Choosing the Right Base layer for Every Activity

January 31, 2025 | icebreaker

What Are Base layers and Why Do They Matter?

Base layers are the foundation of any outdoor outfit. Acting as your first layer of defense against the elements, they regulate body temperature, manage moisture, and keep you comfortable. From hiking, skiing, or running, having the right base layer makes a difference for your adventure.

Unlike casual clothing, base layers are built for performance. Your base layer is your first line of defense against the elements. Choosing the right one can mean the difference between cutting your activity short and enjoying the day to its fullest.

What Material Should a Base layer Be Made Of?

The material of your base layer determines its performance. Synthetic options like polyester or nylon are common, but they often struggle with odor control and durability. Merino wool, by contrast, stands out for its natural versatility:

• Temperature Regulation: Keeps you warm in the cold and cool in the heat. Thermoregulating fabrics help maintain comfort no matter the weather.

• Moisture Management: Moves sweat away from the skin to keep you dry.

• Odor Resistance: Naturally resists bacteria, meaning you can wear it for days without washing.

• Sustainable: A renewable, biodegradable material perfect for eco-conscious adventurers.

Synthetic alternatives might dry faster, but they can trap odors and don’t provide the same natural comfort or environmental benefits as merino wool.

Should Base layers Be Tight?

The fit of your base layer directly impacts its performance. A snug fit is crucial because it ensures the fabric stays in contact with your skin, allowing it to efficiently trap warmth and manage sweat. For activities like skiing and cycling, a tight yet flexible base layer improves mobility while reducing bulk under outer layers.

However, comfort is equally important. A too-tight base layer can restrict movement or cause irritation, so aim for a second-skin feel that moves with you. icebreaker designs its base layers with stretch and softness, making them ideal for all-day wear during active pursuits.

Finding the Perfect Base layer for Your Activity

Hiking Base Layers

Lightweight or midweight merino thermal wool base layers are ideal for hiking. They provide breathable comfort and odor resistance, so you can stay fresh, even on multi-day treks.

Practical Tip: On multi-day hikes, odor-resistant merino wool lets you pack less. One reliable base layer can last for days, keeping your load light and your journey comfortable.

Skiing Base Layers & Thermal Ski Base Layers

For freezing conditions, opt for midweight or heavyweight base layers with a GSM of 200+. These provide warmth and breathability, keeping you comfortable from the slopes to the chairlift.

Practical Tip: Look for base layers with added stretch to ensure freedom of movement while skiing. Flatlock seams and tag-free designs also prevent chafing when worn under multiple layers.

Cycling Base Layers

Lightweight base layers are best for cycling, offering temperature regulation and moisture management. icebreaker’s designs fit seamlessly under jerseys, ensuring performance without added bulk.

Practical Tip: A lightweight merino base layer with a GSM of 75-175 can double as a standalone top for cool-weather rides, reducing the need for additional clothing and making transitions seamless.

Snowboarding Base Layers

Snowboarders need midweight base layers for warmth and freedom of movement. Merino wool ensures comfort on the slopes, with the flexibility to tackle any trick.

Practical Tip: Snowboarding often involves sitting on snow while strapping in. Choose a longer base layer to prevent drafts and keep your lower back covered.

Running Base Layers

For running, lightweight merino wool base layers are perfect. They wick moisture, regulate temperature, and prevent odors, making them an ideal choice for every season.

Practical Tip: Pair your merino wool base layer with a wind-resistant outer layer for the ultimate cold-weather running setup.

Types of icebreaker Base layers

1. Lightweight Base layers

Designed for high-output activities in mild conditions, these are perfect for running, cycling, or warm-weather hiking. They provide breathability and moisture management without adding bulk.

• ZoneKnit™ 125 Base layers

• Everyday 175 Base layers

2. Midweight Base layers

The most versatile option, midweight base layers are suitable for cool to cold weather. Ideal for skiing, snowboarding, and multi-day hiking trips, they balance warmth and breathability.

• Oasis 200 Base layers

• Sonebula 200 Base layers

• ZoneKnit™ 200 Base layers

3. Heavyweight Base layers

Reserved for the coldest conditions, heavyweight merino wool base layers deliver unparalleled warmth. These are perfect for low-intensity activities or extremely cold environments.

• 260 Tech Base layers

• 260 Vertex Base layers

• ZoneKnit™ 260 Base layers

• ZoneKnit™ 260 Seamless Base layers

• MerinoFine™ 300 Base layers

“The brand is extremely comfortable and easy to layer. Pieces that I believe are made to perform in many outdoor settings. You may have noticed that I sound like a broken record as I continually repeat how much I loved the breathability, lightness, and fit of Icebreaker Base Layers. Those are definitely among my favorite things about these base layers and why they will be coming on many more adventures with me.” - (FatmanLittleTrail, 2024)

How Many Days Can You Wear a Merino Wool Base Layer?

Thanks to merino wool’s odor resistance, you can wear a base layer for several days without washing. Many adventurers report wearing the same icebreaker base layer for up to a week on backpacking or skiing trips.

Choosing Base layers by Activity FAQs

Q: How tight should base layers fit?

A: Base layers should fit snugly to ensure effective moisture management and temperature regulation, but they shouldn’t feel restrictive or uncomfortable.

Q: What is the best non-synthetic base layer?

A: Merino wool is widely regarded as the best non-synthetic base layer material for its natural warmth, breathability, and odor resistance.

Q: How many days can you wear a merino wool base layer?

A: You can wear a merino wool base layer for several days without washing, thanks to its natural odor resistance. Many customers report wearing theirs for up to a week during extended trips.

Why Choose icebreaker?

At icebreaker, we’re passionate about crafting sustainably sourced, high-performance clothing for every outdoor activity. Whether you’re hiking, cycling, skiing, or snowboarding, our lightweight, midweight, and heavyweight merino wool base layers ensure comfort and functionality.