I get asked quite frequently by my injured, overweight or elder patients "What kind of exercise can I do to build up strength without hurting myself?" As I've grown older myself, I've had to modify my own exercise routine (which used to consist of weight training 2-3 times per week), and I think you are going to be thrilled with what I've discovered:
Isometrics! Now before you tune me out and write this off as "too simplistic", please hear me out. This 5 minute work out is not intended to bulk you up, but merely strengthen and tone your muscles. Yes, it will build a little muscle, and if you do longer sessions, isolating each muscle group, you can actually add muscle mass!
One of my colleagues used isometrics to put on 10 pounds of muscle mass in only 8 - 10 weeks. But he was doing about 15 minutes per day (the animal!), but he broke it up throughout the day to focus on different muscle groups. You can do these almost anywhere, whether it's at home, at work, the bathroom...anywhere you can take a 5 minute break.
How I do it: I stand in front of a mirror so I can see which muscles I'm trying to isolate (which is ALL of them), and starting out at about 75% maximum, I gradually build up to 100% contraction. I hold my arms out to the side, contracting the chest, abs, lats and back muscles, as well as my thigh and glut muscles. I squeeze as hard as I can for 30 seconds, and take a 30 second break in between while I brush each quadrant of my teeth while I'm getting ready for work. This allows me to do 5 sets of contractions, and by the time I'm done, I'm breathing hard and fully awake for the day.
When I'm fully contracting, my body shakes, but I don't hurt anywhere while I'm doing it. You WILL feel muscle soreness the next day, however, if you're doing them correctly. But since giving up weight training, I haven't injured myself anymore, my muscles are tone, and with proper diet and a simple walking program, it's easy to shed pounds and easily maintain a healthy weight.
You can focus on you thigh and ab muscles even sitting down...or while you're sitting in traffic. If you want to get really aggressive, you can push against walls, hold a squatting position, or isolate any muscle you want to tone up. Just be careful when you're pushing against immovable objects, because you can overdo it and hurt yourself. When you just resist against you own body's antagonistic muscles to balance the contraction, it's very difficult to hurt yourself.
Try it! What do you have to lose, other than a few inches, a sagging body and poor self-esteem? And who can't fit in just 5 minutes a day? NO MORE EXCUSES!!!