training intensity

This article was made possible through the generous support of our voluntary subscribers.  If you would like to see more articles like this one, please support FasterSkier with a voluntary subscription.   About two years ago, I started asking myself if we could define training zones in a better way. Since then, I’ve looked at just about every model out there. From a metabolic perspective, the 3-zone models tries to anchor the zones on metabolic events.  But...