04/20/2026
If you’ve been doing all the cardio but still feel yourself breaking down on hikes, this is for you.
Zone 2 cardio is everywhere right now, and the prescription is always the same: three to four hours a week at a conversational pace to build your aerobic base. It works, but it leaves out the question nobody is asking. What happens when you build a strong engine on a weak chassis? In the mountains, people rarely break down from a cardio failure. The breakdown almost always happens on the descents, where the knees, hips, and low back take the hit. That’s not an engine problem, it’s a chassis problem, and no amount of Zone 2 will fix it.
Full video is live on YouTube. OAT founder and professional mountain guide Mikey Bell breaks down the Engine vs. Chassis framework, the research behind it, and a self-test you can do from home
Watch the full breakdown: https://youtu.be/gFK3cbOL1tE