Yeah I might pace it out so see what I'm doing. I also think I'm not allowing enough rest in between sprints (which would explain the fatigue). Just reading some guides and some say resting for 4-5 minutes in some cases. It's amazing how what used to be so natural as a kid feels like a long lost skill. Just running fast. Seems easy enough. Used to run up to the shop in my action man slippers like lightning. Now it feels like I'm using someone else's body to try and run.