Energy Expenditure & Activity During & After Exercise-Induced Weight Loss - Full Text View

Sponsor:	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Information provided by:	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
ClinicalTrials.gov Identifier:	NCT00622310

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:	Randomized, Open Label, Parallel Assignment
Official Title:	Energy Expenditure & Activity During & After Exercise-Induced Weight Loss

Resource links provided by NLM:

MedlinePlus related topics: Exercise and Physical Fitness Obesity Weight Control

U.S. FDA Resources

Further study details as provided by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK):

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 2010
Estimated Primary Completion Date:	August 2010 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
1: 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.	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.
2: 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.	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.

Arms

Assigned Interventions

1: 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.

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.

2: 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.

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.

Contacts and Locations

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

Contacts

Contact: Edward L Melanson	(303) 315-4087 ext 7	EXWTLOSS@uchsc.edu
Contact: Amber A Carlson	(303) 315-4087 ext 7	EXWTLOSS@uchsc.edu

Locations

United States, Colorado
University of Colorado, School of Medicine	Recruiting
Aurora, Colorado, United States, 80045
Contact: Edward L Melanson 303-315-4087 ext 7 EXWTLOSS@uchsc.edu
Principal Investigator: Edward L Melanson, Ph.D.

Sponsors and Collaborators

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

More Information

No publications provided

Responsible Party:	University of Colorado, Denver, School of Medicine, Division of Endocrinology ( Edward L. Melanson, Ph.D. )
Study ID Numbers:	DK77088
Study First Received:	February 21, 2008
Last Updated:	August 6, 2009
ClinicalTrials.gov Identifier:	NCT00622310 History of Changes
Health Authority:	United States: Federal Government; United States: Institutional Review Board

Additional relevant MeSH terms:

Body Weight
Signs and Symptoms
Obesity
Weight Loss

Body Weight Changes
Nutrition Disorders
Overweight
Overnutrition

ClinicalTrials.gov processed this record on February 08, 2010