Effects of Breaking up Prolonged Sitting on Postprandial Cardiometabolic Disease Risk Markers in South Asian Adults

Effects of Breaking up Prolonged Sitting on Postprandial Cardiometabolic Disease Risk Markers in Normal Weight Versus Overweight and Obese South Asian Adults

The purpose of this study is to examine whether breaking up prolonged sitting with short regular bouts of walking can reduce blood sugar and cholesterol levels after eating, which are risk markers for Type 2 diabetes and heart disease. This study will compare these responses in normal-weight versus overweight/obese South Asian adults.

Participants will attend a preliminary testing session where height, weight, body fat and waist circumference will be measured. They will be familiarised with a motorised treadmill that will be used during the experimental visit below and will take part in an exercise test to determine a light-intensity walking speed for the experimental visit.

Participants will then attend two experimental visits in a random order:

1. Prolonged sitting (SIT): Participants will remain seated for 5 hours and instructed to reduce excessive movement.
2. Breaking up sitting with walking breaks (INT-SIT): Participants will rise from the seated position every 30 minutes throughout the experimental period to walk on a motorised treadmill at a light intensity for 5 minutes. After performing walking activity, they will return to the seated position. In addition, blood sample will be taken at the resting position just before each physical activity bout. The activity breaks will be undertaken on 9 occasions, providing a total of 45 min of light-intensity activity.

During each visit, blood pressure will be taken 11 times and blood samples will be taken 10 times. Participants will be given a breakfast and lunch meal to consume.

Inclusion Criteria:

• Self-identified South Asian ethnicity.
• Self-report sitting at least 7 hours per day.
• Normal weight, overweight or obese.

Exclusion Criteria:

• Unable to speak and read English.
• Contraindications to performing light-intensity walking.
• Diagnosed cardiovascular disease or diabetes.