VO2AT was determined using the V-slope method. By measuring changes in oxygen and carbon dioxide content in the expired air, VO2AT may be determined based on the slope of the relationship between carbon dioxide output (VCO2) and oxygen uptake (VO2) during exercise. Then, ergospirometry data were used to determine heart rate at which anaerobic threshold was obtained and this value was used as the target heart rate during exercise training. Anaerobic threshold was determined independently by two physicians who regularly performed CPET.