Just 10 minutes of vigorous exercise can halt cancer cell growth. When colon cancer cells from obese/overweight adults were exposed to post-exercise serum and given a small dose of radiation, the cells had fewer markers of DNA damage and an overall faster DNA-repair response. The serum also raised PNKP, a gene that helps fix DNA. Looking at gene activity, the cancer cells increased mitochondrial energy pathways and dialed down cell-cycle and proteasome pathways, basically shifting toward energy use and away from rapid division. The post-exercise blood also had higher levels of 13 proteins (including IL-6 and its receptor), indicating systemic activation of immune and vascular signaling pathways. This helps paint a clearer mechanistic picture of why exercise seems particularly effective at reducing colon cancer risk.