The GR20 is one of Europe's most famous and demanding trails. Crossing Corsica from north to south over nearly 180 kilometres, it is renowned for its impressive elevation gain of more than 10,000 metres and its technical sections. If you dream of taking on this challenge, meticulous preparation is essential. Whether you're an experienced hiker or a mountain enthusiast, this guide will help you prepare thoroughly for the GR20, so you can live an unforgettable experience while minimising the risks.
The GR20: a legendary and demanding route
The GR20 is a hiking route that crosses Corsica from north to south in 16 stages. This trail, which takes around 15 days to complete, is known for its technical sections, impressive elevation gains and sometimes harsh conditions. The trail begins in Calenzana, in the north of the island, and ends in Conca, in the south. Although the route becomes more manageable in the south, the northern section is particularly challenging, with steep and technical terrain. This challenge attracts nearly 20,000 hikers each year, but the dropout rate remains high — around 40% — largely due to the difficulty of the early stages.
Choosing the right direction for the GR20
It's important to think carefully about the direction in which you want to tackle the GR20. Although the route can be done in both directions, most hikers opt for the north-to-south direction. However, if you're setting off at the start of the season, it may be wiser to begin from the south to avoid the difficulties caused by snow on the northern heights. From a sporting perspective, starting from the north is often recommended, as it means finishing on the more accessible stages.
What is the best time to go?
The GR20 being a mountain trail, choosing the right time to go is essential. June and the first half of September are generally the best times to complete this hike. Avoid the summer period (July and August) as the heat can be intense, and the trails are often packed with hikers. The heat can also make hydration more difficult and increase the risk of dehydration. Late spring and early autumn offer ideal conditions to enjoy the scenery while avoiding the crowds.
Preparing physically and mentally
The GR20 is a major sporting challenge, and your preparation must be carefully planned. To succeed, you need to be in good physical shape and ready to tackle sometimes very technical climbs and descents. It's essential to train for several months before you set off. To do so, go on hikes in mountainous terrain with a loaded rucksack to simulate GR20 conditions. In addition to endurance, you need to condition your muscles to sustained effort by strengthening your legs, ankles and cardiovascular system through cardio and strength-training sessions.
Preparing your kit for the GR20
Choosing the right gear is crucial to completing the GR20. Here are the essentials to take with you:
- Rucksack: A 40-litre pack is sufficient if you're not fully self-sufficient. It should be lightweight and comfortable, and not exceed 20% of your body weight.
- Clothing: Use the three-layer system to regulate your temperature. Go for technical t-shirts, a fleece and a waterproof jacket. Don't forget to protect yourself from the sun — especially in Corsica, where it can be extremely strong.
- Footwear: Choose stiff shoes with a good grip and thick sole. High-cut hiking boots are ideal for rough terrain. If you prefer lighter trail shoes, make sure they offer good durability, good cushioning and a toe cap.
- Hiking poles: They'll be invaluable for relieving pressure on your joints, especially on climbs and descents.
Planning food and accommodation
The GR20 has refuges along the route, but some are unstaffed and bivouacking outside designated areas is prohibited. You will therefore need to organise your accommodation in advance. If you prefer to sleep in a refuge, it is strongly advised to book ahead, especially during high season, to avoid any unpleasant surprises. Some refuges offer hot meals, but you can also choose to be self-sufficient and carry your own food. In that case, it's essential to plan for light, energy-packed meals such as freeze-dried dishes, and to restock at Vizzavone, the only resupply point on the route.
Tips for completing the GR20
Here are some tips to ensure your GR20 experience is a success:
- Walk in a group: It's always more enjoyable and safer. The mutual support among hikers is a valuable asset when it comes to overcoming difficulties.
- Stay hydrated: Water sources can be scarce in summer, so fill your bottles whenever you get the chance.
- Look after your feet: Massage your feet every evening, tend to your toenails and apply cream to prevent blisters.
- Test your gear: Never set off with equipment you haven't tried before. Do several long outings to test your footwear, your rucksack and your clothing.
- Book your refuges: If you're setting off during peak season, remember to book your overnight stays in mountain refuges in advance.
The GR20 is a sporting challenge, but with the right preparation it remains achievable. Good training, rigorous planning and suitable kit will allow you to make the most of this exceptional adventure. The beauty of the Corsican landscape — wild mountains, dense forests and breathtaking panoramas — will make this an unforgettable experience. Follow these tips to prepare well for the GR20 and enjoy a rewarding, memorable hike.
