Has anyone tried this
http://fellrnr.com/wiki/DIY_Altitude_Training#What_you_will_need
system?
Doesn't seem too complicated, but I was just wondering if anyone had tried making it themselves.
Has anyone tried this
http://fellrnr.com/wiki/DIY_Altitude_Training#What_you_will_need
system?
Doesn't seem too complicated, but I was just wondering if anyone had tried making it themselves.