The thing that fools a lot of athletes about HIIT-focused training systems is that they produce rapid results initially. But the results doesn’t last, and then went. Among the latest athletes to fall for the fool’s of HIIT-focused training is Daniel Kupres, 36, a married pharmacist from Palos Hills, Illinois, who did his first marathon and his first triathlon in 2018, and was hooked. However, he says, “I started with a different training system that focused more on high intensity. I initially responded well, but [then I] hit a plateau. I signed up for my first 70.3, and I knew I needed something different. Having read (and loved) The Endurance Diet, I bought the 80/20 Triathlon book and decided to give the system a try.”

The results blew Daniel away. After following the Level 1 Ironman 70.3 plan, he crushed his goal in his debut race at that distance, stopping the clock at 4:45:17 in Michigan in September. And although the training was challenging, Daniel felt energetic from start to finish, paying no cost whatsoever in his life beyond athletics.

His advice for you? “Trust the system, execute the plan, enjoy the results.”