The purpose of this study was to find out the effects of aging on lipid metabolism by using Maximal Lipid Combustion Rate (MLCR), and on aerobic ability during exercise for three different age-groups. All subjects in this study were Japanese male workers (n = 206, range of age: 20-74 years old) who received health check-ups prior to performing the exercise stress test. They were categorized in three different groups according to age: (1) Age 20-39 (range of 20-39 years old: n = 53),(2) Age 40-59 (range of 40-59 years old: n = 100), (3) Age 60-74 (range of 60-74 years old: n = 53). Electrically braked cycle ergometer and gas analyzing system were used for this exercise stress test with gas analyzing (Ramp method: 20watt/min). Gas samples were collected by the Breath-by-Breath method, and analysis was done of Peak Vo2 (Peak Vo2), Peak Heart Rate (Peak HR), Maximal Lipid Combustion Rate (MLCR), Vo2 at Maximal Lipid Combustion Rate (MLCR-Vo2), and Vo2 at Anaerobic threshold point (AT-Vo2). Percentage rate of AT-Vo2 and Peak Vo2 (AT-Vo2/Peak Vo2), Percentage rate of MLCR-Vo2 and Peak Vo2 (MLCR-Vo2/Peak Vo2) were also calculated, and data values of each group were compared and analyzed to find the differences between age groups. Endurance ability is shown to lower with aging from the standpoint of data of Peak HR, Peak Vo2, AT-Vo2, MLCR-Vo2. However, the percentage rates of AT-Vo2/Peak Vo2 and MLCR-Vo2/Peak Vo2 increased with aging. It is suggested that any kind of function similar to homeostasis in the human body, that maintains Aerobic ability or helps to prevent it from decreasing, and lipid metabolism activation might be useful for the elderly.
