Exercise is a tonic that tunes up the body. It strengthens organs,
refreshes
blood, relaxes nerves, and sharpens senses. But exercise must also be
safe.
So I recommend non-competitive, non-contact, low-impact, aerobic exercise,

such as walking, stair-climbing, and swimming. Contact sports (football,
soccer), impact sports (running, tennis), and anaerobic sports (weight-
lifting)
emphasize competition and often lead to injuries. All exercise programs
require medical supervision, proper diet, comfortable clothing, warm-up,
reasonable levels of exertion, fluid replacement, proper timing (no food
an
hour and a half before and after exercise), and adequate rest periods. The

rest period is important, because it allows the body to recover from
exercise.
The length of the rest period depends on the type and degree of exercise.
For
example, short walks can be done every day, but long walks should be done
every second or third day. Vigorous exercise, such as stair-climbing, may
require even longer rest periods. Regardless of what kind of exercise you
choose, don't overdo it. A safe, regular exercise program enhances your
health, work, and relationships.

Competing interests:
None declared