The 7 Biggest Tour du Mont Blanc Mistakes

The Tour du Mont Blanc has no altitude problem, no permit, no summit, and a bed every night. People read that and plan it like a long walk. The Tour du Mont Blanc mistakes that end treks come from exactly that reading, and most of them are made months before the first day out of Les Houches.

The loop runs almost 170 km (105 mi) through France, Italy and Switzerland with about 10,000 m (32,800 ft) of climbing, and because it’s a loop, the same again in descent. The official season is mid June to mid September. A count from summer 2025 put it at around 75,000 hikers. Those four facts explain most of the seven mistakes below.

Mistake 1: Booking the huts in spring

Refuge bookings through the Tour du Mont Blanc wardens’ association open on October 15 for the following summer. By spring, the huts with the smallest capacity at the most popular stages are gone for July and August, and the itinerary you planned around them collapses into whatever is left.

The fix: follow the official site’s advice and book the stages with the least capacity first, then build the rest of the route around them. Do it in October or November, not April. If you’re going with a guided company, understand that guides are already booking a year ahead, which is one reason the small huts fill so early.

Then there’s 2027. In mid September 2026, French municipalities, state services, hut wardens, guides and campsites agreed in principle on new rules for the French section between Vallorcine and Les Contamines-Montjoie: through-hikers would need a confirmed booking for every night, in a refuge, hotel, campsite or authorized bivouac area, with proof checked on the trail. A charter is being drafted and the target is spring 2027. It is not law yet, and Italy and Switzerland have not committed. Whether or not it passes, the advice is the same: book every night, and book early.

Mistake 2: Showing up in June because the huts are cheaper and quieter

The cols on the loop sit between 2,300 m and 2,700 m.

Col	Altitude
Col du Bonhomme	2,329 m (7,641 ft)
Col de la Croix du Bonhomme	2,479 m (8,133 ft)
Col de la Seigne	2,516 m (8,255 ft)
Grand Col Ferret	2,537 m (8,323 ft)
Col des Fours and Fenêtre d’Arpette (variants)	about 2,665 m (8,743 ft)

In a normal year those passes carry snow into late June, and in a big snow year, into July.

Snow on a col isn’t dangerous on its own. Snow on a steep col at 7 a.m., frozen, with trail runners on, is how a walking holiday turns into a rescue. Early season also means some huts aren’t open yet, so the itinerary has gaps where a bed should be.

The fix: if June is the only window, carry microspikes, start passes late enough that the snow has softened, take the low variants, and check hut opening dates one by one. If you have the choice, go from July onward, when the cols are usually clear.

Mistake 3: Training for one big hike

A typical TMB day is about 1,000 m (3,300 ft) up and about 1,000 m down, and you do it ten or eleven days in a row. No single stage is brutal. What wears people down is starting the sixth on legs that haven’t recovered from the fifth.

Training with one long weekend hike and six days of recovery doesn’t prepare you for that, because the loop doesn’t give you the six days. What gets you round is back to back durability: consecutive training days, time under the pack you’ll carry, and the ability to start day five stiff and settle into it.

The fix: train two days in a row every week for the final two months. A loaded hill walk on Saturday and a stair or hill session on Sunday is enough to start. If you’re over 50, space the rest of the week around those two days instead of stacking hard sessions.

Mistake 4: Packing like a backpacker

The huts serve dinner and breakfast, provide blankets and hut shoes, and require a sleeping bag liner rather than a sleeping bag. Plenty of people arrive with a 15 kg pack holding a tent, a stove, a sleeping bag and three days of food for a route where they’ll sleep in a bed and eat a cooked meal every night.

Every extra kilo is carried up 10,000 m and down 10,000 m. Carrying 15 kg instead of 8 kg puts seven extra kilos on every step up and every braking step down for eleven days, and the knees take most of it on the descents.

The fix: if you’re hut to hut, pack for it: liner, layers, rain shell, a lunch for each day, blister kit, and the lightest pack that holds it. If you’re camping, that’s a different trip with a different pack, and under the proposed French rules, a tent is only allowed in designated areas with toilets and water, booked in advance, with a fee.

Mistake 5: Starting late on pass days

Summer afternoons in the Alps produce thunderstorms, and the cols are the most exposed ground on the route. The pattern repeats most weeks of the season: clear morning, cloud building by noon, lightning by two or three.

The fix: be over the col before the weather builds. That means leaving the hut at first light on pass days, eating breakfast at the hour the hut serves it rather than the hour you’d prefer, and treating a 1 p.m. arrival on a 2,500 m col as a planning failure rather than a lunch spot.

Mistake 6: Taking the hard variants on the wrong day

The TMB has alternatives at several stages, and the famous one is the Fenêtre d’Arpette between Champex and Trient. It tops out near 2,665 m (8,743 ft) through a boulder field and is widely called the hardest single stage on the loop. The alternative over the Bovine route is lower, gentler and pretty.

People take the Fenêtre because it’s on the list, on the day they’ve already walked five stages, in weather that’s closing in, on legs that are done. The variant is the right choice on a clear morning with fresh legs. On any other day the Bovine is the smart one, and nobody at the hut that night will think less of you.

The fix: pick variants by the forecast and the legs you have that morning, not by the plan you made in February. The same goes for the Col des Fours high route out of the Croix du Bonhomme.

Mistake 7: Treating 10,000 meters of downhill as free

The 10,000 m of climbing is on every route profile. Because it’s a loop, you also descend every one of those meters, under a pack, often on the afternoon half of a long day. Each downhill step is a braking contraction. The quads lengthen under load, and that eccentric work damages muscle more than climbing does. That’s why knee complaints often start around day three, and why the long drops into Courmayeur and Les Contamines are where people start limping.

The fix: train it. Slow step-downs off a box, split squats with a slow lowering phase, and loaded walks that finish downhill, in the final two months. Use poles on the route; they take a real share of the braking load off the legs. And check your boots for blister trouble on long descents before you fly, because descents are where feet slide forward in the boot.

The Tour du Mont Blanc mistakes that are decided in October

Four of the seven are settled before you leave home: when you book, when you go, how you train, and what you pack. The other three are morning decisions on the route, and they’re easier to make well when the first four were handled, because you’re rested, under a light pack, and over the col before lunch.

The same pattern we found on Everest Base Camp holds here: the trail is walkable, and almost everything that ends a trek on it was decided months earlier.