what effect do sore legs have on ur performance?

simple stop being a wuss, and run, if not and you let your sore legs get to you your going to run slow

Yeah just don't really worry about it. Don't let it be an excuse during the race to stop pushing, just kind of focus on racing. There's nothing really you can do right now about sore legs. Maybe try warming up a little bit longer than you usually do just to get the blood really flowing through the legs, and stretch out well (not to the point of overdoing it). After the race though, take an ice bath, roll your legs, stretch more, etc.