Whenever you can make the time. Many men find it most convenient to exercise in the late afternoon after work. Exercise followed by a refreshing shower is much better than the tensions of fighting rush hour traffic. You can arrive home more relaxed and with a hearty appetite. Others find that a physical workout at noon feel more alert makes them  and allows them to work  more efficiently the rest of the day. They also find that they eat lighter lunches which is doubly good for weight control. The only time that we suggest you do not exercise vigorously is immediately following meals.