For a long time (and honestly, still to this day), I was an absolute believer in the Zone 2 theory, which gained mainstream popularity through Dr. Iñigo San Millán (then coach of Tadej Pogačar). The way I interpreted his theory, Zone 2 was the absolute gold standard. Just look at Tadej’s famous podcast with Peter Attia: he explains his Zone 2 hovers around 300 Watts with a heart rate of barely 150 beats per minute. How on earth do you beat someone like that? He saves the vast majority of his glycogen to strike lethally at the end or on the steepest climbs by just throwing an extra layer on top.