I hate to say it, but it could be your new shoes. I've had the same thing happen. i went to a running store I trusted and had a pro fit me. They felt fine in the store, but the first time I ran with them I felt a twinge in my "weak" knee. I ignored it until about a month later when it suddenly turned into horrible pain that shot from my knee down to my ankle and didn't go away after I stopped running.

I found a new pair of shoes on my own after lots of trying out in the store. I used them for a month, still liked them, and went back and bought 3 pair to keep for when the first pair wore out.

I hope your knee gets better!

I have a problem in my right knee when I do a lot of high impact cardio and other activities. I'd recommend seeing a doctor -- it could be a lot of things, and you might be hurting yourself. The doc may be able to recommend good solutions for what ails you.

What the others said, plus strength training for your quads and hammies. Depending on the general shape you're in that might be leg lifts in your living room, wall squats or full-on squats. If you build up the muscles around your knees then there is less pressure on your knees.

Were you running ok before you got the new shoes?

Yes, the reason I suggested a doctor is that after he looked at what was wrong with my knees, I was told NOT to do anything for quads -- which were too strong compared to my hammies. So for now, no squats and lunges for me, but lots of prone leg curls. A doctor (orthopedist) should be able to tell the specifics of what is wrong with you, personally, which may be different than what is wrong with someone else.

I've had knee troubles for years. I have arthritis in my knees from being overweight for so many years, as well as my right knee being somewhat out of place. When I first tried running, I had problems with my knees. I regularly wore support on my right knee as it would hurt in general through the day, especially if I took the stairs. So I tried running with that. However, the running also caused my left knee some minor trouble. And like you said, the Wal*Mart support was bulky. So I went back to Wal*Mart and got those elasticized slip on supports. They're about 5 inches from top to bottom and you simply put them over your foot and pull them up your leg over your knee. There's no wrapping them around, they're not stiff, they have no hole in the center. Its like wrapping your knee in an Ace bandage. One on each knee helped me to run. After losing the bulk of my weight, I eventually gave up those supports and don't have those knee troubles anymore.

As for shoes, if you do have problems with shoes, some stores will let you return them and try a different pair as long as you don't wear them outside. So keep them to the treadmill until you know for sure they're working for you.

I know you want to run. But you need to stop until you see a doctor.

The fact that the pain is on one side indicates some sort of injury to that side, or some physiological problem, that needs to be addressed. Aching on both knees could be arthritis or just your body not being used to what you are doing, but not generally on one side. Knee problems get worse if they aren't treated, and you need to see a doctor to find out what the problem is, what needs to be done to fix it, and how much activity you should do in the meantime.

Basic rule - if it hurts and feels like it is going to give out....STOP! If that knee actually gives, you're talking about going, for example, from a ligament STRAIN (which hurts and needs to be rested and treated) to a ligament TEAR (which could require surgery to repair). That is just one possibility for what could be going on.

I've had knee problems my whole life. Do not mess with them. I learned that after my first surgery :-)

...note to add, if you can't afford to see a doctor, you need to switch immediately to non-impact cardio...swimming, etc. And no more leg exercises that hurt!

I'm in the same boat as you but with my left hip. I started running and the pain was pretty bad. I talked with the shoe fitters at my running store who told me to see a doctor. So I went to my doctor and didn't get a whole lot of feedback. One of his concers was running "at my weight." This may be an issue for you as well. My advice (and what I did) was take some time off and do some strengthening exercises specifically for the knees and hips. Look in some running magazines or sites for runner's specific training, there's a ton of information out there about the causes and things to help. Here is an article that I tried that seemed to help for my hip. Oh, and make sure you start SLOWLY. I'm now running up to 6 miles and up to 10min/mi but I started out with 10 minutes at 4.0 on the treadmill. And by the way, I still deal with the hip, but the stretching and training has helped a ton!

I want to add on the doctor note. I knew I had problems with my knees, but frankly, the doctor would've told me not to run. However, using the supports took the strain off my knees and I had NO knee troubles when I wore them. I tried jogging without them a few times and always had knee pain from it. But as long as I wore them I had none. I'd say if you try the supports and get no pain, that the injuries you have are likely being stressed from the impact of the added weight AND the existing problems. Once my weight dropped, I no longer needed the support and don't have pain anymore. And I started at well over 200 pounds.

Going to the doctor IS sound advice, don't get me wrong. But I'd try it with the supports and see. If it doesn't bother you with them, they could be your solution.

Never exercise on a joint injury unti you know the extent of it. It could be nothing more than inflamation, in which case an anti-inflamatory and a brace should fix you right up. Or it could be something more serious. Seriously, if you keep going it may not be trouble running you have, it may be trouble walking!

I "ran through the pain" on a joint injury and am banned from all impact exercise for at least another year. That includes long walks!