Obesity is associated with reduced adenosine triphosphate (ATP) turnover in skeletal muscle, a condition that can impair muscle metabolism. The proposed research will discover mechanisms responsible for decreased content in mitochondrial proteins as well as in protein β-F1-ATPase, which is directly responsible for ATP assembly, in the muscle of obese individuals. This research will further examine the effectiveness of interventions, such as increased plasma amino acid availability and exercise, to increase the rate of production of mitochondrial proteins as well as that of β-F1-ATPase in the muscle of obese individuals. The findings will help to develop appropriate interventions to improve muscle ATP turnover and metabolism in obese people.

Inclusion criteria:

1. Body mass index (BMI): lean, 19-26 kg/m2; obese, 30-40 kg/m2
2. Availability of transportation
3. Ability to sign informed consent form

Exclusion criteria:

1. Medication or supplements (i.e. amino acids, protein) known to affect protein metabolism
2. Presence of acute illness
3. History of liver disease
4. Uncontrolled metabolic disease
5. ECG documented abnormalities, atrial fibrillation, history of syncope, limiting or unstable angina, or congestive heart failure
6. Chronically elevated blood pressure (systolic, >140 mmHg; diastolic, >100 mmHg)
7. Cardiac pacemaker or other medical device implanted in the body
8. Low hemoglobin or hematocrit
9. Current participation in a weight-loss regimen, including extreme dietary practices
10. Smoking
11. Use of anabolic steroids or corticosteroids (within 3 months)