This is my third time on my school's track and field team and I want to actually do well this year. In previous years, even with all the training we do (3 times a week, two hours at a time for a couple of months), I still wasn't in the best shape by the end of the season. It isn't so much that my muscles get tired (I think... could be wrong I guess), but I seem to feel tired in my chest more than anything. I do have asthma, but that doesn't affect me that much as long as it's warm outside.
Anyway, my question is this:
Is there any way I can raise my heart rate for a fairly long time without working any muscles too hard as we do in practice? I'm usually sore the day after practice and I'd rather not make it worse, but I do want to increase my endurance and level of fitness.
Is there any way to achieve this? Am I completely wrong about what endurance is?
Thanks

