Decreased physical activity (due to cancer or cancer treatment) can potentially lead to fatigue and low energy. Being forced to lie in bed or sit in a chair for long periods of time can produce feelings of anxiety, depression, weakness, fatigue and nausea, and regular moderate exercise can often reduce these feelings and help you stay active and increase your energy. Exercise can often be continued even during cancer treatment. But be sure to note: Consult your doctor before starting moderate exercise. A good exercise routine will start slowly, giving your body time to adjust. Maintain a regular exercise program, exercising at least three times a week. The right exercise routine will never leave you sore, stiff or tired. If you are sore, stiff, tired or have difficulty breathing due to exercise, you are overworking. Most exercise is safe as long as you exercise carefully and don’t overdo it. The safest and most productive activities are swimming, yoga, tai chi, brisk walking and low-impact aerobic exercise. If done correctly, these activities have a low risk of injury and are beneficial to your entire body. You should talk to your doctor if you are experiencing cancer-related fatigue. Sometimes fatigue can be a clue to an underlying medical problem, and some times there may be treatments to help control the cause of these fatigues. It is important to be aware if you have: shortness of breath or shortness of breath with the slightest activity uncontrollable pain uncontrollable side effects from treatment (such as nausea, vomiting, diarrhea or loss of appetite) uncontrollable anxiety or nervousness