Rabbi Mosche Ben Maimon (1135-1204 A.D.) the most respected physician and philosopher of his age was truly ahead of his time when he made this prophetic declaration.
If a person cares for himself the way he cares for his horse there would be no serious illnesses. You do not find anyone who gives his horse too much fodder. He measures out only as much as the horse can tolerate. While he himself eats to excess. He makes sure his animal get proper exercise to keep healthy. When it comes to himself he neglects exercise even though it is a fundamental principal to health maintenance and the prevention of most illnesses.
Plenty has been written in recent years of the epidemic of obesity that is occurring in the US and its relation to Americans overeating. But often times not enough emphasis is given to the importance of exercise.
After following 15,000 US military veterans and evaluating the benefits of exercising the researchers concluded it is important to emphasize that it takes relatively moderate levels of physical activity- like brisk walking to attain the associated health benefits. Certainly, one does not need to be a marathon runner.