Hi, I am currently a senior in high school. I, 4 times a week, have to climb the stairs from the 1st floor to the 5th floor as quickly as possible. I also have to, 5 times a week, climb from the basement to the 5th floor as quickly as possible. For the past few months, by the time I get to the 3rd floor, my legs get really heavy. They kinda tingle. I have to stop a few times just to give my legs time to relax, but never enough to fully relax due to the time restraints. It has also been getting worse. Additionally, whenever I do the pacer- be it this year or last year, etc.- the same sensation occurs. After 10 or so times crossing the gym floor, my pace slows down and I have to drag my feet. I usually stop, not because I m breathing heavily, but because I just can t move my legs anymore. Is this normal? o.0