The purpose of this study is to test the effects of exercise on cocaine use, fitness, and cravings for cocaine and nicotine. This study is part of an effort to develop treatments for cocaine abuse.

This proposal represents an important research effort with considerable public health significance in that it will provide detailed behavioral and physiological data for a non-pharmacological intervention to treat stimulant addiction. Regular exercise is known to promote better mental and physical health, however the effects of exercise on cocaine use and craving in cocaine-dependent individuals has not been previously assessed. The Specific Aims include: 1) To evaluate the effects of regular exercise (running and walking) versus placebo (sitting) on basic fitness measures; 2) To evaluate the effects of exercise on objective and subjective measures of cocaine and nicotine use and craving. Participants will also receive a total of 12 sessions of a standardized series of computerized cognitive behavioral therapy (CCBT) modules, which are specifically designed for the treatment of cocaine addiction.

Inclusion Criteria:

In order to participate in the study, participants must:

• 1. Be English-speaking volunteers between 21-55 years of age
• 2. Be cocaine-dependent and nicotine-dependent (>10 cigarettes/day and FTND >4)
• 3. Be seeking treatment for cocaine dependence
• 4. Have vital signs as follows: resting pulse between 50-90 bpm, supine blood pressures between 85-150 mmHg systolic and 45-90 mmHg diastolic
• 5. Have a breathalyzer test indicating an undetectable blood alcohol level
• 6. Have a medical history and brief physical examination demonstrating no clinically significant contraindications for study participation, in the judgment of the admitting physician and the PI. Most relevant, assessments will include the participants' general health and suitability for inclusion in a rigorous exercise program.

Exclusion Criteria:

Potential participants will be excluded if any of the following apply:

• 1. Have neurological or psychiatric disorders, as assessed by MINI, such as: a. current major depression; b. lifetime history of schizophrenia, other psychotic illness, or bipolar illness; c. current organic brain disease or dementia assessed by clinical interview; d. current psychiatric disorder as assessed by the MINI including history of suicide attempts within the past three months and/or current suicidal ideation/plan
• 2. Meet DSM-IV criteria for abuse or dependence on other drugs, except for cocaine or nicotine
• 3. Have any of the conditions defined by the American College of Sports Medicine (2006) as "absolute contraindications to exercise testing"
• 4. Have evidence of clinically significant heart disease or hypertension
• 5. Have evidence of clinically significant or unstable medical illness including: neuroendocrine, autoimmune, renal, hepatic, or active infectious disease
• 6. Be pregnant or nursing. All females must provide a negative pregnancy urine test
• 7. Currently use alpha or beta agonists, theophylline, or other sympathomimetics
• 8. Currently engaged in an exercise regimen of similar intensity as those planned for investigation
• 9. Have any other illness, condition, or use of medications, which in the opinion of the PI and/or the study physician would preclude safe and/or successful completion of study.