Association between muscular strength and mortality in men (2008) [pdf]
I've been doing strength training (the program is called Stronglifts 5x5[1]) with freeweights for about 9 months now.  I just turned 44, and I've never felt better, and I'm stronger now than I have ever been.  The program I use describes 3 simple exercises to do 3 times a week, and each workout takes me 30-45 minutes.  Very little equipment is needed.  It's hard to find good information about this on the net that covers both what exercises to do, how to do them, and how to eat.  This program covers all of that, taking you from lifting an empty bar right on up.  It's totally free, with an option to pay if you want personal consultation.<p>I used to have knee pain, and I don't anymore.  I used to get a sore back from coding all the time, and I don't any more.  I seriously recommend trying strength training.<p>[1] <a href="http://stronglifts.com/stronglifts-5x5-beginner-strength-training-program/" rel="nofollow">http://stronglifts.com/stronglifts-5x5-beginner-strength-tra...</a>