This time from Mark Hekman:
"But at the same time, I finally got a power metre [sic] and started training with that and it changed everything," he said. "I've never been so in shape in my life.
"I've never been this fit - I lost 13 pounds from my race weight of last year, so I might go fast this year...I paid attention to the little things - diet, not drinking and doing all the intervals.
I've been training with heart rate, and I was doing them all wrong. I'd go out too hard and then blow up. I was missing the benefit of the latter part of the interval." (emphasis mine).