Exercise Snacking and Cardiometabolic Health

Regular physical activity reduces the risk of cardiovascular disease, type 2 diabetes, obesity, and other chronic health conditions. Despite these well-established benefits, many young adults do not achieve recommended levels of physical activity. Commonly reported barriers include limited time, competing academic or work demands, and difficulty maintaining structured exercise programs.

Exercise snacking, defined as accumulating multiple brief bouts of moderate-to-vigorous physical activity throughout the day, has emerged as a potential strategy for increasing physical activity while minimizing many of the barriers associated with traditional exercise programs. Although short bouts of physical activity have demonstrated favorable acute physiological effects, relatively few randomized controlled trials have evaluated whether exercise snacking produces sustained improvements in objectively measured physical activity, physical fitness, cardiometabolic health, and psychological outcomes in free-living young adults.

The purpose of this study is to determine whether a 12-week exercise snacking intervention improves physical activity behavior, aerobic fitness, cardiometabolic health, exercise motivation, affective responses to physical activity, and psychological well-being compared with a usual behavior control group. Participants will be randomly assigned to either an exercise snacking intervention or a control condition. Following completion of the intervention, participants will be observed for an additional 12 weeks to evaluate the maintenance of behavioral and physiological changes after structured support is withdrawn.

The primary objectives are to determine whether exercise snacking increases objectively measured physical activity and improves aerobic fitness. Secondary objectives are to evaluate changes in body composition, blood pressure, fasting cardiometabolic biomarkers, exercise motivation, affective responses to exercise, and psychological well-being. Exploratory analyses will examine whether changes in motivation and affective responses are associated with long-term maintenance of physical activity during the follow-up period.

This study will contribute to the growing evidence regarding practical, scalable approaches for increasing physical activity among young adults and may help inform future lifestyle interventions and public health recommendations aimed at promoting long-term engagement in regular physical activity

Inclusion criteria

• Age 18-60 years.
• Body mass index (BMI) ≥18.5 kg/m².
• Insufficiently physically active, defined as generally not meeting current physical activity guidelines for moderate-to-vigorous physical activity.
• Able to safely participate in moderate-to-vigorous physical activity as determined by study screening procedures, including completion of the Physical - Activity Readiness Questionnaire (PAR-Q+) and health history review.
• Willing and able to provide written informed consent.
• Willing to complete all study visits, wear activity monitors, and comply with study procedures.

Exclusion criteria

• Known cardiovascular, pulmonary, metabolic, neurological, orthopedic, or other medical conditions that would make participation in moderate-to-vigorous physical activity unsafe.
• Resting heart rate >100 beats/minute at screening.
• Resting blood pressure >160/100 mmHg at screening.
• Clinically significant electrocardiogram (ECG) abnormalities identified during screening that require medical evaluation.
• Current participation in regular structured physical activity that meets or exceeds recommended physical activity guidelines.
• Physical limitations or injuries that preclude safe participation in the intervention or fitness testing.
• Moderate-to-severe psychological distress or other mental health concerns identified during screening that require referral or would make study participation inappropriate.
• Pregnancy or any other condition judged by the investigators to make participation unsafe or interfere with completion of study procedures.