"Zone 2" does burn a higher percentage of fat during the effort itself, but overall fat loss depends on total calories burned across the day, not the intensity zone — and walking and running burn very similar calories over the same distance. It's not a shortcut to weight loss.

noli's read

Stripped of its "myth-test" format, the core zone 2 claim is well-founded and consistent with the Storoschuk et al. (2025) review: yes, at zone-2-type intensity the body proportionally burns more fat as fuel during the effort — but body-fat loss over time depends on total daily calorie balance, not the percentage of fat burned during one specific session. That's a correct technical distinction, frequently blurred in fitness marketing. The other test reported (walking vs. running over the same distance) is consistent with exercise physics: over an identical distance, the mechanical work and therefore total calorie cost are close, even though per-minute intensity differs — which is why several studies find walking and running comparably effective for weight loss at matched distance. The video's format (before/after measurements, metabolic cart) is a reasonable methodology for this kind of comparison, even though it's popular-science content rather than a peer-reviewed publication itself.

the sources

1. 1Rosenblat MA, Perrotta AS, Vicenzino B 2019
2. 2Silva Oliveira P, Boppre G, Fonseca H 2024
3. 3Menshikova EV, Ritov VB, Ferrell RE, et al. 2007