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The protective role of physical activity (PA) has been demonstrated in numerous diseases, especially cardiovascular and metabolic ones, but also in various neoplastic pathologies.

It has been estimated that approximately 25% of cancer cases globally are due to excess weight and a sedentary lifestyle. Regular moderate-intensity or greater physical activity is associated with a reduced risk of several types of cancer. Most studies have shown this association especially for breast, colon, and endometrial cancer.

The mechanisms through which PA may decrease cancer risk are numerous: physical activity might work through reducing the amount of adipose tissue, thereby lowering circulating levels of estrogens and other sex hormones, PA improves insulin resistance, reduces hyperinsulinaemia, might reduce inflammatory markers, thereby decreasing the exposure to these potentially carcinogenic hormones and peptides, reduces oxidative stress, reduces gastrointestinal transit time and improves immune system by increasing the phagocytic activity of macrophages and neutrophils, and increasing the proliferation of natural killer cells and lymphocytes. Other mechanisms under investigation pertain angiogenesis, DNA repair, and growth factors.

In addition to hormone-sensitive tumors and colon cancer, new evidence suggests that similar associations with PA might exist for other cancers for which less is known about the potential mechanisms underlying the physical activity association, suggesting that further mechanistic research is warranted.

Furthermore, in people who have already been diagnosed with cancer and are undergoing oncological therapy, regular exercise helps to counteract some typical and common side effects of anti-cancer therapies, thus improving treatment compliance and the overall quality of life. In particular, physical activity seems to reduce fatigue, arthralgia, nausea, improves cardiovascular and respiratory capacity, reduces the risk of osteoporosis, and anxiety.