30–60 min at moderate intensity (45–55% heart rate reserve (HRR)). The rate of perceived exertion (RPE) was recorded for each session, and perceived enjoyment was quantified every 3 weeks. Clinical and fitness testing were completed at baseline, 6 weeks, and 12 weeks. Twelve female participants (age: 34.1 ± 6.1; body mass index (BMI): 31.3 ± 6.8; VO 2peak : 27.0 ± 6.2) completed the intervention. There were significant main effects for time for VO 2peak ( p = 0.001), body fat percentage ( p = 0.001), and session RPE ( p = 0.006). VO 2peak improved 20.7% in the SIT group ( n = 5) and 24.4% in the MICT group ( n = 7). Body fat percentage reduced by 1.7% in the SIT group and 2.6% in the MICT group. Perceived enjoyment was similarly high between the groups despite higher session RPE in the SIT group ( p = 0.441). SIT training on a motor-driven treadmill elicits similar improvements in oxygen utilization and body composition as moderate-intensity training in this population.