A few years back Laurence participated in the New York City Triathlon. He did well but didn’t win his age group. Three years later, he finished 24th overall in the New York City Triathlon overall and finished first in his age group, 45 to 49. He beat his nearest competitor by over five minutes.
He attributed a large part of his success to HIIT, high intensity interval training, a strength/cardio workout taken to a deep fatigue. He had been doing it four years along with his usual swimming, running, biking, and kayaking. His times in triathlon events came down. The strength training program enabled him to spend less time on his bike and in the pool. More time for recovery resulted in continuing improvement.
I am stronger, recover faster and only devote 30 minutes a week to weightlifting. It is like discovering the fountain of youth. It really does work.