Energy Expenditure & Activity During & After Exercise-Induced Weight Loss

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborator:
Information provided by (Responsible Party):
University of Colorado, Denver
ClinicalTrials.gov Identifier:
NCT00622310
First received: February 21, 2008
Last updated: December 6, 2012
Last verified: December 2012
  Purpose

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.


Condition Intervention
Obesity
Behavioral: Walking exercise

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Official Title: Energy Expenditure & Activity During & After Exercise-Induced Weight Loss

Resource links provided by NLM:


Further study details as provided by University of Colorado, Denver:

Primary Outcome Measures:
  • Total daily energy expenditure, assessed using doubly labeled water [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Total daily activity thermogenesis [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  • Body weight and composition [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 40
Study Start Date: September 2007
Estimated Study Completion Date: August 2013
Estimated Primary Completion Date: August 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1 Exercise
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.
Behavioral: 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: 2 Walk
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.
Behavioral: 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.

Detailed 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.

  Eligibility

Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

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.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00622310

Locations
United States, Colorado
University of Colorado, School of Medicine
Aurora, Colorado, United States, 80045
Sponsors and Collaborators
University of Colorado, Denver
Investigators
Principal Investigator: Edward Melanson, PhD University of Colorado Division of Endocrinology, Metabolism, and Diabetes/Division of Geriatrics
  More Information

No publications provided

Responsible Party: University of Colorado, Denver
ClinicalTrials.gov Identifier: NCT00622310     History of Changes
Other Study ID Numbers: 07-0402, R01DK077088
Study First Received: February 21, 2008
Last Updated: December 6, 2012
Health Authority: United States: Federal Government
United States: Institutional Review Board

Additional relevant MeSH terms:
Weight Loss
Body Weight Changes
Body Weight
Signs and Symptoms

ClinicalTrials.gov processed this record on September 18, 2014