Bene fits and rationale for exercise during cancer therapy

In comparison with other areas of clinical medicine, exercise therapy has received comparably less attention in persons following a diagnosis of cancer. The precise reasons for this are unknown but likely stem from the prevailing dogma that a cancer diagnosis is associated with poor survival, a compromised immune system, that may be more compromised by exercise training, and other debilitating sideeffects that preclude participation in and benefit from exercise training as reported by Jones and Peppercorn (Lancet Oncol 11(5):408-410, 2010). Nevertheless, the past two decades have witnessed a dramatic change in attitude with a significant increase in research and clinical interest in the role of exercise therapy following a cancer diagnosis as reported by Jones and Peppercorn (Lancet Oncol 11(5):408-410, 2010). The increased interest in exercise has occurred in conjunction with the emergence of cancer survivorship and the growing importance of managing the lateeffects of cancer therapy in persons who are now living much longer following a cancer diagnosis. In response, investigators have examined whether exercise training is an effective therapy to recover/reverse the late effects of cancer therapy in patients following the completion of primary therapy. To date, approximately 40 studies have examined the role of exercise in this setting. Systematic reviews and meta-analyses of the extant literature supports the conclusion that structured exercise training is safe (few adverse events), well-tolerated (adherence rates >80%), and associated with 10-15% improvement in different measures of cardiorespiratory fitness in studies adopting traditional exercise prescription guidelines (3-5 day/week at 50-75% of baseline VO _2peak for 12-15 weeks). Patient-reported outcomes including fatigue and quality of life also improve as a result of exercise training following the completion of adjuvant therapy as reported by Jones et al. (Curr Treat Options Oncol 11(3-4):73-86, 2010); Speck et al. (J Cancer Surviv 4(2):87-100, 2010); Jones and Demark-Wahnefried (Lancet Oncol 7(12):1017-1026, 2006). Based on this evidence, the American College of Sports Medicine (ACSM) published the first exercise guidelines in oncology, recommending that all patients participate in regular exercise (i.e., ≥150 min/week of moderate to vigorous intensity exercise) after the completion of primary adjuvant therapy as reported by Schmitz et al. (Med Sci Sports Exerc 42(7):1409-1426, 2010).