Thurs - Are the legs back to normal yet!? If you are feeling good again your can attempt a tempo run during a 5-7 mile run. Warm up at least 2 miles before going straight into a 1 min, 2 min, 3 min, 2 min, 1 min tempo session with equal time recovery after each segment. This should be run at your goal 5k pace, I know it seems fast, but it's only 9 min of a 5k, so it should be done at the race 'intensity' you seek to run. You'll have no idea what the pace is unless you do it on a track, not necessary, but you know how the miles felt in the race so base it on that. 2-3 miles of cool down after the tempo part. This is a continuous workout from start (warm up) to finish (cool down) so you shouldn't have to stop or walk to or stretch or anything.