Ultralight clothing for fastpacking: how to dress to go fast, light and without wasting energy.

There is a moment in the mountains when you notice it.
It is not a specific kilometre or a famous hill.
It's that instant when, all of a sudden, everything flows, You climb without overheating, you stop without getting cold, you move forward without hesitating about what to put on or take off.
And at that moment you understand that clothes are not an accessory...
is a tool.

The fastpacking does not forgive excess weight and punishes errors in thermoregulation.
But with the right system, the clothes disappear:
only you, the rhythm and the mountain are left.

Here is the guide used by the fastpackers to move fast with less than 500 g of technical clothing.

What you'll get out of this guide (seriously)

Know EXACTLY what to wear so you don't sweat too much or get cold.
Remove the 70% from the weight that many carry “just in case”.
Change constant stops → constant flow.
Carry only what really works on 1-3 day routes.
Stop guessing what layers you need: use a clear and replicable system.
Make fewer mistakes than most on their first outings.

The ultra-lightweight layering system for fastpacking (simple, proven, efficient).

We are not here to theorise.
This is the exact system that works in heat, cold, wind, humidity and long routes.

1) First layer: where your comfort begins

The aim is not to keep you warm.
The aim is to don't get soaked.

Merino 150 g/m² → regulates temperature and odour.
Technical polyester → maximum breathability for high tempo.

If this layer fails, all other layers fail.

2) Second layer: minimal but strategic

Almost everyone here screws up.
You don't need a jumper “just in case”.
You need a thermal microbuffer for short stops.

Fine fleece 100-150 g → light, warm, quick to manage.
Light thermal in cold → but only when it's time.

Less is more.
Most of the time.

3) The windbreaker: the piece that multiplies your efficiency.

If you could only choose one garment, this would be it.

70-90 g (yes, grams).
It protects you from the wind.
Keeps you warm without overheating.
It allows you to go on and on.

A good windbreaker is the border between flowing... and suffering.

4) Ultra-lightweight waterproof: use it only when it counts

Typical mistake: using it to “wrap up”.
Result: become your own greenhouse.

Search:

2.5L or 3L
10,000-20,000 mm
150-250 g

It is your insurance, not your climbing layer.

❌ Top 5 energy-sapping mistakes (and how to avoid them)

Climbing too warmly → you sweat, you stop, you cool down.
Use the mackintosh as a windbreaker → condensation ensured.
Wear thick layers → they weigh too much, regulate too little.
Do not expect wind on hills → misleading thermal sensation.
The “just in case” adding 300-500 g → useless weight.

Solution: a clear, replicable, lightweight system.

My real kit for 1-3 day routes (less than 500 g)

Merino 150 g
Fine fleece 100-150 g
Windbreaker 80 g
Waterproof 180-220 g
Shorts + light mesh
Buff + cap

Enough.
Efficient.
And tested in real terrain.

⭐ What it's like inside Outsiders

Inside we share real configurations, real questions and real solutions.

No theory.
Just distilled experience.

🔗 Keep building your ultralight system

👉 Fastpacking: the complete guide to getting around lightly
👉 What to eat in fastpacking (without cooking)
👉 How to choose an ultralight backpack
👉 How to plan your first route
👉 Fastpacking on the GR11

Fastpacking Quick Guide (Free)

The guide is designed to give you a start without chaos, without doubts and without buying things you don't need.

It includes:

What to check before leaving
How to choose your first route
Which material matters (and which doesn't)
Typical 90% errors on start-up
How to move lightly without losing safety

It's free... but it's part of something bigger.

The guide is just the beginning, within the trial you also have the checklist, recommended equipment, resources and the challenge modules to get you up to speed quickly.

📥 Download it here (access with the free trial):
👉 https://www.skool.com/outsiders/about