id really hit the dynamic stretching before the workouts.
im new to sprinting but not new to athletics and i feel that i really need to do alot of butt kicks, high knees and a decent amount of lunges before my workouts to get going.
also even before i attempt 100% acceleration or max speed workouts i do 1 or 2, 200s at 80ish% so i dont just shock my body.
id say work into it a little more, no amount of warm ups can imitate the stress of full sprinting so try a good dynamic stretching session before ur workout than some warm ups of whatever distance ur running at 50%, 60%, 70%, 80% 90% than do ur workout. wont take too much energy but will loosen the legs up.
just my 2 cents