Worldwide published evidence clearly demonstrates that regular exercise helps well-being and cancer in four main ways:-
Exercise prevents cancer
In terms of prevention, its has been estimated that being sedentary and overweight could account for 14% of male and 20% of female cancer deaths in the UK. For bowel cancer, for example, most environmental studies have demonstrated a reduction in the order of 40–50% for those at the highest levels of physical activity, with many demonstrating a dose-response relationship. The Harvard Centre for Cancer Control, for example, estimates that at least 15% of colon cancers could have been prevented by 30 minutes daily exercise a week. These data suggest that increasing physical activity is one of the major factors that is amenable to modification by individuals wishing to reduce their risks of cancer.
Exercise helps to fight established cancer.
Regular exercise after a diagnosis of cancer has been shown; to slow the growth rate of some cancers such as prostate or low grade leukemia’s; reduces the risk of cancer coming back and improves cure rates.
Exercise after cancer reduces relapse rates and improves survival.
Several large international studies have clearly shown that individuals who exercise regularly after cancer have better outcome sin terms of relapse rates and overall survival. For breast and bowel cancer between 2.5 – 3 hours a week of vigorous exercise appeared to to be the target level, for prostate cancer the target was 3- 5 hours
Exercise has been proven to helps side effects and risks during and after cancer treatments.
Regular exercise increases the sense of self-empowerment for both the patients and carers who can also join in with the activities. It improves social integration and can make you feel good about yourself. Many patients reported that exercise restored their confidence earlier after cancer treatments finished. As well as these general measured, the is strong evidence that exercise has major benefits on many of the symptoms and side effects experienced during and after cancer treatments
Underlying mechanisms of how exercise fights cancer
A number of important physiological changes occur in the body during and after exercise which have specific anticancer properties. As well as helping reduce weight which in the long term has anti-cancer benefits these include:
- Prostaglandin levels
- Decrease in Insulin like Growth factor
- Reduction in unhealthy blood fat levels
- Increased bowel transit time
- By improving body condition and weight
Specific exercise advice
After specific treatments such as surgery and radiotherapy, as well as generally getting fitter, it is advisable to perform the specific stretches and exercise advised by the nurses/physiotherapist or doctors. You should have been given a specific sheet to follow in these situations. If you feel you unexpected problems on or after treatment or have any worries or barriers to exercise you can asked to be referred to a physiotherapist.
Worries and concerns
Exercise is generally save of course people can fall off tread mills or sprain an ankle running but the benefits completely outweigh the risks. Nevertheless there are some special precautions which should be taken after cancer. If concerned in the first instance, the best way to get started is to ask your doctor or GP to refer to an exercise professional who has qualification in cancer rehabilitation (level 4) on the national exercise referral scheme. This will ensure you are supervised by a a professional who is sympathetic and aware of the limitations and symptoms which are common after cancer; know what to look out for and know what to do if a problem were to arise during exercise.
About exercise during chemotherapy;
Vigorous exercise will be difficult during chemotherapy and may actually increase the level of fatigue. However regular light exercise and avoiding periods of inactivity will improve fatigue digestion and reduce the risk of thrombosis (blood clots). In September 2010, various newspapers reported the results of a laboratory trial from Ohio and some made the inappropriate conclusion that exercise before chemotherapy is ill-advised. They based this around issues with a chemical called Heat Stock Proteins (HSP) which are activated by the body in response to cellular stress such as attack from chemicals, high temperature, infection or lack of oxygen (hypoxia). More specifically the heat shock protein-1 activates another protein called Hsp-27 that helps to block cell death. It also interacts with a third protein, p21, which allows cells to repair themselves and keep dividing. Much of the research up to now has concentrated on how this mechanism protects normal issues such as the heart in times of hypoxic stress. The main stimulus for the body to produce HSP is a raised temperature (associated with infection), lack of oxygen (such as a heart attack), steroid injections such as dexamethasone (routinely given with chemotherapy) and indeed chemical attack from chemotherapy.
Researches recently have found that people who exercise regularly tend to have higher baseline HSP levels, and is one of the explanations why they tend to look younger and this protein encourages cellular repair. This seems all good up to now however experiments involving breast cancer cells from Ohio, showed that adding HSP to the cancer cells in the petri dish made them more resistant to chemotherapy because it was also encouraging the cancer cell to repair – which we do not want. Following this there was a media frenzy warning that exercise could diminish the killing effect of chemotherapy. They made no comment on the fact that, if indeed HSP were increased in the body, it also would also diminish the harmful side effect, including heart damage. And, although this has not been proven, I suspect the benefit in terms tissue protection would out way the tumour sparing effect – thus actually increasing the therapeutic ratio of chemotherapy. Certainly a therapeutic procedure called hypothermia (used with chemotherapy and radiotherapy) suggests that heating the tissue actually kills more cancer cells without killing the normal cells.
In summary There is no evidence, at all, that in humans exercise diminishes the chemotherapy effect. There are several benefits of exercising during chemotherapy. In view of the new Ohio experimental data more research is necessary to see if exercise may actually be a way to further increase the therapeutic ratio. We advise regular exercise during chemotherapy and afterwards – consider joining a gym or/and a personal trainer. However, although the evidence is poor for any risk, we advise avoiding extreme aerobic exercise (sprinting) 48 hours before chemotherapy especially in very hot climates/ rooms especially if you do not exercise regularly.