What are the differences between rash guards and compression shirts?

Rash guards and compression shirts look similar, but they’re not quite the same. Rash guards protect against abrasion and UV exposure during water activities, while compression shirts compress muscles and wick sweat during workouts.

In a pinch, you can work out or go to the beach in a rash guard or a compression shirt, but you’ll be more comfortable and protected if you wear the right garment. Explore the differences between rash guards and swim shirts, learn when to wear each, and enjoy all-day comfort.

SwimZip sells UPF 50+ swimwear for men, women, and children of all ages.

Compression shirt vs rash guards at a glance

Rash guard and compression shirt fabrics

Rash guards use polyester-spandex blends (typically 82% polyester or nylon, 18% spandex) treated with chlorine-resistant coatings and UV inhibitors. A moderate amount of spandex maintains elasticity despite repeated exposure to pool chemicals and saltwater. 

Compression shirts use varied fabric blends for sweat management, such as polyester-elastane or nylon-spandex. These fabrics wick moisture away from skin during intense workouts.

Rash guard and compression shirt construction

Rash guard and compression shirt durability

A quality rash guard maintains its shape and sun protection through hundreds of hours in chlorinated pools or ocean water. 

The specialized coatings on rash guards that resist chemical degradation don't exist in compression shirt fabrics, so compression shirts break down quickly when exposed to chlorine. They lose elasticity and develop thin spots within weeks of regular pool use. 

🏊 SwimZip's men's rash guards and women's rash guards use marine-grade materials that maintain their protective properties season after season.

Rash guard vs compression shirt for UV protection

Clothes get UV protection from two sources: mechanical and chemical. Mechanical protection comes from tight weaves and thick fabrics that block UV radiation. Chemical UV protection can be sprayed or bathed onto clothing to produce a barrier. Ultraviolet protection factor (UPF) measures the amount of UV radiation a garment reflects. When shopping for outdoor performance apparel, you want UPF 50+, which blocks 98% of UV rays.

You also want a UPF that comes from mechanical protection more than chemical. Chemically derived UPF can wash out of clothing through prolonged water exposure and machine washing.

The UPF rating and source of protection of rash guards and compression shirts vary by brand, but you can generally rely more on rash guards than compression shirts for sun protection. 

Rash guards are thicker, which means the bulk of their UPF rating comes from weave tightness and material density. Many rash guards are chemically sprayed for extra protection, but an old rash guard will still provide decent protection.

Compression shirts are thin, and when worn, the material stretches. This elastic weave allows significant UV penetration, so most UPF 50+ compression shirts are chemically treated to block UV rays, meaning consecutive machine washing or significant pool or ocean time will degrade the protection.

👶 Keep young, sensitive skin safe during all-day water play with kids' rash guards with UPF 50+ protection in every style.

Compression shirts vs rash guards for sports

Rash guards for surfing and board sports

Board wax, sand abrasion, and constant exposure to water and UV damage compression shirts within a few weeks. Rash guards withstand the friction of paddling and maintain their integrity despite hours of saltwater immersion. Rash guards also provide thermal protection, so they keep people warmer in water than compression shirts.

Rash guards for swimming and water aerobics

Pool swimmers who wear compression shirts report fabric breakdown within weeks. The material thins out and loses elasticity due to chlorine, and the shirts start to stretch and drag in the water. Rash guards handle daily pool training for months or years without degradation. 

Compression shirts for gym and running

Compression shirts increase upper-body blood flow, which helps with recovery between gym sets. They also have thin, sweat-wicking fabric that is comfortable for heavy workouts or hot weather.

You can wear a rash guard for running or gym work, but the thicker, more restrictive fabric might get in your way or feel uncomfortable.

MMA and ju-jitsu

Combat sports athletes call their compression shirts "rash guards" or "compression rash guards," even though these garments lack the water-specific features of true rash guards.

Rash guards for combat sports prevent mat burns and skin-to-skin friction during grappling. The reinforced stitching withstands the constant pulling and stretching of submission attempts and intense rolling sessions.

You can wear a regular compression shirt for combat sports, but the thinner fabric tears more easily during ground work. Compression shirts also tend to ride up during inverted positions and may not provide adequate coverage for no-gi training requirements at many gyms.

Choose a priority for mixed training

When your training spans multiple environments, prioritize based on your primary activity. For truly mixed training environments, rash guards offer the most versatility:

• CrossFit beach workouts: Protection during beach runs, ocean swims, and sand-based exercises
• Obstacle races: Coverage for water obstacles, mud crawls, and rope climbs
• Outdoor bootcamps: Transition seamlessly from swimming to calisthenics to running
• Surf conditioning: Paddle training, beach sprints, and core work in one session

The rule is simple: if water is involved at any point in your workout, a rash guard provides better performance than a compression shirt.

🏃 SwimZip's zipper rash guards transition seamlessly from beach runs to ocean swims.

Sun protective rash guards from SwimZip

Every SwimZip rash guard carries the Skin Cancer Foundation Seal of Recommendation. Our fabrics maintain their protective properties through hundreds of hours in saltwater or chlorinated pools for all-day comfort in and out of the water.

🎯 Shop our family matching swimsuits to protect everyone with coordinated style.

Rash guards vs compression shirts FAQ

Why are rash guards more expensive than compression shirts?

Rash guards cost more due to specialized fabrics, chemical-resistant treatments, UPF certification testing, and marine-grade construction. The chlorine-resistant coatings and UV inhibitors alone add significant manufacturing costs. This investment pays off through extended garment life and reliable protection.

Can I wear a rash guard to the gym?

Yes, rash guards work for gym activities, though they may be less comfortable for gym workouts than compression shirts. The fabric of a compression shirt is typically lighter, so you won’t feel unnecessarily restricted during indoor workouts.

How do I know if my compression shirt has UV protection?

Most brands that offer UV protection prominently advertise their UPF ratings on product pages and tags. Look for specific UPF numbers (usually UPF 30, 40, or 50+) rather than vague claims about "sun protection." 

Choose brands that carry independent certifications like the Skin Cancer Foundation Seal of Recommendation, which verifies protection claims through third-party testing.

Are there hybrid garments that work for both activities?

Hybrids are uncommon because the design requirements conflict. Rash guards need thicker, less elastic fabric to provide mechanical UV protection, thermal insulation, and abrasion resistance. Compression shirts require thin, tight-fitting material to properly support muscles and wick sweat during intense training.

A true rash guard's denser weave and water-resistant construction makes it more restrictive than ideal for land-based workouts. Meanwhile, a proper compression shirt's thin, stretchy fabric can't provide the UV blocking, durability, and protection that water sports demand.

Further reading

What are rash guards made of?

Best rash guards

What is a rash guard?

Does UPF wash out of clothing?

Rash guard vs swim shirt