Physical activity was measured using the international physical activity questionnaire (IPAQ) [11]. The IPAQ is a self-administered 4-item questionnaire assessing the frequency and duration of moderate and vigorous intensity physical activity in the past seven days. Examples of moderate physical activity include brisk walking, bicycling, vacuuming, gardening, or anything else that causes some increase in breathing or heart rate. Vigorous physical activity includes running, aerobics, heavy yard work, or anything else that causes large increases in breathing or heart rate. The IPAQ has acceptable test-retest reliability and concurrent validity. Criterion validity has been adequately demonstrated when measured against accelerometry [11]. Similar to the methods reported in Puterman et al. [12] and Kim et al. [8], and considering the evidence for recall bias in physical activity measurement [13], we dichotomize physical activity into two groups based on habitual exercise levels (none versus moderate to vigorous).