Speed is important in sprinting, and endurance is also important in long-distance running. 800 meters does not belong to long-distance running, nor does it belong to sprint. Pay attention to the combination of the two. According to your request, the speed is only 3 minutes and 55 seconds. If you insist on running 800 meters every day, I don't think it will take two weeks to reach your goal, because you don't need to be too fast for such a long time, mainly because your endurance is almost the same now, so it should be no problem to exercise more. I suggest you run 800 meters every day and keep running, preferably in the morning when the air is fresh and not too hot. After running, you can relax by jogging, swinging your thighs, patting and rubbing. If possible, you can drink a cup of hot tea or a functional drink to supplement the salt ions lost by your body. Personally, drinking tea is better, which is easy to quench your thirst and can quickly restore your energy. . .