Meaningless dribble.
Even if this analysis were correct (and as a weak statistical association, it probably is not), it would only be meaningful on a population-level. Individuals have their own risk factors, which may or may not be modified by exercise. And since no one truly knows what the nature of her risk is, the result is of no value in the best case.
Data show that the one factor that most reduces the risk of breast cancer (and ovarian cancer) is the presence of a Y chromosome. Unfortunately that carries the side effect of a greatly enhanced risk of prostate cancer and testicular cancer.
Datadredge studies from China are notoriously poorly conducted. It lumped together data from 31 studies from all over the world with differing methodologies, data, diagnostic abilities, populations and controls into a meta-analysis; then found relative risks that failed to be beyond random chance, statistical error and confounding factors. It’s part of a growing movement to demonize western lifestyles and promote “healthy” lifestyles (as defined by more junk science) and cruelly blame chronic diseases of aging on the victims.
Where they’re going with this: Governments are increasingly trying to convince us that it’s their own fault if someone gets a chronic disease, therefore they don’t deserve money for medical care.
So cancer is caused by becoming a couch potato? Anyone know of the causal mechanism in there?