Running in your 20s will improve your memory in later life.

Apart from reducing your risk of heart attack, high cholesterol, high blood pressure and diabetes,
being really great for your heart, and increasing your lung capacity; it may also have an effect on how much you can remember in your middle age. Participants, all aged 25-years-old, were given a test while on a treadmill. They were studied while walking or running on the treadmill until they were out of breath and had to stop. Their average running time was 10-minutes. Twenty years later, that number fell to three minutes. Participants were then given cognitive tests that analysed their verbal memory, executive function, and their brain’s relationship between thinking skills and physical movement. For every extra minute people completed on the first treadmill test, participants got 0.12 more words right in a word memory test. Although the differences were modest, the researchers note that the memory-related tests used in the study have been shown to be accurate identifiers for dementia. So "never too late" definitely does not apply to this situation.