http://www.boston.com/sports/footbal...ning_altitude/
But that difference in oxygen levels matters a lot more to athletes engaged in intensely aerobic sports such as running and bicycling than it does to football players. In long-distance sports, reduced oxygen levels can strain the heart and lungs as they work harder and harder to get enough oxygen to energy-starved muscles.
Football is what exercise specialists call an
anaerobic activity. Power is what's needed, and that comes from the glucose and other substances stashed in the body.
''In football, you have a burst of energy for 10 to 30 seconds, and then you have a break," said Dr. Arnie Scheller, a sports medicine specialist at New England Baptist Hospital and, for nearly two decades, team physician for the Boston Celtics. ''If you didn't have the recovery time, then the Denver team would definitely be at an advantage."
Even though 5,000 feet sounds pretty high for those accustomed to living in a place where altitude above sea level is measured in 10- or 20-feet increments, the truth is, people have to get quite a bit higher before worrying about serious health consequences.
''At 5,000 feet there's no question you can get a little short-winded. But these are tough guys and focused guys, so I think the likelihood of it making a difference is not that great," said Dr. Arthur Day, director of the Neurological Sports Injury Center at Brigham and Women's Hospital in Boston.