This goes on about a month and a half back.
I was going to do some cardio, so I jogged to the rec center (my school's gym/indoor track/basketball courts, about 1/4 mile away), did some stretches, jogged around 100m, and then did an all out sprint. Apparently I should have warmed up longer, as I pulled or tore or hyperextended my left quad. Basically I just was running really hard, and after I was going almost full speed, my quad (as my knee was bent) came up really, really ****ing high (my buddy was behind me and was like, "holy ****, you definitely ****ed that up").
Well, I sort of walked around a little that day, did some contrast showers, and for the past month and a half I've been mixing in some real long distance training. I hit my legs with power cleans and sled stuff and such, and I've never felt any problem with my quad in the past month. Well, today I figured it was certainly fine for me to get back on the track. So, I jogged to the rec center, stretched, jogged 200m, did some accelerates, and then ran 400m, rested, and then started on my second one, and about 40m into it I re-pull(?) my left quad, though not nearly as bad as before. It probably just wasn't healed from the last time, but since it wasn't bad I just finished my workout and kind of dragged my quad along. I wasn't running exactly fast--my first 400 time was 1:10, so the next one was starting at about the same speed.
Any idea on exactly what I did/how to fix it? Thanks.