Quote from Rafick on May 25, 2026, 1:26 am

Something I see regularly on group hikes is worth writing about. Hikers much younger than me — people in their 40s and 50s — walking up hills at heart rates of 90% or more of their predicted maximum, and feeling completely fine while doing it.

That's the catch. When you're fit and motivated, your body lets you push into territory it shouldn't be in, and you don't notice. The legs keep moving, the breath comes, the conversation continues. But under the surface, something different is happening — and on a single day it's recoverable, on three or four days in a row it isn't.

For context: I'm 74. On a typical hike my max heart rate stays around 148 bpm. I can push to 170 if I want to, but on the trail I deliberately stay under 150. There's a reason.

What those numbers mean

A rough rule for predicted maximum heart rate is 220 minus your age. It's not exact, but it's a useful guide. So:

• At 40, predicted max is around 180
• At 50, predicted max is around 170
• At 74, mine is around 146 — though because I'm a lot fitter than my biological age, my real max is higher, and I still choose to sit below 150 on the trail

When you hike at 90%+ of your max heart rate, three things happen. Your body shifts from burning fat to burning glycogen, which runs out fast. You stop being able to hold a conversation. And if you keep it up for hours, especially on consecutive days, you're not hiking anymore — you're racing. Bodies break under racing. They don't break under hiking.

The zone you actually want to be in

Endurance research is consistent on this: long-duration efforts should sit in what's called Zone 2 — roughly 60 to 70 percent of your maximum heart rate. At that intensity:

• You can hold a conversation in full sentences
• Your body fuels itself largely from fat, which is effectively unlimited
• You can keep going for hours, day after day
• You finish the day tired but not wrecked

The simple test on the trail: if you can't speak in full sentences, you're working too hard. Slow down until you can. That's it. Even without a watch, that one rule will keep most hikers out of trouble.

Why this matters for multi-day hikes

A single hard day at high heart rate is recoverable. Three or four days at high heart rate — Te Araroa, the Great Walks back-to-back, anything serious — is how people end up cooked by day three. Or worse. The hikers who finish long trails aren't the ones who push hardest. They're the ones who pace lowest.

If you're walking Te Araroa, the Camino, the Routeburn–Kepler–Hump Ridge in a row, or any multi-day track, your job on day one is not to feel strong. It's to finish day one with enough left for day two. The heart rate watch tells you whether you've done that, in a way that your legs don't.

Practical suggestions

1. Wear a heart rate monitor for at least a few hikes. Watch what it does on climbs, on descents, when you talk, when you stop. You'll learn your own body fast.
2. Find your conversation pace. The pace at which you can talk in full sentences is, for most people, very close to the top of Zone 2.
3. Slow down on climbs. This is where almost everyone overcooks themselves. Short steps, slow rhythm, breathe through the nose if you can. The hill will still be there if you go up it slowly.
4. Don't compete with the group. If the group's pace puts you above your zone, drop back. The person at the front isn't necessarily doing it right — they may just be younger, or running on adrenaline they'll pay for tomorrow.
5. Trust the watch over your ego. Especially on day one of a multi-day trip.

I'd rather see every member of this group finish their long walks tired and happy than have to make a call to search and rescue. The 50% rule I wrote about recently is one part of that. Heart rate management is the other.

If anyone wants to share their own data or has questions about specific tracks coming up, post below.