Figure Percent change in cardiorespiratory fitness (VO2max) according to group categorization in the moderate and vigorous intensity conditions. For the moderate intensity condition, participants were divided into the following three groups: < 90 min per week (“LOW”), 90 to 149 min per week (“MEDIUM”), and ≥ 150 min per week (“HIGH”). As presented in Panel A, cardiorespiratory fitness did not vary by group category in the moderate intensity condition. For the vigorous intensity condition, the three groups were the following: < 60 min per week (“LOW”), 60 – 119 min per week (“MEDIUM”), and ≥ 120 min per week (“HIGH”). As shown in Panel B, the HIGH (mean ± SE = 10 ± 2.0%) and MEDIUM groups (6 ± 2.1%) demonstrated significantly greater improvements in fitness compared to the LOW group (−3 ± 2.4%) in the vigorous intensity condition. This trial was conducted in Gainesville, FL between 1999 and 2003.