My gear for the GR20

What volume for your style of night

Volume should follow your level of self-sufficiency, not the other way around. In a refuge with half board, 35 to 40 L is enough. In a tent or bivouac, with a warm sleeping bag, a mattress and a stove, count on 45 to 55 L instead. Going too big just gives you permission to fill it.

The adjustment that changes everything

A well-adjusted pack puts 70 to 80% of the weight on your hips, not your shoulders. You tighten the hip belt first, over the top of the pelvis, then the shoulder straps, then the load lifters. Poorly adjusted, even 8 kg will wreck your shoulders on the very first climb.

Ventilated or close-fitting back

A tensioned mesh back panel limits sweating on the long, shadeless climbs of the North. A close-fitting back stays more stable and tucked against the body on technical sections and ridges. It’s a trade-off between coolness and precision.

What I’d aim for

• A volume of around 40 to 50 L depending on your self-sufficiency, your sleep system and your style of night.
• A proper hip belt, because it takes the load off your shoulders on long days.
• A breathable back panel, useful in summer when the climbs come one after another with no shade.
• Compression straps to stabilise the load on technical sections.
• A rain cover or a waterproof inner liner to protect your sleep system.
• Accessible pockets for water, phone, sunscreen, sunglasses and snacks.

The classic trap

Choosing a pack that’s too big makes you want to fill it. On the GR20, that extra margin costs you every single day. I’d rather have a sensible volume, packed in advance, then tested fully loaded on a real outing before setting off.

Priorities

Grip, stability, protection and comfort. A reassuring sole beats a model chosen purely to shave off a few grams.

Trail, hiking or mid

A sturdy trail shoe works well if you’re light, fit and comfortable on rock. A mid hiking boot is more reassuring under a heavy load or on long, jarring descents.

Low or mid cut?

A low cut offers freedom and lightness for an experienced hiker. A mid cut supports the ankle if it’s weak, or if you’re carrying a heavy load on unstable ground.

The sole

A lugged sole with a grippy rubber (Vibram-type) makes the difference on slabs and on the wet rock of the North. Good rigidity protects the arch of the foot on long days over scree.

Socks and blisters

Technical anti-friction socks, no cotton, changed or turned inside out at midday. A seam that rubs or a damp sock is all it takes to start a blister.

Breaking them in

Several loaded outings before you leave, on the climbs and especially the descents. A size that allows for your foot swelling at the end of the day and in strong heat will save your toenails.

Refuge, tent or bivouac

This is the choice that determines everything else. In a refuge, a sleeping-bag liner can be enough in summer. In a tent or a bivouac, you need a real sleeping bag, an insulating mattress and enough to handle a cold night at altitude.

Bag or quilt: temperature

I’d aim for a comfort rating of around 5 to 10 °C depending on the season and how easily you feel the cold. In May, June, September or October, I’d allow more margin. The quilt saves weight; the bag protects better against the cold.

The cold at altitude

Even in high summer, the refuges are often between 1,400 and 2,000 m. Nights can drop close to 5 °C, and the wind makes it feel colder still. Underestimating this means sleeping badly and recovering badly.

The mattress and R-value

R-value measures insulation against the cold ground. For the GR20 in summer, an R-value of 2 to 3 is generally enough. A light inflatable mattress or a reliable foam pad makes a big difference to recovery.

Packed size and weight

The sleep system is one of the biggest volume items, along with the tent and clothing. A down sleeping bag compresses better; synthetic fill copes better with damp.

Liner, pillow, details

A sleeping-bag liner is useful in a refuge or for hygiene. For a pillow, a light inflatable model or some clothes rolled up in a fleece is more than enough.

Layer 1 — next to the skin

The t-shirt against your skin wicks away sweat. Merino regulates temperature and keeps odours down over several days, but dries slowly. Synthetic dries faster but smells sooner. Never cotton.

Layer 2 — insulation

A light fleece or a lightweight down jacket for breaks, windy summits and evenings at the refuge. Compact and warm for its weight, it’s the piece that keeps you dry and warm when you stop.

Layer 3 — protection

A reliable waterproof, windproof jacket. At altitude, a storm can break fast and the wind makes it feel far colder. This is a safety item, not a luxury: you never leave it at home.

The useful basics

• One breathable t-shirt worn and one spare t-shirt.
• A light warm second layer: thin fleece or down jacket depending on the season.
• A reliable waterproof/windproof jacket.
• Shorts or light trousers, depending on the season and how well you tolerate the cold.
• Quality socks, a cap or hat, and a buff against sun, wind and sweat.

What I’d cut back on

Spare clothing should stay measured. You don’t need a clean outfit per day: you need pieces that dry fast. Cotton is to be avoided, because it dries poorly, holds moisture and quickly becomes uncomfortable.

How much to carry

In normal conditions, 1.5 to 2 L between two water points. On a long, exposed ridge stage in full heat, I go up to 2.5 or even 3 L. A little extra weight beats rationing under the sun.

