The effect of recovery interval duration on maximal aerobic capacity following 6 weeks of sprint interval training (SIT) in a group of inactive individuals

High intensity interval training is a time efficient alternative to more traditional modes of cardiovascular training. The following study investigates the effect of recovery interval duration on maximal aerobic capacity following 6-weeks of sprint interval training (SIT) in a group of inactive individuals. The study recruited 14 (female, n = 8) healthy sedentary individuals (i.e. mL·kg·min-1. The participants were randomly allocated into two groups; Group 1 (three 10-minute sessions per week) (male, n = 3; female, n = 3; 23 ± 4 years; 1.7 ± 0.1 m; 74 ± 7 kg) or group 2 (Six 5-minute sessions per week) (male, n = 3; female, n = 5; 22.9 ± 5.2 years; 1.7 ± 0.1m; 70 ± 12 kg). Both groups completed the same period of - 3 = 15 seconds and 20 seconds for the remaining 3 weeks). Group 1 repeated the protocol immediately, whereas group 2 underwent a minimum of 4 hours rest before completing the protocol again. Training was completed three days a week. Maximal aerobic capacity ( O2peak) was determined before and 3-days after the exercise program via a cycling ramp test to exhaustion. Prior to the intervention, maximal aerobic capacity and power was 36 ± 5 mL·kg·min-1 and 213 ± 19 W for group 1, and 38 ± 8 mL·kg·min-1 and 216 ± 58 W for group 2. Rating of perceived exertion (RPE) and affect (feeling scale) was also measured on selected training sessions. All measures were analysed with a paired samples t-test using Graph Pad Prism 8 with significance accepted at P < 0.05. Both groups presented significant changes in O2peak (Group 1 39 ± 6 mL·kg·min-1; 10 ± 8%; P = 0.0253) (Group 2 41 ± 7 mL·kg·min-1; 9 ± 8%; P = 0.0095). However, there was no difference reported between conditions (P = 0.9483). In conclusion, three 10-minute sessions per week of sprint interval cycling improve maximal aerobic capacity to the same extent as six 5-minute sessions per week