Science-Based
Why is Exercise Rehabilitation Good for Cancer?
Due to the interrelatedness of cancer treatment side-effects, it has been postulated that a drop in physical strength and cardiovascular ability may be major contributors to cancer fatigue and most if not all of the typical side-effects of the medical treatment process.
A bio-behavioural model - that summarises the evidence for the biological, psycho-behavioural and functional mechanisms that contribute to cancer-related fatigue - explains how virtually all cancer treatment symptoms may be altered by physical exercise. Scientific evidence reveal that cancer and its treatment may increase the risk of other common conditions such as cardiovascular disease, diabetes, and osteoporosis. Numerous studies have provided conclusive evidence that cancer patients under treatment who exercise exhibit a decreased risk of developing cardiovascular disease, diabetes, and osteoporosis. For a lot of newly diagnosed patients, the oxygen demands of surgical stress (recovering from surgery) outweigh their baseline functional capacity. Patients that are in essence not physically strong and fit enough to survive the treatment process. Scientifically designed supervised prehab (e.g., exercise training before medical treatment starts), maintenance rehab (e.g., exercise training during chemotherapy) and restorative rehab (e.g., exercise treatment after surgery) are non-negotiable especially for borderline patients (e.g., patients just above or below the cardiovascular fitness cut-off).
Table A: Effect of cardiovascular fitness on post-surgical recovery
Illustrated above is data of a study by Osler et al. (1993).
Table 1 (table on the left inside Table A) show that low level cardiovascular fitness (< 11 ml.kg.min-1) resulted in an 18% higher mortality rate.
Table 2 indicates that cardiovascular fitness level is even more important in those with co-morbidities. Those with angina ─ and anaerobic threshold of lower than 11 ml.kg.min-1 ─ exhibited a 42% higher post-surgery mortality rate.
The challenge cancer patients face is that unless they are provided with a structured and supervised exercise program most individuals are unlikely to engage in physical activity before, during and after treatment.
The schematic illustration below outlines the value and importance of guided physical exercise rehabilitation during the various stages of medical treatment and during the post-treatment recovery stage.
Table B: Schematic illustration of impact of exercise rehabilitation during the various stages of cancer treatment
As can be seen in the illustration (above), patients who receive both pre-and post-exercise rehabilitation can restore pre-medical intervention functional well-being levels. Take a careful look at the illustration in Table B. The three main observations from this illustration are:
1. The sooner cancer patients start with exercise rehabilitation the better the recovery results
2. You can’t store the pre-treatment exercise benefits. It is important to continue with exercise rehabilitation after completion of the medical treatment (e.g., surgery, radiation and chemotherapy)
3. Late starters (e.g., those starting with exercise rehab after cessation of the medical treatment) still exhibit better long-term recovery than individuals who never start or who discontinue their exercise rehabilitation.