Exercise is now generally believed to be neuro-protective. There have been extensive confirming studies on this, though the exact types, levels and amounts of exercise that are optimal is not yet known.
But here are some of the resources that have shaped my approach:
As this study reports succinctly: “Exercise builds brain health”, and then it goes on to explore how.
How much exercise is optimum remains a big question. This Harvard piece suggests an hour a day may be optimum, but half that amount also confers great benefits.
I have come to believe that the optimum amount of exercise may be about an hour a day, with about 1/3 of that time being strenuous, including a mixture of things like high-intensity interval training combined with some weight training.
It seems that BDNF (Brain Derived Neurotrophic Factor) may be one of the key connections between exercise and brain health, and this piece gets into more details on how:
Exercise-Mediated Neurogenesis in the Hippocampus via BDNF
This connection between exercise and nerve growth (also know as neurogenesis) is further explored here:
Exercise and new nerve cell growth in Alzheimer’s disease
The connections between exercise and the brain across BDNF are also explored in this great overview piece from Elemental.
The need for some of our exercise to be strenuous, or at least aerobic, is further explored here:
Aerobic Exercise Tied to Better Cognition at All Ages
Beyond that, just generally moving around is good—for me that is doing lots of walking and hiking, but as always, you need to find a personalized approach that works for you—"your mileage may vary”!
Exercise helps prevent, fight Parkinson's disease, from the Harvard Health Letter
Disclaimer: I offer all of these suggestions not as a Doctor or Researcher, but as a Patient, and a “Citizen Scientist”. None of this should be taken as medical advice, and certainly you should consult your Doctor when it comes to making decisions about your health.