Effect of Frequent Interruptions of Prolonged Sitting on Self-perceived Levels of Energy, Mood, Food Cravings and Cognitive Function

This study is designed to test the effects of six 5 minute microbursts of physical activity spread across the day as compared to either a sedentary control condition or a single 30 minute bout of moderate intensity physical activity on cognitive function, self-reported energy levels, aspects of eating behavior and measures of metabolic health. The primary hypotheses are:

1. Hourly 5 minute bouts of moderate intensity exercise during the day will increase afternoon cognitive function as compared to a no exercise condition.
2. Hourly 5 minute bouts of moderate intensity exercise during the day will increase afternoon cognitive function more than a single 30 minute AM bout.

Secondary exploratory hypotheses include

1. Hourly 5 minute bouts of moderate intensity exercise during the day will increase self-reported energy levels, reduce orexigenic appetitive measures and improve measures of metabolic health as compared to a no exercise condition.
2. Hourly 5 minute bouts of moderate intensity exercise during the day will increase self-reported energy levels, reduce orexigenic appetitive measures and improve measures of metabolic health more than a single 30 minute AM bout.

Inclusion Criteria:

1. All ethnic groups and both genders
2. Age: Lower age limit: 19 years; Upper age limit: 45 years
3. Body-mass Index: Lower BMI limit: 18.5 kg/m2; Upper BMI limit: 29.9 kg/m2
4. Willing to adhere to caffeine restrictions of no more than two 16 ounce beverages in the morning of each study day with no caffeine intake after 12:00pm on any of the three study days

Exclusion Criteria:

1. History of cardiovascular disease, including coronary artery disease, congestive heart failure, & unstable angina, or uncontrolled hypertension (>140/90 mm Hg)
2. Currently smoking or stopped smoking in the last 6 months
3. Medications affecting weight, energy intake, or energy expenditure in the last 6 months
4. Use of oral steroids
5. History of stroke or seizures, thyroid disease, type 1 or 2 diabetes, Cushing's syndrome, cerebrovascular, renal disease, hepatic disease, arrhythmias
6. Cancer requiring treatment in the past 5 years, with the exception of skin cancers other than melanoma
7. Infectious diseases: Self-reported HIV positivity or active tuberculosis
8. Inability to exercise for more than 30 minutes on a treadmill at moderate intensity
9. Currently pregnant, lactating or less than 6 months post-partum
10. History of a major psychiatric disorder including schizophrenia, bipolar illness or psychotic depression
11. Score of >25 on Beck Depression Inventory
12. No recreational drug use including marijuana in the past 1 year