Aerobic fitness: Oxygen uptake (VO2) was measured from expired air samples on a breath-by-breath basis during cycle ergometry. We verified maximal effort when 2 of 3 criteria were met [Balady et al. 2010]: 1) a plateau in VO2 between two or more workloads, 2) respiratory exchange ratio ≥1.10, and 3) HR > 85% of the age predicted HRmax.