Effects of Inspiratory Muscle Exercise on Health

Acute Effects of Intermittent Inspiratory Muscle Training on Blood Glucose and Vascular Function Responses

The purpose of this study is to investigate whether inspiratory muscle training has an immediate effect on energy expenditure, heart rate, blood glucose, blood pressure, and arterial stiffness in healthy adults, obese adults, and adults with type 2 diabetes.

Participants will be asked to complete two trials involving intermittent exercise, which will include eupnea and inspiratory muscle training (IMT), as well as a resting control condition, in a randomized crossover study design. The trials will be separated by a minimum of 48 hours and will be completed within a 7-day period. Throughout all trials, participants will be required to remain relaxed and seated on an adjustable examination bed. For the IMT intensity, participants will utilize an inspiratory muscle training device (PowerBreathe Plus, Powerbreathe International Ltd., UK) and adjust the resistance to a level at which breathing continuously for 20 breaths is perceived as "somewhat hard" (RPE = 13), according to the Rating of Perceived Exertion (RPE) scale. This will take place during a 3.5-hour oral glucose tolerance test (OGTT). During the trials, participants may watch television or read; however, typing on a laptop or computer will be prohibited.

Inclusion Criteria

• Healthy adults, obese adults and adults with type 2 diabetes
• Aged between 20 to 45 years
• Weight stable for more than 3 months (no change in weight +/- 3%)
• Non-smoker
• Non-highly trained athletic team members
• Normal lifestyle patterns

Exclusion Criteria

• Personal history of/existing hypertension, respiratory infectious disease, cardiovascular disease, metabolic disease
• Taking medications that may influence lipid or carbohydrate metabolism or immune system function