The effects of a 15-week quantitated training program were evaluated in nine men, 32 to 59 years old. All had been blind for 10 years or more but were otherwise in good health. They were sedentary with a stable activity pattern. Training sessions were held three times per week and consisted of four 3-minute exercise periods on a bicycle ergometer, each followed by a rest period of equal duration. Heart rates at the end of the fourth exercise period averaged 27 beats below individual maximal heart rates.Maximal oxygen uptake increased from 24.0 to 28.5 ml/kg × min or by 19%. Total heart volume and mean serum cholesterol decreased significantly, and psychological tests showed improvement.Five subjects continued exercising at the same intensity but only once weekly for another 14-week period. Mean maximal oxygen uptake decreased to 6% above the control level. Four subjects who discontinued training after 15 weeks were retested at the same time and had a mean value 5% below control maximal oxygen uptake.