The exposed stages

Some ridge sections, especially in the south, offer neither shade nor water for hours. They’re the ones that dictate your reserve, not the average for the day.

Where to top up

Most refuges and bergeries have a water point. But between them, there may be nothing reliable. You fill up whenever you can, without waiting until you’re running dry.

Bladder, bottle or flask

A hydration bladder nudges you to drink regularly without stopping. A bottle or flask helps you see exactly how much is left. Many people combine the two for comfort and tracking.

Tablets or filter

Tablets are light and safe, but slow and strong-tasting. A light filter gives you immediate, pleasant water. Either one is reassuring if you’re drawing from a stream or an untreated spring.

Drink before you’re thirsty

On hot, exposed stages, thirst already lags behind your real need. Drinking regularly in small sips stops you chasing dehydration all afternoon.

Why the battery drops

GPS, a bright screen in full sun, the cold of the night and, above all, the search for signal in areas with no coverage drain a battery far faster than in town. It’s airplane mode that saves your battery life.

Which power bank

A 10,000 mAh power bank recharges a smartphone roughly two to three times: enough for several days if you manage it well. For twelve days with no reliable outlet, some go up to 20,000 mAh, at the cost of weight.

Navigating offline

Maps and GPX tracks downloaded in advance and checked before you leave. Offline navigation doesn’t depend on signal and uses little power. That’s your real navigational safety net, not the mobile connection.

What I’d take

• Smartphone with maps and tracks downloaded offline.
• A GPS watch or a reliable app to track effort and route.
• Power bank, short cable and a mini wall charger.
• A headlamp — essential for an early start, a late arrival or a tricky night.

The good habit

Airplane mode whenever possible, sensible brightness, offline tracks and battery kept in reserve. I’d never rely solely on the network to navigate or to raise the alarm.

Feet and skin

Blister plasters (second-skin type), tape or strapping, anti-chafe balm, antiseptic and SPF50 sunscreen. On the GR20, it’s the feet that give out first, long before the legs.

The anti-blister kit

The most important part of the kit. Hydrocolloid plasters, tape to protect a hot spot the moment you feel it, small scissors and gauze. You treat a red patch straight away, never once the blister has formed.

Pain and joints

A common painkiller if you tolerate it, an anti-inflammatory on medical advice, and a bandage or strap to support a tired ankle or knee on long descents.

Stomach and the unexpected

Anti-diarrhoea medication, rehydration salts and your personal medication in sufficient quantity for the whole crossing. There’s no pharmacy between two refuges.

What genuinely gets used

A small, well-thought-out kit beats a big one that’s never opened. Plasters, tape, painkiller, sun protection and personal medication cover the vast majority of the real niggles on the trail.

The safety basics

A survival blanket, a whistle, useful documents in a waterproof pouch, a little cash and enough to handle an unexpected event or an unplanned night.

How much to eat

A big GR20 day can burn 3,000 to 4,500 kcal. There’s no way to make up all of it while walking, but you have to avoid the deep deficit that cuts your legs out from under you by day three. You eat often, even without much appetite.

Easy to eat

Bars, dried fruit, nuts, biscuits, fruit purées or any other snack that goes down quickly, even when the heat and the effort have closed your stomach.

Saltier options

Cured sausage, hard cheese or the equivalent if it holds up in the heat. Salt and electrolytes help replace what you lose through sweat on the big days.

Resupply

Few stages allow a proper restock. Vizzavona, at the halfway point, cuts the GR20 in two and remains the most convenient spot. Haut-Asco and Castel di Vergio also help out. Between these points, you carry everything.

When your appetite goes

The heat and the effort often close your stomach in the middle of the day. Sweet and liquid foods (fruit purées, drinks, dried fruit) go down better than heavy savoury fare. The aim: take in energy even without hunger.

The safety reserve

I’d always keep a small margin: a bar and one freeze-dried meal in reserve. A delay, a storm, a full refuge or a stop further on than planned all happen fast.

Carrying and feet

• A comfortable pack that isn’t too big.
• Shoes already tested.
• Poles, if you already use them or your knees appreciate them.

Protection

• Buff and cap.
• Breathable clothing.
• A reliable rain jacket.
• A simple, robust water system.

Practical safety

• Headlamp.
• Power bank.
• Blister kit.
• Offline maps and tracks.

Weight and duplicates

I’d cut clothing weight even further, avoid pointless duplicates and be wary of “just in case” items that are too heavy, especially if they’re neither used often nor there to manage a real risk.

Preparation

I’d test some items more before leaving, in particular the loaded pack, the shoes on descents, the rain jacket and the way I split food and water across the stages.

Untested gear

• Setting off in brand-new shoes.
• Not testing your pack loaded.
• Relying too much on your phone or the network.

Pointless weight

• Taking a pack that’s too heavy.
• Carrying too many clothes.
• Adding “just in case” items with no real use.

Underestimated risks

• Neglecting the heat.
• Forgetting sun protection.
• Underestimating the descents.
• Forgetting blister prevention.