Training at high altitudes?

Question

i need a link to show why athletes train at higher altitudes.

Answer 1

less oxygen is reaching the lungs due to there being less oxygen at higher altitudes. so therefore athletes train at higher altitudes due to their cardio respiratory system having to work harder to extract oxygen from the air.
this causes the lungs and heart to work harder and when they come back down to sea level their bodies have adapted for the higher altitude and they can perform better.

Answer 2

i dont have a link but its definitely because it is harder to breathe in higher altitudes and that makes the athletes work on their respiratory system, hope this helped !!!

Answer 3

There is evidence to support and refute the benefit of high altitude vs. sea-level training.

Here's just a couple...

Answer 4

Try this.

http://www.nwrunner.com/features/02-01-03_sports_med.html
.