Taekwondo can be practiced by just about anyone in any sort of physical condition. When some people think of Taekwondo they think of doing fancy combo 540 kicks 10 feet in the air. But if this all Taekwondo were about, how would 80 year-olds still be practicing and enjoying the sport? I believe training for Taekwondo is about balance and as I've said before, consistency. Maybe when you are a teenager those fancy kicks come easy but as you become older; flexibility becomes more difficult to maintain and as you start to feel a little slower, these kicks become a thing of the past. That's ok, you still have plenty you can do.

Get back to the basics of training for Taekwondo: front kick, round house, side kick, back kick. You are more likely to use some form of these in a real fight anyways. The fancy kicks will usually just get you knocked down as you are spinning through the air.

Practice your forms. I'm sure it's happened but I haven't heard of a lot of injuries from forms. These mostly consist of basic kicks, stances and get you back to the good fundamentals. In the end the goal is to not get injured so you can keep practicing and keep making gains.

As I've said before, you don't need to take every workout to the wall. In fact, pushing yourself to the point of exhaustion while sparring will greatly increase your chance of injury. Even if you aren't practicing punches and kicks you can always train for Taekwondo simply by interval training. Jump rope, hit the heavy bag, use the elliptical (a nice low impact exercise for the knees). When we spar we are interval training by performing quick bursts of motion followed by periods of rest. Any kind of interval training will help our endurance in a fight.

Whatever you do, make sure you keep stretching. Young or old do not stop. This is a fundamental piece of training for Taekwondo. I believe this is the number one thing you can do to keep yourself feeling young and to keep your risk of injury to a minimum.

The main point I'm trying to make here is just to keep going. Don't worry about what you used to be able to do. Don't compare yourself to anybody else. Just keep practicing good technique, keep stretching, keep kicking and punching and keep getting your heart rate up. Listen to yourself and avoid injury. If you do this consistently you will have no choice but to improve in one form or another and you will be able to continue training for Taekwondo for life.