✔ 最佳答案
If your problem is speed, do speed workouts. eight 400s with little rest in between. Try and make each 400 consistent. If your problem is endurance, run at a medium pace for an hour straight. Every five minutes, run harder for an hour. If you feel ready to die at the end, then you've done it right. This really works, I shaved three seconds off of my 400 time, running a 53.9 when only a month ago I was running a 56.8. Good Luck!