I started exercising after a long time and did some exercises of legs (running, squatting, etc). The exercise was not strenous. Just after the session I had to go to a party, so I jumped in my car and drove to the location which was an hour away. When I tried to get out of the car and stand up, I couldn't. I didn't feel any strength in my thighs. I summoned all my strength and got out of the car and collapsed back on the ground. Few people helped me get in a room and I lay there overnight. After spending the night wondering whether I had lost my legs, in the morning I was able to stand back.
Now why did this happen? What can I do prevent it from happening again?