Effect of Exercise on Appetite in Response to Meals

Study Design

Screening visit Before conducting the main experiments, the participants will attend a screening visit where consent will be obtained, and they will complete questionnaires to assess health, food preferences, and physical activity. The researchers will then measure the participants' height, weight, waist circumference, and body composition.

After the researchers confirm the eligibility criteria, participants will take part in two treadmill tests to establish maximum oxygen uptake test (V̇O2 max) (Broom et al. 2017).

Experimental design After the screening visit, the participants will complete three main experiments (control, short high-intensity exercise, and prolonged high-intensity exercise) in a counter-balanced design. All experiments began at ~0930, following an overnight fast of at least 10 hours. Participants will consume a prescribed meal in the evening before each main experiment. Following this meal, participants are only allowed to drink water until the start of the main experiments.

At the beginning of the exercise conditions, participants will run on the treadmill for 10 minutes (short) or 30 minutes (prolonged) at a speed estimated to elicit a 75% V̇O2 peak, followed by rest in the laboratory. In the control condition, the researchers will follow the same protocols except that the participants will not perform any exercise. The participants will have a standardized meal after exercise and then an ad libitum buffet meal afterward.

During each experiment, the researchers will assess appetite ratings using 100 mm visual analog scales (Flint et al. 2000). The researchers will also collect blood samples to examine ghrelin, peptide YY, glucagon-like peptide 1, and possibly other blood-borne measures.

Inclusion criteria

• Males aged 18 years or older.
• Have stable body mass for at least six months (within ±2 kg).

Exclusion criteria

• Females
• People who are younger than 18 or older than 65 years old.
• Have food allergies.
• Have significant contraindications to exercise (e.g., an injury that would inhibit running).
• Smoking.
• Suffering from metabolic health issues, e.g., history of diabetes, cardiovascular disease, or eating disorders.