Overview

This trial is active, not recruiting.

Condition obesity
Treatment walking exercise
Sponsor University of Colorado, Denver
Collaborator National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Start date September 2007
End date March 2016
Trial size 40 participants
Trial identifier NCT00622310, 07-0402, R01DK077088

Summary

This project is aimed at determining whether an exercise-based weight loss intervention causes a compensation in some component of energy expenditure such that the increase in measured energy expenditure is less than the added exercise. The study will compare two separate exercise interventions to determine if this is influenced by exercise intensity.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Intervention model parallel assignment
Masking open label
Arm
(Experimental)
Subjects in the EX group will perform supervised exercise 5 d/wk. Exercise will consist primarily of walking on an inclined motor-driven treadmill, but alternate activities will be permitted for 20% of the total exercise sessions (1 of 5 days). Exercise sessions will be preceded by a 5 min warm-up performed at a HR corresponding to 40% of VO2max. The initial exercise duration and intensity at baseline will be 20 minutes at an intensity that elicits a heart rate (HR) corresponding to 60% of VO2max. The target EE will be achieved by a gradual progression of exercise duration and intensity over the first 8 weeks of the exercise program. The target exercise intensity will be the workload corresponding to 75% of VO2max.
walking exercise
Subjects will be randomly assigned to either a structured, vigorous-intensity endurance exercise training program or an intermittent, low-intensity exercise program. Individualized exercise prescriptions will be designed to target an increase of 2500 kcal/wk, and the theoretical weight loss will be approximately 15 pounds (~6.8 kg) during the 6 month intervention.
(Experimental)
Subjects in the WALK group will also perform exercise 5 d/wk. Exercise will consist exclusively of walking on level grades, and will be prescribed in two equal duration bouts each day. Subjects in the WALK group will be individually prescribed a walking program based on the EE during moderate intensity walking. The target exercise intensity will be walking speeds corresponding 45% of VO2max.
walking exercise
Subjects will be randomly assigned to either a structured, vigorous-intensity endurance exercise training program or an intermittent, low-intensity exercise program. Individualized exercise prescriptions will be designed to target an increase of 2500 kcal/wk, and the theoretical weight loss will be approximately 15 pounds (~6.8 kg) during the 6 month intervention.

Primary Outcomes

Measure
Total daily energy expenditure, assessed using doubly labeled water
time frame: 6 months

Secondary Outcomes

Measure
Total daily activity thermogenesis
time frame: 6 months
Body weight and composition
time frame: 6 months

Eligibility Criteria

Male or female participants from 18 years up to 55 years old.

Inclusion Criteria - Body mass index (BMI) 30-35.0 kg/m2 - Age 18-45 years - Weight stable (<2 kg weight fluctuation during previous 6 months) - No regular exercise (> 1 bout of exercise/wk or participation in any sporting activities > 1 hr/wk) - No self-report of acute or chronic disease (diabetes, heart diseases, and joint problems in particular) - No current use of prescribed medications - No plans to relocate within the next year - No plans for extended travel (> 1 week) within the next 6 months - No tobacco use - For females - No evidence of amenorrhea (Regular menstrual cycles of 21-35 days) - Pre-menopausal status (self-report, to be confirmed during screening) - Pregnancy or lactating within the past year - No pregnancy or planned pregnancies; sexually active women of childbearing potential may be enrolled if they have had a tubal ligation or use one of the following means of contraception: condom, diaphragm, oral or implanted contraceptives, or intrauterine device. Women in exclusive relationships with male partners who have had a successful vasectomy will not be required to use any additional means of birth control. Exclusion Criteria: Conditions that do not meet the Inclusion Criteria listed.

Additional Information

Official title Energy Expenditure & Activity During & After Exercise-Induced Weight Loss
Principal investigator Edward Melanson, PhD
Description The primary aim of this proposed study is to determine how total daily activity thermogenesis (TDAT) and total daily energy expenditure (TDEE) are regulated in obese humans attempting to lose weight and maintain weight loss through exercise. Two exercise interventions will be compared; a structured aerobic exercise program and a walking program. EAT will be verified, and NEAT, TDAT, and TDEE will be measured using state-of-the-art technologies. Subjects will be studied during a 6 month intervention period and then during a 6 month follow-up period. It is hypothesized that the walking program will have more favorable effects on TDAT and TDEE during both the intervention and follow-up periods. If our hypotheses are correct, then data from the proposed study could be used to improve the effectiveness of exercise-based weight loss and weight loss maintenance programs.
Trial information was received from ClinicalTrials.gov and was last updated in January 2016.
Information provided to ClinicalTrials.gov by University of Colorado, Denver.