A goal of this study is to use a novel methodology to determine whether insulin resistance in women with polycystic ovary syndrome (PCOS) is related to the accumulation of proteins with modifications. This could lead to future research to determine if these modifications interfere with their proper function. Additionally, the investigators will determine how protein quality is affected by exercise training. Aerobic exercise enhances the endogenous oxidant buffering systems which may minimize oxidative damage to proteins. The investigators propose that aerobic exercise minimizes the accrual of modified proteins by increasing the synthesis of new proteins, but also by increasing the degradation and removal of old and damaged proteins. Based on our previous studies the investigators observed that insulin affects plasma protein synthesis and aerobic exercise improves insulin sensitivity not only in muscle but also in liver. The investigators therefore propose that aerobic exercise and related increase in insulin sensitivity (and decline in insulin levels) will reduce accumulation of old and modified skeletal muscle and plasma proteins leading to improved function.

Inclusion Criteria:

1. BMI between 25 kg/m2 and 40 kg/m2
2. Fasting blood glucose < 126 mg/dL
3. Diagnosed with PCOS as outlined by the Rotterdam criteria
4. Insulin resistant as determined by a 3 hour oral glucose tolerance test

Exclusion Criteria:

1. Serum creatinine ≥1.5 mg/ dL.
2. Serum transaminase elevation ≥ 3 times the upper limit of normal range
3. Use of systemic glucocorticoids
4. Use of oral anticoagulation
5. Pregnancy