Description of the study Forty individuals (20 men and 20 women) 18-35 years of age with normal resting BP (< 140/90 mmHg) will be enrolled in this study. Subjects should not be smokers, L-citrulline users or regular exercisers (defined as more than 120 min per week) in the last 6 months. The exclusion criteria will be any contraindication to exercise and medical conditions. Subjects with diverse ethnic backgrounds will be recruited from the Tallahassee metropolitan area by advertisement and direct communication.