None listed
Conditions
Brief summary
It is well-established that exercise is associated with a variety of physical and psychological benefits; however, certain post-exercise behaviours, such as consuming excess or unhealthy foods in the aftermath of an exercise session, may counteract some of these benefits. The effect of exercise on food consumption appears to be influenced by both exercise format (e.g., overall intensity and structure of exercise) as well as psychological experiences during exercise. In relation to exercise format, it has been shown that high-intensity intermittent exercise, relative to traditional exercise performed at a moderate-intensity, suppresses appetite and energy intake at the post-exercise period. As for psychological experiences of exercise, it appears that more autonomously motivated individuals may be less likely to endorse the use of food rewards post-exercise. Despite this evidence, numerous issues with this relationship remain unresolved. For instance, no previous work has explored the interactive effects of exercise format and psychological experiences during exercise on subsequent food choices. As such, the aim of this research is to examine which exercise conditions, both in terms of the format and psychological experiences of exercise, have the strongest influence on post-exercise appetite and food intake.
Interventions
Using a mixed-subjects yoked 2 (need-support) x 2 (exercise format) factorial design, participants will be allocated to one of two conditions: need-support or no need-support. Within each condition, participants will complete two types of exercise on separate visits: high-intensity intermittent exercise and moderate-intensity continuous exercise.
Need-support will be provided to participants randomised to the support group through the experimenter who holds a bachelor's degree with Honours and
Using a mixed-subjects yoked 2 (need-support) x 2 (exercise format) factorial design, participants will be allocated to one of two conditions: need-support or no need-support. Within each condition, participants will complete two types of exercise on separate visits: high-intensity intermittent exercise and moderate-intensity continuous exercise. Need-support will be provided to participants randomised to the support group through the experimenter who holds a bachelor's degree with Honours and has experience conducting research experiments which involve psychological manipulations to the delivery of exercise (e.g., Beer et al., 2017, Medicine & Science in Sports & Exercise, 49, 10, 2110-2118). Training in delivery of need-support has also been provided by members of the research team who are well-versed in the field of exercise motivation (which includes delivery of need-supportive exercise conditions). For example, autonomy-support will be facilitated by providing clear rationales and benefits of the particular type of exercise, acknowledging the feelings of participants towards the exercise, offering choices where possible, such as of the music accompaniment and the order in which participants complete the two exercise conditions (i.e., whether they complete the moderate-intensity continuous exercise or high-intensity intermittent exercise session first) , and using language which is indicative of choice (e.g., “you’re in charge today”). Competence will be supported by providing clear instructions and expectations, offering positive feedback, guidance, and support, and encouraging goal setting. Relatedness will be provided by interacting with warmth and care, offering empathy where appropriate, and displaying appreciation and concern for participants’ well-being. To ensure fidelity of the need-support delivery, participants will complete a questionnaire to assess the instructor's delivery of need-support. Additionally, a modified version of this questionnaire will be completed by two independent observers, who are blind to the experimental conditions, at a number of the experimental sessions. The high-intensity intermittent exercise will consist of a one-off bout of 30 minutes of cycling alternating very high-intensity efforts performed at a ratio of 1:4 (15 s at a power output equivalent to ~170% peak oxygen consumption; VO2peak) with an active recovery period (60 s at a power output of ~32% VO2peak) between efforts. All sessions will be directly supervised with heart rate and power output monitored to ensure adherence to the prescribed workload. Following the exercise bout, participants will be provided with an ad libitum test meal to assess post-exercise energy intake. Details of this meal are provided in section 4 (Primary outcome 1).
Sponsors
Dr Kym Guelfi
Study design
Allocation
Randomised controlled trial
Intervention model
Factorial
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
Participants will be eligible for participation if they are aged between 18 and 40 years and physically inactive, defined as performing less than 75 minutes of moderate to vigorous physical activity per week.
Exclusion criteria
- History of medical conditions such as diabetes, hyperlipidaemia - History of eating disorders known to affect appetite or restrained eaters (measured as scoring above 3.5 on the Dutch Eating Behaviour Questionnaire) - Diet status which may interfere with food intake (e.g., on a weight-loss diet) - Currently taking medication which could interfere with energy intake, appetite, or exercise - Any known food allergies or dietary requirements (e.g., vegan) - Injury or condition preventing exercise
Outcome results
None listed