REVIEW Pre-clinical investigations of physical activity and cancer: a brief review and analysis

There is substantial evidence that physical inactivity is an important risk factor for a number of chronic diseases, including cancer. As consequences of physical inactivity on cancer risk and treatment efficacy surface, there is increasing interest in determining the benefits of a phy-sically active lifestyle and of exercise as a component of that lifestyle. In the cancer research field, the spectrum of research activities includes pre-clinical studies and clinical and population-based interventions; of these approaches, pre-clinical experiments combining animal cancer models with physical activity (PA) have been underutilized. Clarifying the amounts and types of PA that inhibit carcinogenesis is best done in animals, where mechanistic inquiry and biomarker evaluation of the protected state can be carried out in a more favorable environment than in clinical populations. The expertise required to integrate models for investigating PA with those used to study carcinogenesis is not trivial, but mastery of these models is likely to result in highly translatable pre-clinical findings that advance this important field of investigation. This brief review and analysis is intended to focus attention on the issues and opportunities associated with the pre-clinical investigations of PA and cancer