I haven't had a injury but one time when I weighed about 181 lbs I ran 3 miles non stop and after I got off the treadmill I could hear a clicking sound in my knee, it did'nt hurt or anything but it kinda let me know that I pushed my body way to far
I'm 53, guess I'm the ole fart here I've had two injuries in 25+ years of exercising... The first one was trying to run too far too quickly and got sore knees, and that resolved itself by slowing down, not increasing my mileage so quickly and Glucosamine... I no longer take Glucosamine and my knees are fine... The second was my shoulder which was an injury than came sloooowly over time and I ended up having to see a physical therapist, it still bothers me if I'm not careful when lifting, but it's ok for the most part...
Oh, and another injury happened about 10 years ago while rollerblading. I fell and pulled a muscle in my calf and ankle, I never got it checked, but maybe I should have it was black and blue... I used ice and heat for a few days kept it elevated and did no workouts for about 4 weeks... Today it's fine...
I wasn't exercising, but I injured my back due to improper lifting. I didn't use proper technique because I wasn't lifting any heavy weights or anything. Nope, I was just lifting my heavy body! My back muscle strained under my own weight. It was super embarassing. I felt like an old person in a sit com (you ever notice how old people hurt their backs everytime they bend over in sitcoms?) Anyhow, my instinct was to rest it (I didn't go to the doctor). So I stopped working out, and the pain would not go away. Then my mom told me I should try doing some exercises, low and behold it healed up nice and quickly!
I hurt my back pretty badly when I tried to start the C25K program early this year. I had decided I wanted to run, so I went and got fitted for running shoes at my local running store. I ran maybe three times (not on consecutive days) and then one morning, I just couldn't stand up. I could walk - with great pain - but I couldn't straighten my back. I thought I had slept wrong.. or run poorly. I had to visit family that day and I didn't want to NOT go (since we don't get together often anymore). On the way up the stairs, my husband actually had to stand behind me to prevent me from falling off because it hurt so badly to lift my feet that high. When I woke up the following morning in WORSE pain, I went to urgent care. They couldn't explain it for me and sent me home with muscle relaxers and inflammation reducers. Another two doctor visits, x-rays, and and MRI later it was confirmed that I have two slipped disks and one that's compressed. Doctor said it looked to be from old injuries, but I've never been in a car accident... or any accident for that matter. Anyhow. I had to rest for four months - no walking or anything for exercise. After that, I still couldn't run if my life depended on it. Now here I am more than 10 months later and a runner. It ends up that it was the shoes, I was improperly fitted. When I returned the shoes and gave the explanation, they took them back. I returned to the store and was fitted by a different man and this time they were much better. Not to mention I told him my story and he was extra careful... It's interesting how we take our ability to walk for granted every day. I am very aware of my legs and back now.
I don't think I could have avoided it... I didn't know any better. BUT you can guarantee I will never make that mistake again!
I've had various sport and exercise related problems and injury. I've learned lessons...but not sure what they are...
Last year, I was fed up with my sore knees. I'd seen my PCP and orthopedist but they had no solution. They thought it was minor arthritis. I told them I was exercising to lose weight. On my own initiative, I decided that I needed to stop all biking and exercise. I also completely commited to lose all my excess weight--no holds barred (I targeted 35 pounds to lose). I lost the weight this year and my knees slowly resolved themselves. I thought, "well there you go. Problem solved".
This August, I went home for a visit after losing 37 pounds. While on vacation, I decided to go for a run. At home, I normally exercised on wood floors with home dvds for 60-90 minutes (4-5 times/week). Well, I ran out for 45 minutes, turned around and ran back for 45 minutes. I did the same thing the next day. A couple days later, I asked my tri-athelete cousin about his running routine. He looked at me shocked and said that it was too much running on concrete and you're not supposed to run two days in a row. Opps. Oh, well, good to know...
About two weeks later, I had increasing hip pain and my orthopedics doctor couldn't see me fast enough. I was in the ER with excruciating pain that built by the minute. Neither my orthopedist nor the ER doctor diagnosed me correctly. My friend who's a pediatrician told me I had classic signs for a pinched nerve. After much trouble with doctors, I did finally get diagnosed with an L5 nerve pinch (similar to sciatica). I'm on meds and working it all out.
Another issue is that my sore knees are back. I thought it was only weight related--which I'd solved (thank you very much). I looked it up on-line and now realize I have classic "jumper's knees". It's a common issue for volleyball, jumpropers, or soccer players.
I wish my orthopedics doctor had taken me seriously when I said I exercise ALOT. I feel like she didn't think I could possibly have a sport injury because I'm a 42 year old mom. She had also misread my hip problem which turned out to be a progressing issue with a pinched nerve.
My learning lessons: hmmm, that's tough. I lost a lot of weight thinking I would solve my sore knees. The weight and the knees seem to be unrelated. But because of my mistake, I lost a lot of weight and feel awesome.
I have been diligent to go to my doctor and PT staff. However, I'm the one who properly diagnosed two serious pain problems that were leaving me with so many months and months of pain.
So, I would say that the speaker at the conference I went for my office was right...you don't have to live in pain. Keep working at finding the solution, check many sources if the problem is not resolving, losing weight will almost never make a problem worse (and may solve it), core body conditioning is important to resolving and preventing problems, stretching yoga is very good for you, and finally you can often find ways to do the exercise you want if you really educate yourself thoroughly.
When I first started walking/jogging I noticed my upper thigh getting numb. This past week the Dr. told me I have nerve damage in that area or hip area. First accuired from a car wreck and then aggravated by the exercise.
I've had two injuries in 25+ years of exercising... The first one was trying to run too far too quickly and got sore knees, and that resolved itself by slowing down, not increasing my mileage so quickly and Glucosamine... I no longer take Glucosamine and my knees are fine... The second was my shoulder which was an injury than came sloooowly over time and I ended up having to see a physical therapist, it still bothers me if I'm not careful when lifting, but it's ok for the most part... 
