Exercise can be hard enough for healthy people, let alone those battling cancer.

Adults should engage in at least 2.5 hours of moderate physical activity a week and in muscle-strengthening workouts two days of the week, according to the Centers for Disease Control and Prevention.

Those recommendations are the same for cancer patients, but the way they go about exercising may be different, depending on the toll that the disease and treatment has taken on their bodies, said Josie Gardiner, a personal trainer who co-authored "The Breast Cancer Survivor's Fitness Plan" (McGraw Hill, 2006).

Chemotherapy and radiation treatments are cumulative — meaning the more treatments you have, the more fatigue you will feel, said Gardiner, who has worked with many cancer patients and survivors. She often tells her clients to rate their fatigue on a scale of 0 (no fatigue) to 4 (totally exhausted) before deciding whether to undergo strenuous physical exercise.

"You have to listen to your body," Gardiner told MyHealthNewsDaily. "If you're totally fatigued, then give yourself permission to take a day off. But if you feel like you're only slightly or moderately fatigued, anything you do is better than nothing."

And just like exercise for people without cancer, the four areas of fitness — aerobic exercise, strength training, balance and stretching — are important, she said.

MyHealthNewsDaily takes a look at those four areas to see how each pertains to cancer patients.

Aerobics

Aerobic exercise gets the heart rate up and includes exercises like walking, bicycling and running. By alternating cardiovascular exercise with strength exercises, a person can increase lean muscle mass, decrease fat and increase the body's metabolism, Gardiner said.

"It's one of the best things to maintain body weight, because you're burning calories," Gardiner said.

Being overweight is a risk factor for cancer, Gardiner said, and maintaining a healthy weight can reduce the risk of cancer developing or recurring.

Physical activity can reduce the risk of breast cancer, for example, by 20 to 80 percent, the risk of endometrial cancer by 20 to 40 percent and the risk of colon cancer by 30 to 40 percent, according to the National Cancer Institute.

Aerobic excercise also can help people feel better while going through cancer treatments, and being fit can improve one’s recovery after an operation, Gardiner said. However, a cancer patient may not have enough energy to do 30 minutes of moderate or vigorous exercise a day. If so, the patient could do 10 minutes of exercise three times a day to get the same effect, Gardiner said.

Walking exercises are generally safe right after a person has undergone cancer treatment, she said.

Strength

Strength training improves muscle tone and fights muscle loss that can occur with aging, Gardiner said. It can be done with dumbbells, barbells and weight machines.

But bone density and muscle for an average person are different from those of a cancer patient. Chemotherapy can cause women to lose as much bone density in a year as the average woman would lose in a decade, Gardiner said.

"That is a huge reason why strength training is so important: As muscles become more dense, then they're going to put more pressure on the bone," Gardiner said. "Trying to maintain bone density through strength training and weight-bearing exercises like walking will help you maintain bone density."

Weight training won't increase bone density, but it will at least help to maintain it, she said.

Cancer patients should consult their doctor before undergoing a weight training regimen, Gardiner said.

Balance

A good sense of balance is vital for a workout free of slips or tumbles, Gardiner said.

For some cancer patients, drugs can impair balance. And for those on chemotherapy with decreased bone mass, it takes only one fall to break a bone.

Therefore cancer patients and survivors should make sure balance exercises are a regular part of their fitness routine. Simple exercises such as walking a narrow path (putting one foot in front of the other, as if walking a tightrope) or heel raises (standing in place and raising each heel up and down) can improve balance, Gardiner said.

Some other balance exercises are single-leg stands, in which a person spends 60 seconds standing on one leg, and grapevines, which involve stepping sideways and putting one foot in front, and then in back, of the other, she said.

Balance exercises are generally safe to do even right after cancer treatment, Gardiner said.

Stretching

For some cancers that require surgery, people may feel particular weakness in certain parts of their bodies, Gardiner said. For example, breast cancer survivors who have undergone mastectomies may feel weakness where the rotator cuff may be, at their shoulder girdles, she said.

"There are exercises specifically to strengthen the shoulder," Gardiner said. Women who had breast cancer may want to do an exercise in which they face a wall and “walk” their arms up the wall to increase their range of motion.

"But they only want to go to the point of tightness, not pain," Gardiner said. "Doing these stretching exercises for the areas that they've had surgery" could help them regain mobility in those areas.

However, cancer patients should consult with their doctors before undergoing stretching exercises, Gardiner said.

Pass it on: Exercise is a necessity for cancer patients and survivors, but their condition poses some unique challenges.

it depends on the situation, for example lymphedema post breast surgery requires a special kind of exercise 

Generally speaking, regular exercise (walking) is universal for people regardless of whether they have cancer or not. If the cancer has been removed surgically, then the exercise is  for building up fitness (rehabilitation)  and as  a contribution (though limited) to prevent further disease. Perhaps, getting specific advice frpom the managing doctor/centre is more appropriate for this case 

Please take a look at this useful RG link.

Article Exercise for People with Cancer: A Clinical Practice Guideline