Scientists have found that just 10 minutes of intense exercise can change the composition of the blood so that it increases the level of small molecules with an anti-cancer effect.[6] These molecules activate DNA repair mechanisms in cells and at the same time can stop signals that promote cancer growth.[6] When the researchers applied these molecules from post-exercise blood to colon cancer cells in the laboratory, they observed changes in the activity of hundreds of cancer-related genes.[6] The observed changes in gene activity suggest that short, intense exercise can directly affect the behavior of cancer cells.[6] The results provide an explanation for why physical activity reduces the risk of cancer and can influence its course.[6] Research shows that the effect appears after a single short training session, without the need for a long-term exercise program.[6]