Energy matching of a high‑intensity exercise protocol with a low‑intensity exercise protocol in young people

Recent research suggests that exercise is a beneficial adjunct therapy for many health conditions [1]. For clinicians to be able to prescribe exercise to patients, more information is required around the intensity and duration of exercise and more specifically, guidelines need to be developed to ensure a consistent approach to patient care. When design-ing exercise intervention trials to explore the effects of dif-ferent intensities, the same volume of exercise needs to be employed between experimental groups to ensure that any differences in responses result from differences in intensity and not energy expenditure (EE). This is because metabolic and peripheral adaptations such as mitochondrial and capil-lary density respond to the volume of exercise training rather than the intensity [2].The current study was undertaken as pilot work for a ran-domised controlled trial of energetic activity for depression in young people (13–17 years) (the READY trial: https:// www. journ alsli brary. nihr. ac. uk/ progr ammes/ hta/ 177810/#/). Prior to undertaking the READY trial, the protocol for the exercise intervention was pilot tested. To ensure fair comparison between the high- and low-intensity group exer-cise protocols they needed to be energy matched. The high-intensity exercise protocol was adapted from Taylor etal. [3] which included activities such as boxing and football drills. These had been previously demonstrated to be acceptable, enjoyable and engaging amongst young people (14.0 ± 0.3 years). The duration of the high-intensity exercise interven-tion previously utilised by Taylor etal. [3] was 9 min, which was achievable by the participants and, therefore, the present pilot tested used this duration for one of the activities: box-ing. The low-intensity exercise intervention selected for the study was indoor walking football. At the time of writing this, there was no research measuring exercise intensity or EE in indoor walking football in young people. However, as walking at comfortable speeds is categorised as low intensity [4], the research team chose it as an appropriate activity. Walking per se would have brought an extraneous variable as it would have had to be completed outside and hence may affect depressive symptoms differently to indoor exercise. Nevertheless, for the purpose of this pilot testing, simulated walking football was compared with walking to ensure there were no substantial differences in intensity.