I can understand you worrying about getting injured, but you can actually lessen the toll it takes on your body very easily, it just takes working at it. I am 53, not that young anymore but, I found 10 years ago, when the big C started to make me weak I needed to make my body stronger. So, I started to excercise more. Through so many health problems, which include the Big C and actually, heart problems due to the chemos, (3 heart attacks) I have managed to pull it all together and now, thankfully, I am pretty strong. I am not gloating here, just trying to set an example it can be done. You can turn it around, especially at your age. Buy an excercise bike & treadmill and put it in your garage. It really works. Then you will be able to whip those suckers up & over your head without a worry. I had a father who was the strongest man I ever knew. At age 61 he could lift a sofa up and over his head, by himself. His brother walked at least 10 miles a day. It is fun to change your lifestyle around andI like to challenge myself. I am going to run one year in the Boston Marathon and Heartbreak Hill is a big challenge ask any New Englander. Just do it Rugged for 6 months, see what happens. You have nothing to lose.