Commentary: Why sprint interval training is inappropriate for a largely sedentary population

Citation: Del Vecchio FB, Gentil P, Coswig VS and Fukuda DH (2015) Commentary: Why sprint interval training is inappropriate for a largely sedentary population. In this commentary, we explain why the recent manuscript by Hardcastle et al. (2014), which conveyed the opinion that sprint interval training (SIT) is inappropriate for sedentary individuals, may be misguided and propose an alternate view on this issue. Specifically, the main disagreements to consider involve reduced pleasure, self-esteem, adherence, and motivation with SIT, as well as the potential complexities involved with controlling exercise intensities. Minimal doses of exercise for health are somewhat limited within exercise recommendations (Garber et al., 2011) which tend to gravitate toward moderate intensity continuous exercise (MICE). However, it appears that 150 min/week of MICE is insufficient for weight loss/regain and to influence obesity-related risk factors (Church et al., 2009). Thus, interval-based training at varying intensities is advocated to address health and disease (Gibala et al., 2012). With ∼31% of the world's population being sedentary (Hallal et al., 2012), those who aim to improve previously mentioned health goals, SIT, which is a specific type of high-intensity intermittent training (HIIT; Buchheit and Laursen, 2013), may be an advantageous exercise strategy (Del Vecchio et al., 2013). To advocate for decreased pleasure with increasing intensity, Hardcastle et al. (2014) employ a review article that at no point mentions HIIT or SIT but primarily focused on continuous exercise at ∼85% of VO 2 reserve (Ekkekakis et al., 2011). In a direct comparison of single MICE or HIIT sessions, Oliveira et al. (2013) observed greater ratings of perceived exertion during HIIT, but no difference in physical activity enjoyment between the two types of exercise. In addition to the lack of reference to SIT or HIIT in the currently discussed Opinion Article (Hardcastle et al., 2014), the authors employ an " invited paper " (Parfitt and Hughes, 2009) which focuses on self-selected exercise intensity and self-regulation to support the notion that " enjoyment is also a predictor of exercise adherence and most people do not enjoy high intensity exercise. " Contrary to the suggestions, in a controlled trial, HIIT was shown to be more enjoyable than MICE (Bartlett et al., 2011). Similar results were found in varying populations (Crisp et al., 2012; Jung et al., 2015; Martinez et al., 2015), however, long-term evaluation is still needed.