Gear guide
My gear for the GR20
Here is the gear I used, or that I recommend, to prepare for a full GR20. The goal isn’t to carry as much equipment as possible, but to strike the right balance between safety, comfort, weight and efficiency on the trail.
Pack weight
The main goal: travel light without putting yourself at risk
On the GR20, the weight of your pack completely changes the experience. Every extra kilo makes itself felt on the climbs, the descents, the scree fields and the technical sections. The goal isn’t to go ultralight at any cost, but to keep only what genuinely earns its place.
| Benchmark | Sensible target | My take |
|---|---|---|
| Ideal target weight | 8 to 10 kg excluding water and food if you can. | A great balance for keeping going all day without being dragged down by the pack. |
| Acceptable weight | Around 12 kg excluding water and food. | Still doable, but every descent becomes more demanding. |
| Beyond that | 12 kg and up, especially with lots of “just in case” items. | The GR20 becomes noticeably tougher, particularly in the North. |
Bottom line: every item should be used often, protect you from a real risk, or replace several other items. Everything else soon weighs more in your legs than in your mind.
Carrying
Backpack
The right pack isn’t necessarily the biggest one. It’s the one you can carry for hours, loaded, in the heat, over uneven ground, without creating needless pain.
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.
The only real test: a loaded outing at true weight, water included, with some elevation gain, before you leave. That’s where you find a pressure point, a badly placed strap or a back panel that doesn’t breathe — not at Calenzana on day one.
Feet
Footwear
Footwear is a crucial part of the GR20. The terrain is very rocky, technical and uneven, and the descents can do as much damage as the climbs.
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.
Avoid this: discovering your shoes at Calenzana. Even a very good pair can become a problem if it has never been tested loaded, on descents, with the socks you plan to wear.
Nights
Sleep system
Even in summer, nights can be cold at altitude. Your sleep system needs to stay compact, yet serious enough to let you truly recover.
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.
Bottom line: over a twelve-day effort, the quality of your sleep matters as much as the weight of your pack. A sleep system that’s a little heavier but lets you truly recover is often a good call.
Layers
Clothing
I’d stick to a simple layering system: breathable when it’s hot, protective when the wind or a storm rolls in, dry for sleeping.
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.
The three-layer rule: you add or remove a layer instead of wearing everything at once. You often start a climb feeling slightly cold: the body warms up within a few minutes, and you avoid sweating into clothes you’ll have to dry that evening.
Hydration
Water and hydration
The minimum capacity you need varies with the stages, the weather and your pace. In summer, I’d rather plan generously, especially on exposed sections.
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.
My field rule: set off with a real reserve on long, exposed sections, and never leave a sure water point betting on the next one. Dehydration ruins a day far faster than two hundred extra grams of water.
Navigation
Electronics
Electronics should help, not become a fragile dependency. Signal is patchy, the battery drains fast with GPS, photos and heat.
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.
Bottom line: electronics help, but they should never become your only safety net. An offline track, a battery kept in reserve and a minimum of terrain reading beat depending on a network that vanishes the moment you need it.
Safety
First-aid kit
I wouldn’t set off with a huge pharmacy, but I’d keep the essentials. On the GR20, a blister or a bit of friction left unmanaged can ruin several days.
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.
The reflex that saves your week: treat every hot spot the moment you feel it, at the first break, without waiting. A minute of tape at the right moment saves three days of limping.
Energy
Daytime food
I wouldn’t limit myself to the evening meals. Long days are also won through small, regular intakes: snacks, salt, sugar, fat — whatever goes down when fatigue sets in.
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.
The classic trap: packing too little food to save weight, then running out of energy on the long stages. Over twelve days, the deficit builds up. A few extra snacks beat a sugar crash mid-climb.
Lessons learned
What I’d take again
These are the choices I’d keep without hesitation, because they bring comfort, safety or real efficiency on the trail.
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.
To adjust
What I’d change
I deliberately keep this list cautious: it depends on the season, your style of night and your level of self-sufficiency. But the idea stays the same: fewer duplicates, more coherence.
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.
To avoid
The mistakes to avoid
The GR20 doesn’t always forgive repeated bad choices. Many mistakes aren’t serious on their own, but they add up with the heat, the fatigue and the terrain.
