Packing essentials for the TMB

Pack light and smart. Only bring what you need.

When we were preparing for the Tour du Mont Blanc, we read everything we could find: forum threads, gear lists, social posts from people who had just come off the trail. All of it was useful. None of it replaced the lesson you only learn by carrying a pack over a col.

Here is the thing nobody tells you clearly enough: every gram you pack, you carry uphill for eleven days. The instinct is to prepare for every scenario. The reality is that the scenario you should prepare for is 'I have to climb 1,000 metres again tomorrow morning on tired legs.'

The single biggest mistake: bringing a sleeping bag

Every refuge on the TMB provides a mattress, a pillow and a blanket. What they require is your own sleeping bag liner, and most will refuse you a bed without one. A silk liner weighs about 120 grams and packs down to the size of an apple.

A sleeping bag weighs between 800 grams and 1.5 kilos, and you do not need it. Leaving it at home is the largest weight saving available to you, and it costs you nothing in comfort. This is the most common and most expensive packing error on this trail.

Aim for 7 to 9 kilos

A well-packed TMB rucksack, refuge-based, comes to 7 to 9 kilos including water and food. That is the honest number. Over 11 kilos means you are carrying something you do not need.

The rule of thumb is to carry no more than 20% of your body weight, and to aim closer to 15%. For a 70 kg walker that is a ceiling of 14 kg and a target of about 10 kg. Above roughly 20% your gait changes, your centre of gravity shifts back, and your knees absorb load they were not designed for. On one day you get away with it. Over eleven consecutive days with 10,000 metres of descent, you do not.

The five things people wrongly bring

A sleeping bag (800 g to 1.5 kg). Covered above. Bring the liner instead.

Too much water (1 to 2 kg of unnecessary load). People fill three litres at the refuge and carry it past four streams and a village fountain. Learn where the refills are and carry to the next one, not to the end of the day.

Heavy camp shoes (500 g to 1.2 kg). You do need something for your feet in the evening, because refuges make you take your boots off at the door and your feet need eight hours out of them. But it should weigh 200 grams. Foam sandals, not trainers.

A camera body with lenses (1 to 2.5 kg). This is a real decision rather than a mistake, but make it consciously and trade it against something else. If you bring the camera, cut a kilo elsewhere.

Too many clothes (1 to 2 kg). The instinct is one outfit per day. The reality is two base layers and three pairs of socks, washed in the sink each evening with the soap you were already carrying. Eleven t-shirts is ten dirty t-shirts carried uphill.

Three things people forget

Earplugs. Not optional. Dormitories sleep six to twenty people and someone always snores.

Camp shoes. Most lists call these optional. They are not, for the reason above.

Cash in two currencies. The route crosses into Switzerland. Many refuges have no card machine and no signal for one. Carry euros and Swiss francs.

Weigh it before you fly

Put your packed rucksack on a bathroom scale. Not an estimate, the actual number. Then take out a kilo. You will not miss it, and on day six you will be glad it is gone.