Progressive Metabolic Adaptations to Low Intensity Exercise Training and Weight Loss
Study Details
Study Description
Brief Summary
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 or Disease | Intervention/Treatment | Phase |
|---|---|---|
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N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: 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
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Outcome Measures
Primary Outcome Measures
- Insulin Sensitivity [2-3 hours]
A hyperinsulinemic-euglycemic clamp will be used to assess peripheral insulin sensitivity
Secondary Outcome Measures
- Resting Metabolic Rate [20-30 min]
- Meal Tolerance Test [2-3h]
Eligibility Criteria
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
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Michigan Clincal Research Unit | Ann Arbor | Michigan | United States | 48109 |
Sponsors and Collaborators
- University of Michigan
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Investigators
- Principal Investigator: Jeffrey F Horowitz, University of Michigan
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- R01 DK077966 - PA
- R01DK077966