So I'm heading into my junior year of high school right now, and I want to start picking up my off seasons. I primarily focus on 400m and 800m, but I do cross country in the fall. I'm not looking to increase my speed, but merely maintain my speed level and not lose it during cross country. Can anyone advise some workouts for me to do over the summer? I do long runs with the cross country team tuesday and thursday mornings. My 400m PR is just under 54 seconds and my 800m is about 2:10. Any feedback is appreciated.