Saw this on twitter, I like the summary and the breakdown of the intensity levels.
http://www.joefrielsblog.com/...training-update.html
Quote:
So what did the researchers find out when they tested the athletes after the 9 weeks of training and compared the results with their pre-tests? The group of subjects who showed the greatest physiological and performance benefits were in the polarized group. Their VO2max increased, on average, 11.7%. Their time to exhaustion on a ramp test increased 17.4%. Peak velocity (running or skiing) and peak power (cycling) improved 5.1%http://www.joefrielsblog.com/...training-update.html