I'm a hurdler and sprinter and for the most part of the last outdoor season I practiced and competed in flats. A lot of people said they were bad for my knees and stuff, but I felt fine practicing in them. My question is is it okay to practice in flats or am I putting myself at risk of an injury.

I know this is kinda late, but better late than never. Im considering training in flats as well. Im experimenting with the idea this week. My running friends are telling me im crazy, but ive been injured many times with 13oz clunkers with motion stability, blah, blah, blah....all that good stuff.

I think that lightweight trainers or flats might be good, even for distance runners.

Discuss...

Check out the Pose Running Method, or Chi Running. These running styles promote that our bodies were engineered to be barefoot, and we run best barefoot. They state that these big clunky shoes are actually bad for us. Read The Pose Running Method book and reintroduce your body to running - the right way. Most of us need shoes to protect us from glass, sharp rocks, etc. as our feet are not tough enough, but we only need a minimal amount of shoe.
I have been running in Saucony Kilkenny XC2 flats for all of my running for a month now (8 miles longest single run so far) and I have had no feet or knee issues, and I am a 240 pound runner.

i dont know about competing in flats, but some training shouldnt hurt.

We train (jumping) in flats for all of the off season and still do basic work in them during comp.
as for competition, i personally wouldnt as there is such a great disadvantage when racing

Train in trainers. Race in flats/spikes.