I've been trying to make sure I run a lot of my miles easy(7 min+pace) because i have a history of running my runs too fast. But for some reason when i run my easy runs at like 7:10 pace i feel horrible. Like it's in my head where I feel really tired and feel like I need to sit down and nap. But like today I did a 6 miler at 6:13 pace and felt amazing. Didnt have that feeling at all and felt like I could of gone for another 4 miles. I know I'm not supposed to do my runs that fast but i feel good doing them and i dont know what else to do. If someone could give me some advice that would be great!
Other info that might be good:18 y/o Male. Senior. 5k xc pr-15:48, 3200 pr-9:39, 1600 pr-4:35