We Completed the SAS Fan Dance with a 20kg Ruck
What is the Fan Dance?
The World's Oldest Special Forces Test. The Fan Dance is a gruelling 24km route march through the Brecon Beacons, and it is quite simply one of the hardest things you can put your body through in a day. It has been used as an official SAS selection test for decades, arriving at the end of Week 1 of the SAS selection course as a brutally efficient filter of who has the physical and mental make-up to continue.
The route goes up and over Pen Y Fan, the highest peak in South Wales at 886m (2,907ft) and then back again in reverse. What makes it so savage is that you start climbing immediately, there is no warm-up, and the return leg forces you up the notorious Jacob's Ladder after your legs are already spent.
Today the Fan Dance is open to the public through an official race series run by former SAS and SBS soldiers, staged in both summer and winter to mirror the actual selection programme as closely as possible.
Stage by Stage Breakdown
Understanding the route before you arrive is critical. The terrain varies enormously, from open moorland paths to ankle-snapping rocky descents and the weather in the Beacons can change without warning.
The race starts at the iconic old red phone box on the A470 near the Storey Arms outdoor centre. From here the ascent begins immediately with no flat warm-up.
The route climbs steeply up the west-facing slopes, skirting Corn Du before reaching the Pen Y Fan summit at 886m. This is Checkpoint 1. The climb is relentless and sets the tone for everything that follows.
After the summit, you descend the far side via Jacob's Ladder — a steep, rocky staircase-like path that demands serious concentration, especially under load. Tricky footing here; take your time on the rocks.
At the bottom of Jacob's Ladder you hit the Roman Road — a long, undulating off-road vehicle track stretching to the Tal Fechan forest area. This is your best chance to move quickly and bank some time before the return.
Here is where the Fan Dance really earns its reputation. You turn around and face Jacob's Ladder on already-exhausted legs. This is the hardest section of the entire event. Keep your head down and keep moving.
After Jacob's Ladder you re-summit Pen Y Fan (Checkpoint 3) and descend the west slope back to the start. The final downhill is on your own legs. Push hard here and leave nothing behind.
Local knowledge: The Brecon Beacons weather can go from clear to zero-visibility fog in minutes. Even in summer, carry an emergency layer. The temperature at the summit is consistently several degrees colder than at the start point.
What You Need to Carry - Rucking Backpack & Weighted Vest
Choosing the right rucking backpack is one of the most important decisions you will make before the Fan Dance. You are carrying significant weight over technical terrain for several hours, and a poorly fitting pack will destroy your shoulders, hips, and back long before your legs give out.
The official load-bearing category requires a minimum weighted rucksack of 35lbs (approximately 16kg) for men and 25lbs for women, not including your food, water, and mandatory kit. In practice, many competitors finish with a total pack weight closer to 20–22kg once food and water are factored in, which is exactly what we carried.
| Category | Men | Women | Notes |
|---|---|---|---|
| Minimum base weight (rucking backpack) | 35 lbs / 16kg | 25 lbs / 11kg | Verified at start |
| Food & water (est.) | ~2–3kg | ~2–3kg | Minimum 2L water |
| Mandatory safety kit | ~0.5–1kg | ~0.5–1kg | Map, compass, whistle |
| Typical total pack weight | 18–22kg | 13–16kg | Weighed at start |
How We Got On - 5 Hours 30 Minutes
We completed the Fan Dance carrying a 20kg rucking backpack, finishing in 5 hours and 30 minutes. Here is the honest truth: it is hard. The opening climb hits you before your body has had any chance to warm up, and by the time you reach the summit of Pen Y Fan for the first time you already know you are in for a serious day.
The descent via Jacob's Ladder on the outbound leg is technical, loose stone, steep gradients, and the weight of your rucksack constantly threatening to tip you forward. Take your time here. A twisted ankle at this point ends your day.
The return leg up Jacob's Ladder is where the mental battle really begins. Your legs are burning, your shoulders are raw from the pack, and you are staring up at the same steep ground you just descended. This is the moment the Fan Dance sorts people out. Break it into small sections. Focus on the next 20 metres, not the summit.
How to Prepare for the Fan Dance
The Fan Dance rewards specific preparation. General cardio fitness will get you started, but rucking under load on hills is a different kind of suffering that you can only prepare for by doing it.
- Ruck with your race pack - Train with the exact rucking backpack you plan to race in, loaded to race weight. Do not discover fit issues on race day.
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Train on hills, not treadmills - The incline grades on Pen Y Fan cannot be replicated indoors. Get out on hills every week in your build-up phase.
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Use a weighted vest for conditioning - A weighted vest is a brilliant training tool for building load-bearing capacity at lower intensities, ideal for daily walks and gym sessions.
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Train your hip flexors & glutes - Steep climbing under load is dominated by your posterior chain. Prioritise step-ups, Bulgarian split squats, and deadlifts in your strength work.
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Break in your boots - New boots on the Fan Dance is a rookie mistake. You need at least 50–80km of walking in them before race day or blisters will end you early.
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Nail your nutrition strategy - Eat every 45–60 minutes on the move. High-carb, easy-to-digest food. Do not wait until you are hungry, by then you are already behind.
Want help choosing the right rucking backpack or weighted vest for the Fan Dance? Visit our online store for all your rucking gear.
