A Comparison of Goal-Oriented Guided Mental Imagery versus Goal Setting Interventions on Physical Activity Levels in Young, Inactive Adults with Overweight or Obesity Living in Australia

Goal -oriented guided imagery Materials: Participants in the goal-oriented guided mental imagery condition will be provided with imagery script recordings (audio) and an information sheet to explain how to perform guided mental imagery. The current study will utilise a modified version of Giacobbi and colleagues’ (2018) guided imagery script. The current study has two imagery scripts: a cardiorespiratory exercise script (practised at least four times a week) and a resistance training script (practised at least twice a week) The recording of the first imagery script (3 minutes 25 seconds) focuses on performing cardiorespiratory exercise and the recording of the second script (3 minutes 38 seconds) requests participants to create vivid and realistic images relating to resistance training. Participants will also be given a general exercise imagery script to allow for modification of the specific cardiorespiratory activities they could imagine while maintaining the following five specific scenarios: (1) imagining a place to exercise; (2) a slow-paced warm-up exercise of the participants’ choice; (3) images of a progressively more intense exercise; (4) imagining oneself coping with a vigorous activity; and (5) images encouraging participants to monitor exercise technique. Participants will be asked to perform guided mental imagery in a quiet environment prior to commencing the exercise. Participants will be asked to record if they had performed guided imagery each day in the online logbook provided by the researcher. All participants will receive by mail a set of two resistance bands, comprising two resistance levels (light and medium) to be used for the resistance exercise sessions during the 6-week exercise program. Participants will also be asked to complete an online logbook, specifically designed for participants to log their cardiorespiratory exercise session length (time) and their ratings of perceived exertion, which will be used to calculate their metabolic equivalent of task (MET). All participants will receive an information sheet specifically designed on types of cardiorespiratory exercise routines they might follow. This will ensure that participants have the autonomy to incorporate their preferred modes of cardiorespiratory exercise over the 6-week intervention. Procedure: Baseline testing Participants who are safe to proceed (or have subsequently provided medical approval to proceed) will attend a second, one-to-one virtual meeting (one hour duration) for baseline testing. During the baseline testing session, they will be tested on their muscular endurance. Muscular endurance will be assessed both pre- (baseline) and post-training (after the 6-week exercise program). The muscular endurance tests will comprise four types of exercise: (1) isometric, squat hold, (2) prone bridge hold, (3) push-ups to failure, and (4) curl-ups to failure. Participants will be allocated to either one of the two interventions Moderate intensity cardiorespiratory exercise should be performed at least four days a week, at any time of the day, for at least 30 minutes per session. Participants can engage in their own choice of cardio such as cycling, jogging, walking, or running. Participants will receive reminders to complete their cardiorespiratory exercise via Outlook. The reminders will include the type of exercise participants had opted for initially and their goals (either audio or written) to be reviewed prior to performing their exercise individually. The moderate-intensity cardiorespiratory exercise intensity will be measured using the metabolic equivalent of task minutes and Borg RPE The resistance training program will include two training sessions per week (12 sessions in total over six weeks) lasting 30 minutes each. These sessions will be split into two, three-week blocks over six weeks delivered by the researcher. The resistance exercise sessions( Ee.g., Neutral Grip Band Biceps curls, Diagonal Band pull apart) will progressively become more difficult as the participants adapt to the initial training stimuli. Who will deliver the program? The student investigator will deliver the program. The student investigator is accredited with level one strength and conditioning. Mode of delivery: The 6-week exercise program is delivered over the internet. The program is supported by telehealth. For both the initial and baseline testing, participants will have their virtual meeting the student investigator individually via Microsoft Teams. The resistance training will be conducted in groups of 5-6. Number of times the intervention will be provided (Duration, intensity, dose of intervention): Participants allocated to goal oriented guided imagery would be given a cardiorespiratory exercise script (practiced at least four times a week) and resistance training script (practiced at least twice a week), amounting to participants using guided imagery six times per week in total, equivalent to the goal setting condition. Participants will be asked to complete the guided imagery sessions 5 minutes prior to each exercise session. Participants will not be asked to aim for a target RPE for these exercises. Participants allocated to goal setting condition will be asked to read their goals at least 6 days out of 7 days in a week. Participants both allocated to goal oriented guided imagery or goal setting condition will be exposed to cardiorespiratory exercise, which would be performed at least four days a week, at any time of the day, for at least 30 minutes per session. The resistance training would be twice a week (12 sessions in total over six weeks) lasting 30 minutes each. Participants will be asked to complete the guided imagery sessions just before the resistance training session. Location The cardiorespiratory exercise would be performed by the participants their own at their place of choice. The resistance exercise sessions will be conducted over a group videoconference call by the researcher (Microsoft Teams) at a pre-scheduled time; hence all these workouts will be performed online, at participants’ place of choice. The intervention is personalised: Participants allocated to goal-oriented guided imagery will be given a general exercise imagery script to allow for modification of the specific cardiorespiratory or resistance training activities. The resistance exercise sessions will progressively become more difficult as the participants adapt to the initial training stimuli. Following the initial training week, which will be deliberately sub-maximal and relatively low in intensity, we will aim to make the level of difficulty for each exercise approximately 7 out of 10 on the RPE scale. This is to ensure the resistance training sessions are challenging and provide appropriate adaptation. To achieve this, the repetitions (reps) and sets will be progressively overloaded until each participant reaches a maximum volume of three sets for 15 repetitions. Based on previous experience, once a participant performs more than three sets of 15 repetitions per set, boredom quickly sets in. Thus, once the maximum reps and sets volume has been achieved, there will be an incremental change of resistance bands (e.g., change from light to medium). For the resistance training sessions, the researcher will use the participants’ RPE scores for each exercise to adjust the number of reps either up or down by two. If the RPE was rated 9 or above, then the number of reps would be reduced by two reps. If the RPE was rated 7 or below, then the number of reps would be increased by two reps. If the participant was only able to complete the minimum target and had an RPE of 9 or more, then their number of reps would not be changed until their RPE score was 7 or below. The minimum exercise target is three sets of each exercise, and there are 10 exercises altogether. Muscular endurance is expected to change over the course of the resistance training program. Strategies for improving adherence: The student investigator will have weekly check-in sessions with each participant via video-conference calls in Microsoft Teams to ensure they adhere to the exercise programme and continue to receive support through feedback on their activity level. Participants will also receive reminders via Outlook for their cardiorespiratory and resistance training.