<< I started doing sprinting drills a month ago to improve my speed at tae kwon do, and ever since that first set of 10, 25m sprints I've had reoccurring pain in my quad. >>
So you have been sprinting for a whole month and wonder why your muscles are complaining. Are you doing any slow stretching or other slow warmups to get your legs ready to sprint?
And after you do this sprinting, do you follow up with any cool down stretching to get your leg muscles to relax again?
In my running days it took me weeks to work up to jogging any distance, much less sprinting.