Yes, all the time! Keeping fit is a passion for me, and helps with everything -- not just hiking. Regular exercise keeps me injury-free, makes daily tasks as easy as they were when I was a kid, makes waking up painless, improves my digestion, my eyesight, my sex life ... I could go on and on and on.

I've done some sort of frequent regular exercise all my life. I've come to ferverently believe in both cardiovascular exercise and strength training.

Of all the exercise methods I've tried, one stands far above the others for injury prevention and general fitness: Russian kettlebells. The way these things are used builds core strength like nothing else I've tried, and through the use of largely ballistic, off-center movements, prepares my body for exactly the sort of momentary extreme trauma that causes injury. Kettlebell workouts tend to build strength without bulk (making them a favorite among women), increase flexibility of connective tissue, increase cardiovascular health and VO2 maximization.

Kettlebells do require good instruction to use safely and effectively. I don't recommend picking these things up without proper training.

One more thought: While regular exercise is wonderful, I'm not so sure about the idea of a "routine". I think the best way to prevent injury is to switch up exercises regularly. Routines tend to strengthen the body for a certain finite set of motions -- injuries happen when we suddenly find ourselves outside that comfortable range. So the more varied the exercise, the better prepared I feel for the unexpected lurch, fall, twist, etc.