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.
Field notes
My exact kit, piece by piece
Beyond the principles, here is the exact list of what I carried on the GR20 — piece by piece, with the price, the weight when I have it, a link to the product and my honest field feedback, including what I wouldn’t take again. This isn’t a list of sponsors: just my real kit, to help you compare.
Backpack
Osprey Atmos AG 50
The Anti-Gravity suspended back panel makes a real difference on the long, shadeless climbs in the north: the tensioned mesh hugs your back and lets air flow through, so you sweat noticeably less. The hip belt transfers the load nicely onto the hips and spares the shoulders on the big days. Two honest downsides: at almost 2 kg empty it’s a heavy pack for the category, and 50 L always tempt you to fill the extra space. Set up well and packed with discipline, it stays a very comfortable companion over twelve days.
View productOsprey Ultralight Raincover Large
I never once pulled it out while walking. It only earned its place at night, during the stormy spells, covering the pack to protect it as much as possible from the rain. It’s a light accessory that only helps occasionally — but the night it really pours, you’re glad to have it.
View productSleep system
Simond MT900 1P tent
Hard to beat on value at Decathlon. Freestanding, it pitches fast even on rocky ground where driving stakes is a pain, and it holds up well in the wind — a real criterion on the GR20’s exposed cols and bivouacs. Space is tight for a one-person tent but enough to sleep and keep the essentials sheltered. Across the whole traverse it did the job night after night without flinching.
View productSimond MT500 sleeping mat
A basic foam mat, but that’s exactly its strength: impossible to puncture, you strap it to the outside of the pack without a second thought. Ground insulation stays modest, so keep it for milder summer nights. For the price and the reliability, it’s a sensible choice when you accept a little less comfort than an inflatable.
View productMillet Alpine LTK 900 sleeping bag
Comfortable even above 1,500 m, in the middle of August. The down fill compresses very well and stays warm for its weight, which is reassuring when nights in the refuges or bivouacs drop lower than you’d expect at altitude. A bit bulky once unpacked, but over twelve nights, quality sleep was well worth that volume in the pack.
View productClothing
K-WAY 4.0 rain jacket
The ultralight windproof/waterproof shell par excellence: it folds into its own pocket and you barely feel it. Perfect against passing showers and especially the ridge wind that drives the felt temperature down. It’s not a high-mountain hardshell, but for the GR20’s summer weather it’s the right weight/protection trade-off — I wouldn’t have swapped it for anything heavier or pricier.
View productNorth Face Yumiori fleece
My insulation layer for breaks, windy summits and evenings at the refuge. Warm for its weight, breathable, it works just as well under the rain jacket as standing still when the climbing sweat starts to chill. It’s the piece that kept me dry and warm every time the pace dropped.
View productNike Trail Solar Chase tee × 2
Technical breathable fabric that dries fast, built for trail running under the sun. Two in rotation: one worn, one drying, plenty for twelve days without ever feeling grim. Sweat management is good even on the long exposed climbs.
View productSimond MT500 merino boxer × 2
Merino really keeps the odours down over several days, which changes everything when you don’t wash every evening. Two boxers in rotation covered the whole traverse with no comfort or chafing issues. It dries more slowly than synthetic, but the lack of smell more than makes up for it.
View productQuechua Hike 500 merino socks 2 pairs
Two pairs in rotation: one on the feet, one drying clipped to the pack. Merino again for comfort and moisture management, no cotton to fester. Not a single blister caused by the socks over the whole route — exactly what you ask of a sock on the GR20.
View productNike Dri-FIT Trail shorts × 2
Light, breathable, quick-drying. Having two means you can rinse one in the evening and set off dry the next morning. Welcome freedom of movement on the scrambling sections and the big strides on the way down.
View productNew Era Camo cap
Decent protection for the head and face, and a style I like. Honestly, a cap with a longer peak, or even a Sahara-style model with a neck flap, would cover better on the very exposed ridge sections in the south. But this one did the job throughout.
View productD.Franklin Wind Fifty sunglasses
Comfortable and stable, they don’t move even when sweating or running downhill. On style and price, nothing to fault. The one thing I’d check before going back is the UV rating: at high altitude the radiation is harsher and deserves proper lenses.
