IamBaytor,
What condition are your knees in right now? You are fairly young, if your knees are in good shape, go for it. I was an avid jogger on mainly asphalt streets for 25 years with 8 years high impact aerobics in addition to that. Not too bright and not too good for knees.
Taekwondo is mostly jumping. The aim is to jump, get you to jump. I really love the jumping, but I pay dearly for it now. It can be done on the floor but the belts would not be passed, least not in most schools. A yellow belt taking the orange test has to do a hopping side kick/1 bd. So, the hopping, jumping starts practically right away to get the conditioning in. It is very cardiovascular in our school. It is also difficult to condition breathing with doing continuous jumping kicks down the line, length of the dojang, but it gets you in great shape. Doing that kind of a workout, gives me stamina and endurance. It is alot harder than running since it is partly anerobic.
Best dojang floor: A puzzle mat floor or similar is needed for knees. Not as good: wood floors, hopefully with carpeting which has some give. Terrible: cement with thin carpeting. We have puzzle mat on top of thick carpet on a wood floor, probably the best but really hard to balance on for form.
Glucosamine Sulfate taken religiously for cartilage renewal in the knee and less pain because it is helping the problem, not masking it like ibuprofen. My orthopedist recommended it to me but I had already been on it for six years and that is why I have stayed in TKD. Be good to your knees, repair as you go. Read up about it, it is I believe, safe to take and a natural element. Some though that are allergic to shellfish cannot take Glucosamine Sulfate but can take Glucosamine Chondroitin instead.
If you have any ligament problems wear a neoprene brace or knee strap-I wear one on my better knee like a V strap also called a jumpers strap, better safe than sorry. I tore cartilage trying to put my left knee back into joint after it came out doing a tornado round kick toward the end of an exhausting many repetition class (as a blue belt) I have weak ligaments due to sitting wrong on the floor as a youth.
Build up on repetitions slowly. The quadriceps is the main muscle group worked on with jumping but the hamstrings back of the knee have to be 90% of the strength of the quads in Taekwondo otherwise the hamstrings will suffer. I am doing different exercises for that because I don't do enough in class. But others, younger, are having those problems too.
Snapping kicks are a part of Taekwondo. We snap front kicks, round, and spin heels in training. Those are basic kicks we do all the time. If I were you, read the TKD threads about all these kicks. But MichTKD does have point that it might be injurious to snap on a hard surface. We snap kick on focus paddles which have give but we don't snap on targets like standup bags.
I also agree with landing softly. I find that a common mistake of newbies doing form too, coming down so hard in trying to keep balance or power their way through. Building up muscles, balance and coordination helps this.
Pivoting unfortunately hurts me if it involves any twisting of my standing knee but it may just be me and old knees. Pivoting and kicking in the right line is crucial to doing technique correctly and is easier on the kicking leg.
I can only say, I wished I had started it in my twenties but all knees wear out whether it is from continuous running or continuous jumping. Just take care of them. TW
