Join a University of Colorado research study investigating how exercising in the morning compared to exercising in the evening may affect your body weight, body composition, fitness, and other health outcomes.


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Exercise
Research Study
COMIRB #21-3094

Body Mass Index of 25-40 kg/m2
Exercise at the University of Colorado Anschutz Medical Campus
In Generally Good Health
Non-Smoker
18 - 55 Years Old
Fast Facts
About Our Research Study
This research study is designed to explore how morning versus evening exercise training affects body weight, body composition, fitness, and other health outcomes.

What is the best time of day to exercise? Do early birds get the most health benefit or is it the night owls?

This research study is investigating how exercising in the morning or evening affects body weight, body composition, fitness, metabolic health, sleep, eating patterns, and activity patterns. Research study participants will be randomized to exercise either in the morning or the evening.

Join our University of Colorado exercise research study and receive complimentary access to the Anschutz Health and Wellness Center Fitness Center, a free 13-month structured exercise program, and free assessments of your metabolism, body composition, and fitness level.
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Additional Information
Why is this research study being done?
The primary purpose of this research study is to understand how morning versus evening exercise affects body weight and body composition.
Is this research study for me?
You may qualify for this research study if you meet the following criteria.

Eligibility Criteria:

  • Adult between 18 and 55 years old
  • Generally healthy without diabetes or heart disease
  • Non-smoker
  • Not currently exercising more than 150 minutes per week
  • Overweight or Obese (BMI between 25.0 and 40.0 kg/m2) Calculate your BMI here
  • Live or work within 30 minutes of the University of Colorado Anschutz Medical Campus https://www.cuanschutz.edu/
*The criteria listed above is only a partial list of all the requirements to participate in this research study. Only a clinical research staff member can determine eligibility.

What will happen if I participate in the study?
  • You will be asked to attend several screening visits to make sure you are eligible to be in the research study and that it is safe for you to participate.
  • If you are eligible for the study, you will be asked to gradually increase your level of aerobic exercise over 3-4 months and maintain this higher level of aerobic exercise for the rest of the 13-month study.
  • You will be randomly assigned to one of the two groups. Both groups will receive the same weekly aerobic exercise goal. One group will complete all of their exercise sessions in the morning (6-9 AM), another will complete all of their exercise sessions in the late afternoon/evening (4-7 PM). You will not get to choose which group you are placed into, and you will not be able to change groups during the study.
  • You will be required to attend regular exercise sessions at the University of Colorado Anschutz Health and Wellness Center in Aurora, CO.
  • You will undergo measurements of body weight, body composition, cardiorespiratory fitness, and metabolic rate. You will also be asked to periodically wear an activity monitor and record your food intake. You will be asked to complete questionnaires about your eating patterns, sleep, and mood. You will have your blood drawn and urine samples will be collected.
Why should I participate?
  • Free 13-month membership to The Anschutz Health and Wellness Fitness Center, a 94,000 square foot exercise facility with cardiovascular and strength training equipment, group exercise classes, and steam room/sauna, on The University of Colorado Anschutz Medical Campus.
  • See facility at: http://www.anschutzwellness.com/fitness
  • A 7-month monitored exercise program at the Anschutz Health and Wellness Center Fitness Center
  • Behavioral support for exercise from an exercise specialist for 13 months.
  • Assessment of body composition, resting metabolic rate, cardiometabolic health parameters, fitness, physical activity level, and sleep.
  • Financial compensation provided.
Will it cost me anything to participate in this study?
  • Generally, there is no cost for you to participate in the research study.
  • If you do not have proper exercise footwear or attire, you may need to purchase them prior to participating.
  • You may need to pay for parking during research study visits. Parking in the visitor lots near the Anschutz Health and Wellness Center Fitness Center is $1 per hour on weekdays and a flat rate of $1 on weekends and after 4 PM on weekdays.