Why is swimming so hard?  Laura Cherchuck,  sent me a few questions after the last article about swimming asking why it's so tough.  After all, Laura has won Rachel Carson and many other Ultra Marathons. Last year she finished the Philly Marathon in a 3:16 and was one of the top women to finish the race.  She's incredibly fast and has amazing endurance, but when she gets in the pool, she's exhausted after swimming 50 yards.  She's frustrated by the entire experience.  How can she run for so long and she can't swim up and back in a pool without felling like she may die or drown?