20/10/2026
This fitness myth could leave you dangerously unprepared for altitude.
If you're preparing for a high-altitude trek, it's easy to think the answer is simple: run more, build your cardio, get fitter, and you'll be ready.
But altitude doesn't work that way.
Cardio can absolutely help you walk longer, recover better, and handle the physical demands of a long trekking day. What it cannot do is acclimatize your body to low oxygen.
You can have excellent cardiovascular fitness and still develop altitude sickness.
What actually matters at altitude is how you acclimatize.
Control your rate of ascent — don't gain altitude too quickly just because you feel physically capable.
Watch your sleeping elevation — your body is under the most stress while adapting overnight.
Build acclimatization days into your itinerary — give your body time to adjust instead of treating every day as a push toward the next destination.
Ease into your first days at altitude — feeling fit doesn't mean you should immediately test your limits.
Above 3,000m, a commonly recommended approach is to keep your sleeping elevation gain to around 500m per day, with an additional acclimatization day for every 1,000m gained.
So don't stop doing cardio.
Just stop thinking cardio is your altitude training.
Train your fitness for the trek.
Use your itinerary to prepare your body for the altitude.
Being fit can help you trek better. It doesn't make you acclimatized.
