Sedentary Behavior, Cardiovascular Function, and Sleep
Sedentary Behavior, Cardiovascular Function, and Sleep
This is a randomized crossover study that will examine how sedentary behavior (decreased
 physical activity) over time and returning to normal physical activity affects cardiovascular
 health (i.e. heart rate and blood pressure) and sleep quality/duration.
PRIMARY OBJECTIVES:

 1. To test the hypothesis that two weeks of sedentary behavior will progressively impair
 vascular endothelial function 2: To test the hypothesis that increasing sedentary behavior
 will decrease total sleep duration and sleep efficiency.

 3: To test the hypothesis that two-weeks of sedentary behavior will progressively increase
 24-h blood pressure and reduce nocturnal blood pressure dipping.

 OUTLINE:

 Participants will become more inactive and also maintain their activity (in randomized order)
 and also come in for 3-hour uninterrupted sitting visits. Cardiovascular, activity, and sleep
 measures will be taken throughout.
Inclusion Criteria:

 -  Men and women ages 30-60y

 -  Lean and overweight (BMI 18.5-40 kg/m2)

 -  No acute, chronic, or debilitating medical conditions

 -  No prescription/non-prescription medications or drugs of abuse

 -  Non-smoker

 -  Average level of daily physical activity (8,000-12,499 steps/day)

 -  Persons who fit all the above criteria and are suitable based on a medical history and
 health habits questionnaire, sleep profiling questionnaire, and electrocardiogram and
 clinical biochemical screening tests of blood and urine may be eligible to
 participate.

 Exclusion Criteria:

 -  Persons with any acute, chronic, or debilitating medical condition except
 pre-hypertension and/or mild to moderate sleep apnea will be excluded.

 -  Persons with any symptoms of acute or active illness (e.g. fever, leukocytosis) will
 be excluded.

 -  Persons with a history of severe psychiatric illness or psychiatric disorders will be
 excluded.

 -  Persons with a history of regular night/or rotating shift work, or who have traveled
 more than three time zones during the one month prior to the study will be excluded.

 -  Pregnant women, decisionally impaired adults, and prisoners will be excluded.