[Brian Bauer]

a year ago I moved from sea level to the mountains of Montana.  it took many months to get my head around the data and number associated with training and racing at altitudes of 7,000 – 14,000ft.  it can be very confusing.  for starters, and most important, you need to know what your zones “feel like”.  what do easy Z1 and AeT feel like at sea level?  being in tune with those feelings is critical when you get up high….and that is because your HR will change with altitude.   your AeT at sea level might be  130, and your AeT at 10,000ft might be 110…but the feeling should be the same.  think of it like this: Economy = Oxygen converted to Velocity.  at sea level, you need a certain amount of oxygen to move at a certain pace.  At higher altitudes, one of 2 things will happen: 1) you will be moving at a slower pace and therefore requiring less oxygen and your HR will be lower 2) you will be moving at the same pace and working much harder resulting in a higher HR.  in general, AeT drift tests are altitude dependent.  an AeT test done at sea level does not directly apply to 10,000ft.  the best thing that you can do is get super familiar with you feel in your zones.  feelings traverse altitudes, numbers do not