View productFootwear
Hoka Anacapa 2 Mid Gore-Tex
Generous cushioning and immediate comfort, pleasant on the long jarring descents and the approach. But I don’t recommend them for the GR20: the sole proved too fragile for the abrasive granite and the relentless scree of the trail. On terrain this demanding, a harder, more durable sole is the better call, even at the cost of a little softness. It’s the piece of my kit I’d change first.
View productAdidas Adilette Shower camp sandals
Indispensable once the day is done: shower at the refuge, feet breathing, a relaxed evening without the big boots. Light, they slip into a side pocket of the pack. You underestimate their value until the first evening you take off your hiking shoes — that’s when you wouldn’t give them up.
View productWater & hydration
Salomon Soft Flask 500 ml × 2
Two soft flasks in the pack’s chest pockets: you drink regularly without stopping or taking the pack off, which is precious for not waiting until you’re thirsty on the exposed sections. Empty, they weigh and take up almost nothing. The perfect complement to the main reservoir.
View productCamelbak Fusion 2L reservoir
The main reservoir, with its watertight Tru-Zip that’s easy to fill and clean. 2 L cover most of the stretches between water points; on the long shadeless ridges in the south, I topped up with the flasks and the filter bottle. Drinking from the hose nudges you to sip steadily throughout the effort.
View productÖko 650 ml filter bottle
My safety net for drawing from a spring or an unmanaged stream without risk. The filter gives immediate, taste-free water, where tablets are slow and leave a taste. A bit pricey, but over twelve days in the mountains, peace of mind about water quality is priceless.
View productElectronics
iPhone 15 Plus
I never used it for navigation: on the ground I followed the GR20 waymarking and my Garmin Enduro 2 watch. The iPhone only served to take photos and stay in touch with family when there was signal. The Plus model’s big battery is still an asset for lasting several days without a socket, but in my actual use it was above all a camera.
View productGarmin Enduro 2 Sapphire Solar watch
The most-used piece of the entire traverse. Continuous GPS track, monitoring of effort, elevation and route on the wrist, and above all solar charging that makes the battery life practically endless on the GR20. Expensive, but it’s the tool that asked the least of me — I never once had to worry about its battery.
View productBelkin 20,000 mAh power bank
Excellent capacity-to-price ratio. 20,000 mAh are enough to last the twelve days when managed well: several phone recharges plus a top-up for the rest. To be counted in the pack’s weight budget, it’s the price of peace of mind when there’s no reliable socket for several days.
View productPetzl Actik 450 lm headlamp
Plenty powerful for starts before daybreak and late finishes. I used it less than expected, but on foggy mornings and bivouac nights it instantly becomes essential. Light, reliable, with decent battery life — exactly what you want from a hiking headlamp.
View productHealth & hygiene
Decathlon first-aid kit
The basic kit, compact and cheap. In practice I mostly drew on the blister plasters and the antiseptic — it’s the feet that give out first on the GR20. You hope never to open it for anything serious, but leaving without it would be a mistake.
View productUltra-compact microfibre towel (M)
Light, tiny when folded, dries in under an hour. The M size (60 × 80 cm) is the minimum to be comfortable after a shower. A detail that matters: not every refuge provides a towel, so your own is genuinely part of the essentials.
View productAccessories
Opinel No. 5 knife
The backpacker’s minimalist knife: it weighs almost nothing and cuts everything you need in the field — sausage, cheese, bread, small fixes. No bulky multi-tool gadget, just the essential that works. Hard to do simpler and more effective for the weight.
View productSimond MT900 trekking poles
Telescopic and ultra-compact, they stow away easily when the terrain needs your hands. Genuinely useful on the GR20’s long descents where they spare the knees and secure your footing on unstable rock. Once you’ve tasted the help they give over twelve days, you don’t set off without them again.
View productAbout the weights: those marked “≈” come from the manufacturer specs, the others are from my own gear. A few weights are still missing and will be added. Prices are indicative (bought 2025-2026) and vary by model and promotions.
Before you leave
Quick pre-departure checklist
This checklist isn’t gospel. It serves as a final review so you don’t forget any of the important categories of gear.