How Rémi Bonnet Trains (2,194 Metres of Climbing an Hour)

At Fully in Switzerland, Rémi Bonnet climbed 1,000 vertical metres in 27 minutes and 21 seconds, taking a minute and a half off a world record that had stood for years. The course is 1.92km long with an average gradient over 50%, which is steep enough that running mechanics stop working and the movement becomes something closer to ski mountaineering without the skis.

Divide it out and you get the number that describes him: roughly 2,194 metres of climbing per hour.

Why vertical ascent rate is the honest metric

On flat ground, speed is a reasonable proxy for fitness. On a 50% gradient it is not, because almost none of your power is going forwards. It is going up, against gravity, and the only thing worth measuring is how fast the altimeter moves.

Vertical ascent rate strips out terrain, distance and pace and leaves the actual work. For scale:

• A fit recreational hiker moving well: 600 to 800 m/h.
• A strong amateur mountain runner or skimo racer: 1,000 to 1,300 m/h.
• World class: 1,800 m/h and up.
• Bonnet at Fully: about 2,194 m/h.

Because the work is almost pure vertical lifting, it is also the most brutally honest expression of watts per kilogram in endurance sport. Every extra kilo is a kilo lifted a thousand metres. This is why the same handful of athletes dominate uphill running and ski mountaineering at once. Bonnet won the overall, individual and vertical titles in the 2025-26 ISMF World Cup and races mountain running in the summer, the same crossover Kilian Jornet built a career on.

Zones for a sport with no downhill recovery

Ski mountaineering made its Olympic debut at Milano Cortina 2026, in sprint and mixed relay formats. It is an unusual endurance sport in one respect: in a vertical race there is no flat, no descent and no coasting. The intensity never drops, which means pacing errors are not recoverable.

That changes what your zones are for. In a sport with rolling terrain you can bank a mistake and pay it back on a descent. Going up for 27 minutes straight, you cannot.

Set your skimo zones from a tested maximum heart rate, and note that heart rate runs higher for the same perceived effort when you are using poles and arms as well as legs, the same as it does in cross-country skiing.

Work out your own vertical rate

You do not need a race. Find a steady climb you can repeat, ideally 20 minutes or longer, and measure it properly:

1. Take the elevation gain, not the distance, from a mapping tool rather than a wrist barometer, which drifts.
2. Take the time for the climb only.
3. Vertical metres per hour = gain ÷ time in hours. A 400m climb in 25 minutes is 400 ÷ 0.4167, so 960 m/h.

Repeat it a few times a season on the same climb, in similar conditions, and you have a fitness test with no lab and no power meter. It is the mountain equivalent of an FTP test, and on steep ground it is more informative.

What we can and cannot say about his training

Bonnet's week is not published, so this is not a place to invent one. Two things are on the record and both are worth having. He has run the Fully course more than fifty times in training and racing, which is a lot of specificity on one climb. And his days start with farm work, tending goats and carrying hay, which is not a training plan but is a reminder that the strength underneath mountain athletes is rarely built in a gym alone.

The crossover is the real lesson. Skinning up glaciers in winter and racing uphill on foot in summer are the same engine expressed two ways, and neither season is an off-season.

What you can steal from it

• Measure vertical, not pace. On any gradient over about 15%, metres per hour tells you what pace cannot.
• Repeat one climb. The same hill, a few times a season, is a better fitness test than any formula.
• Weight is not a vanity metric uphill, it is physics. But fuel the work first. See Jessie Diggins for why that comes before anything else.
• Use poles and expect a higher heart rate. Whole-body work runs hotter at the same effort, so anchor your skimo zones to a real HRmax.
• Seasons can feed each other. Uphill running in summer and ski mountaineering in winter are one training year, not two.

More in this series: Kilian Jornet, Courtney Dauwalter and Johannes Klæbo.

Sources

• Red Bull on the vertical kilometre world record
• Marathon Handbook on the record
• 2025-26 ISMF World Cup
• Vertical kilometer
• Outside on skimo's Olympic debut

Cover photo by Johann Conus, CC BY-SA 4.0, via Wikimedia Commons.