Regulation of mitochondrial health in overweight and obese individuals may be impaired. The purpose of this study is to identify impairments in regulation of mitochondrial health within skeletal muscle and to determine if short-term exercise training (2-weeks) can reverse such impairments. The investigator's hypothesis is that pathways that serve to degrade poorly functioning mitochondria in overweight and obese individuals are down-regulated, but that short-term exercise training can restore these pathways to improve skeletal muscle mitochondrial function.

Inclusion Criteria:

• Age 18-45 years
• Body mass index (BMI) 18-45 kg/m2
• Sedentary (<1 hour of planned exercise per week)

Exclusion Criteria:

• Regular exercise (>1 hour of planned exercise per week)
• Smoking, tobacco or nicotine use within the last 1-year
• Fasting glucose >126mg/dL
• Hypertension (systolic pressure >140 mmHg or diastolic pressure >90 mmHg)
• Chronic metabolic or cardiovascular health conditions
• Pregnant, nursing, irregular menses or post-menopausal
• Lidocaine allergy
• Certain medications
• Physical limitations that prevent safe or successful exercise completion
• Diminished capacity for consent