Progressive Metabolic Adaptations to Low Intensity Exercise Training and Weight Loss

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2013 by University of Michigan
Sponsor:
Collaborator:
Information provided by (Responsible Party):
JEFFREY F HOROWITZ, University of Michigan
ClinicalTrials.gov Identifier:
NCT01452074
First received: October 11, 2011
Last updated: June 17, 2013
Last verified: June 2013
  Purpose

the investigators first aim is to determine the effect of low intensity exercise (without weight loss) on insulin sensitivity, muscle lipid metabolism, and factors regulating these processes in skeletal muscle after 1 day, 2 wks, 12 wks of training, and again after 3 days without exercise in obese adults. the investigators second aim is to determine the effect of combining low intensity exercise training with 10% weight loss on insulin sensitivity, muscle lipid metabolism, and factors regulating these processes in skeletal muscle.

Although a single 40 minute session of exercise at a low exercise intensity will not improve insulin sensitivity, the investigators anticipate adaptations after two weeks of exercise training (6 session/wk; 12 session total) will improve insulin sensitivity and be accompanied by a reduction in fatty acid intermediates and a reduction in markers for pro-inflammatory activation in muscle. the investigators anticipate changes in insulin sensitivity, fatty acid partitioning, and pro-inflammatory markers the day after the last session of a 12 wk training program (without weight-loss) will be similar to that measured after 2 weeks of training. the investigators anticipate insulin sensitivity, accumulation of fatty acid intermediates, and pro-inflammatory activation will be markedly improved after 10% weight loss when measured the day after exercise. the investigators would expect the improvements in Insulin sensitivity, accumulation of fatty acid intermediates, and markers of inflammatory stress will be significantly attenuated when measured 3 days after the most recent exercise session, but beneficial effects of 10% weight loss on these metabolic endpoints will persist when compared with before weight loss.


Condition Intervention
Obesity
Other: Exercise Training
Other: Weight Loss with continued Exercise Training

Study Type: Interventional
Study Design: Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science

Resource links provided by NLM:


Further study details as provided by University of Michigan:

Primary Outcome Measures:
  • Insulin Sensitivity [ Time Frame: 2-3 hours ] [ Designated as safety issue: No ]
    A hyperinsulinemic-euglycemic clamp will be used to assess peripheral insulin sensitivity


Secondary Outcome Measures:
  • Resting Metabolic Rate [ Time Frame: 20-30 min ] [ Designated as safety issue: No ]
  • Meal Tolerance Test [ Time Frame: 2-3h ] [ Designated as safety issue: No ]

Estimated Enrollment: 16
Study Start Date: July 2011
Estimated Study Completion Date: April 2016
Estimated Primary Completion Date: April 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Exercise Training with Weight Loss

During the first 12 weeks of the study, subjects will adhere to an exercise training program while maintaining their original body weight. The exercise training program will entail the following: 40min/session, ~50% of their maximal aerobic capacity (approximately 100-110 beats per min), 5-6 days/week

After the first 12 weeks in the study, subjects will continue with the same exercise program, but then they will be placed on a reduced calorie diet until they lose exactly 10% of their original body weight

Other: Exercise Training
During the first 12 weeks of the study, subjects will adhere to an exercise training program while maintaining their original body weight. The exercise training program will entail the following: 40min/session, ~50% of their maximal aerobic capacity (approximately 100-110 beats per min), 5-6 days/week
Other: Weight Loss with continued Exercise Training
After the first 12 weeks in the study, subjects will continue with the same exercise program, but then they will be placed on a reduced calorie diet until they lose exactly 10% of their original body weight

  Eligibility

Ages Eligible for Study:   18 Years to 45 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • body mass index [BMI]: 30-45 kg/m2; All women must be pre-menopausal; Non-exerciser (no regularly planned exercise/physical activity)

Exclusion Criteria:

  • Hematocrit ≤ 34%; Fasting plasma glucose concentration ≥ 125 mg/dL; Weight instability ≥ ±5 lbs in past month; Taking medications known to affect lipid and/or glucose metabolism; evidence and/or history of cardiovascular or frank metabolic diseases; pregnancy or actively breast feeding
  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: NCT01452074

Contacts
Contact: Suzette Howton, RD 734-647-9850 suzetter@med.umich.edu

Locations
United States, Michigan
Michigan Clincal Research Unit Recruiting
Ann Arbor, Michigan, United States, 48109
Contact: Suzette Howton, RD    734-647-9850    suzetter@med.umich.edu   
Principal Investigator: Jeffrey F Horowitz, Ph.D.         
Sponsors and Collaborators
University of Michigan
Investigators
Principal Investigator: Jeffrey F Horowitz University of Michigan
  More Information

No publications provided

Responsible Party: JEFFREY F HOROWITZ, Associate Professor, Movement Science, School of Kinesiology, University of Michigan
ClinicalTrials.gov Identifier: NCT01452074     History of Changes
Other Study ID Numbers: R01 DK077966 - PA, R01DK077966
Study First Received: October 11, 2011
Last Updated: June 17, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by University of Michigan:
Insulin Sensitivity
Exercise Training
Weight Loss
Fat Metabolism

Additional relevant MeSH terms:
Obesity
Weight Loss
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Body Weight Changes

ClinicalTrials.gov processed this record on July 29, 2014