Training response and time course adaptations to sprint interval training and moderate intensity continuous training in sedentary young people

BACKGROUND: Endurance training has several health benefits, mainly mediated by the improving of cardiorespiratory fitness (CRF). It is known that sprint interval training (SIT) and moderate intensity continuous training (MICT) could improve similarly maximal oxygen uptake, a component of CRF. Nevertheless, little is known if SIT could modify other markers of CRF like ventilatory threshold and efficiency in comparison to MICT. Additionally, the evolution of markers related to the adaptations of both kinds of training has been less explored. Thus, this study aimed to examine and compare the training response and time-course adaptations of both training methodologies. METHODS: Twenty sedentary volunteers were randomly allocated to 12 sessions of MICT or 12 sessions of low volume SIT. Maximal oxygen uptake, peak power output (PPO), first ventilatory threshold (VT1), and efficiency were assessed pre-and post-training. A training analysis along sessions was done to establish how was the evolution of adaptations to training. RESULTS: In the pre-post comparison, the SIT group improved significantly maximal oxygen uptake, power at VT1, and PPO, whereas the moderate intensity continuous training group only significantly improved PPO at VT1. No differences were observed between groups in PPO and PPO at VT1, both at baseline and at follow-up. Training trend analysis shows a continuous improvement in both groups. CONCLUSIONS: Low volume sprint interval training is a time-effective strategy to improve CRF parameters such as V? O2max and VT1, in sedentary subjects compared to moderate intensity continuous training. Both training methodologies showed continuous and linear response after 12 sessions.