Abstract
Cancer is a multifactorial disease resulting from the combination of the host (genetics, age, sex), environmental (viruses, radiation), and lifestyle factors (nutrition, physical activity, alcohol, smoking). While it is still the leading cause of death in developing countries and is the second leading cause of death in developed countries, there has been significant progress in our understanding of cancer etiology, early detection, treatment, and prevention in the past few decades. Physical activity, one of the modified lifestyle risk factors, is the lifestyle intervention opportunities of concern as nearly a quarter of the global adult population performs less than recommended physical activity. The World Cancer Research Fund in 2018 concluded that physical activity is strongly associated with a reduced risk of colorectal and breast, which are two cancer types with high mortality rates globally. Here we will explain various plausible biological mechanisms that link physical activity to the reduction of cancer risks categorized as an alteration in endocrine, immune function, metabolic, and oxidative stress levels, resulting in direct inhibition of receptors binding and reduce inflammatory conditions that support the development of cancer cells.

Key words: cancer, physical activity, prevention