Evaluating the efficacy of a high intensity interval training program (Sport-HIIT) on health and well-being among adolescents’ participating in organised-sport.

This program will investigate the effects of the provision of ‘Sport-HIIT’ in the first 10 minutes of training of various sports. Consenting coaches (will be provided with resources/instructions) and their players will participate in a weekly HIIT session (10 minutes in total i.e., a 2 minute dynamic warm up and a 1 x 8 minute HIIT session), for 8 weeks, i.e., delivered their usual coach. A research member can instruct/demonstrate how to conduct a session with the coaches i.e., provide training to assist them in their delivery. (Notably, coaches will be provided any additional training necessary to conduct their own Sport-HIIT sessions for the remaining weeks of the program before normal training.) The type of HIIT sessions players participate in may vary but will consist of a combination of aerobic and resistance exercises in a 30 sec : 30 sec rest to work ratio. Resources i.e., HIIT cards and music will be supplied and provided by a research member. All players can participate in the HIIT training sessions but only those players returning signed parental consent forms will complete assessments. Participants will be given a brief survey measuring their HIIT self-efficacy, future intentions for physical activity, affective state and enjoyment relating to the sessions. They will also participate in a series of fitness tests including the 20m SRT (beep test) measuring cardio respiratory fitness, the push-up test measuring muscular fitness (upper body) and the standing long jump test to assess muscular power (lower body). Measurements and surveys will be collected at baseline and post-test (approx. 8 weeks) by a member of the research team. Sport-HIIT will be run during the playing seasons throughout 2021, and offered to the majority of organised sporting clubs in the Hunter Region, NSW, Australia. Sport-HIIT will be implemented and evaluated as a randomised controlled trial (RCT). All staff/players who choose to participate in the study will be randomised, by a computer generated algorithm, into either the intervention group (who complete the program straight away) or the wait-list control group (who will receive the program, just delayed). Each sport will involve 4 teams of which 2 will be randomised to intervention and 2 assigned to a wait-list control The study will be completed in two (2) phases: Phase 1: GPS tracking during game play & Phase 2: SPORT-HIIT Study Phase 1: Participants will wear a GPS during game play. The use of the GPS devices will be explained to all players before the first game (i.e., what they are and what they do), and players will also have an opportunity to ask any questions before their use. The GPS devices will be distributed by a member of the research team accompanied by the coach. The GPS is a small device placed in the pocket of a chest vest that can be worn over players t-shirt. The GPS device can be fitted by the player themselves on the playing grounds/ovals. At the end of the game, either the coach and/or research member will collect the GPS devices. The GPS will not be labelled with players details and have no visual representation of the data it collects. a) The Sport HIIT study will involve players completing assessments (psychological and physical) before and after the 8-week Sport HIIT program during their normal training sessions and at their normal training location (or immediately before training if more suitable for the coach and players). Coaches will supervise whilst a research member implements the measures with the exception of the GPS devices, which coaches may simply hand out to their players. b) Following baseline assessments, coaches will implement tailored 8-min Sport-HIIT sessions (following a 2 min dynamic warm up) at the start of each normal training session (for 8-weeks). All Sport-HIIT sessions with include a range of body weight and aerobic exercises and are designed to be enjoyable i.e., encouraging participants to work in pairs of their choice (with one participant undertaking the ‘work’ phase while their partner rests). As the intervention progresses, participants will also be provided with additional elements of choice including: music (playlists) and exercise choices during a workout for example. Importantly, graded exercises to suit all fitness/skill levels will be provided. The intensity of exercises completed in the sessions will be assessed via HR monitors. The HR monitors will be worn on a chest strap, connected wirelessly to a receiver. The HR monitor will be worn during physical sessions i.e., during the Sport-HIIT sessions. A member of the research team accompanied by the coach will distribute HR monitors. Students will be instructed on how to put on the HR monitors themselves. HR monitors will be collected and cleaned at the end of each Sport-HIIT session. Depending on each of the participant(s) i.e., experience, fitness levels, any previous injuries etc. sessions will aim for an intensity of 70 to 90 percent max heart rate during the sessions, as measured by the HR monitors. Notably, this is dependent on the capability of each participant though representative of the overall aim to achieve ‘High Intensity’ as described by a plethora of research. HIIT cards are being designed specifically for this study i.e., to ensure they are appealing/fun/engaging for the youth. All Sport-HIIT sessions with include a range of body weight and aerobic exercises with images on how to perform each skill correctly on the cards. Specific examples of exercises completed in the HIIT sessions, may include e.g. skipping, push-ups, lunges, squats, shuttle runs etc. To monitor adherence to the intervention a roll will be recorded by the coach each session. Players aged 12-18 years will be invited and are eligible to participate in the study. Face to face delivery will be conducted by their normal coach (with varying levels experience, appropriate for community sport).