This comes to us from Nate S. He has been meeting up with us for our stair/kettlebell workouts at Swallow Cliff Woods here in Illinios. Nate is big into KBs, SBs, and a whole lot of other odd-object lifting.
Men: Want to Expand Your Lifespan by 10 to 15 years? by Marty Gallagher
The article talks a lot about INTENSITY. And it talks about it in measurable and quantifiable ways.
There is more from Marty on his website at http://www.martygallagher.com/