^ PHYSICAL EXERCISE. 177 



the heart is w increased, the breathing is deeper and more 

 rapid, and there is greater activity of the circulation. Pure 3 

 fresh air improves the quality of the blood thus sent more 

 rapidly coursing through the system. The tissues of the 

 body are supplied with better material for building it up. 

 The waste products are given off more freely, and the skin, 

 kidneys and lungs have to do more work in getting rid of 

 these used-up particles. 



A daily walk of four or five miles, or its equivalent in any 

 out-door exercise, not only strengthens the voluntary muscles, 

 invigorating the whole system, but it also stimulates the 

 muscles which control the organs of digestion, improves the 

 appetite, and supplies the body with new material and new 

 resources. 



4. Time for Exercise. As a general rule, exercise 

 should not be taken whfre fasting, ncr very soon after taking 

 a meal. Experience has shown that in the one case prostra- 

 tion often follows, with loss of appetite, and in the other 

 digestion of the food is delayed, and sometimes stopped for a 

 time. While the stomach is most actively engaged, say, for 

 two hours after a meal, the body should have its leisure time. 

 Let the occupation be as light and the exercise as gentle as 

 possible for at least the first hour after taking food. 



Our longest period of fasting is during sleep. On first 

 rising in the morning the system is relaxed, and the body is 

 the weakest. This is plainly not the time for exercise which 

 is at all violent or prolonged. Some food, if only a morsel, 

 should be taken before going out to work or to study before 

 breakfast. The evening is not so good a time for exercise as 

 the earlier parts of the day. After the many hours of work 

 the energies are nearly spent, and the body is tired. 



It is just as important to regulate the form and amount of 

 exercise to the time of life as to the time of day. The little 

 child is not likely to take too much exercise. It will dro^> to 



