The Effect of Two Types of Sprint Interval Training on Fat Oxidation during Recovery in Active Women

Sprint interval training (SIT) includes repeated bouts of maximal intensity less than 30 seconds, which can improve fat oxidation rate post exercise recovery. Therefore, this study compared the effect of two sprint interval training protocols on fat oxidation rate in recovery in active women. 10 active women (mean age, 23.8 ± 2.82 years, weight, 57.2 ± 6.97 kg) voluntarily participated in this study. Participants completed 2 SIT protocols in a cross-over design with a 6-day interval: the first protocol (24 × 5-sec. bouts, 40-sec. recovery) and the second protocol (4 × 30-sec. bouts, 240-sec. recovery). Protocols matched for the duration of work (2 min.) and recovery (16 min.), as well as the work/recovery ratio (1:8). Energy expenditure (EE) and fat oxidation rate in recovery were calculated by gas exchange collected during 90 minutes. Results showed that fat oxidation was significantly lower during recovery 5:40 (0.082 g/min.) than training 30:240 (0.098 g/min.) (P<0.05). But, EE during training (160.11 kcal) and EE during recovery (100.31 kcal) were significantly higher than EE during training 30:240 (127.48 kcal) and EE during recovery 30:240 (88.26 kcal) (P<0.05). The present results showed that despite the higher EE during training 5:40 compared with training 30:240, SIT with longer work/recovery ratio had a greater effect on using fat during recovery after training.