Sitting Interruption and Whole-body Cardiovascular Health

Inclusion Criteria: * Aged between 30-60 years * Insufficiently active: self-reported exercise \<90 minutes per week for the past 3 months * Sedentary: self-reported sitting \>8 hours per day * Self-reported ability to walk 4 blocks and climb 2 flights of stairs * Possession of cellular phone able to receive text messages Exclusion Criteria: * Use of assisted-walking devices * Comorbid condition that would limit the ability to reduce sedentary behavior (e.g., musculoskeletal condition, current chemotherapy) * Plans for major surgery within next 3 months * Recent history (\<1 year) of ischemic heart disease, chronic heart failure, stroke, or chronic kidney disease * Recent (\< 1 year) or planned bariatric surgery * Systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥100 mmHg * Current or recent (within last 6 months) pregnancy; current or recent (within last 3 months) breastfeeding * Morbidly obesity (BMI \>40 kg/m\^2) or underweight (BMI \<18.5 kg/m\^2) * Use of anti-hypertensive drugs * Use of glucose-controlling medication * Heavy alcohol consumption (\>15 drinks per week)