Under Armour Men's Mk-1 Shorts - Lightweight, Breathable Performance

Our review of the Under Armour Men's Mk-1 Shorts finds them best for active men who want lightweight, sweat-managing gym or warm-up shorts that move with them. The single biggest reason to buy is the combination of stretchy 4-way knit and fast-drying fabric, which creates a barely-there feel while keeping sweat under control during intense sessions. The shorts are clearly designed for movement and breathability rather than layered support, so they perform excellently for running, training, and post-workout wear.

Key Features

• Stretchy knit fabric: Delivers a super lightweight and comfortable feel so the shorts do not weigh you down during long workouts.
• Moisture-wicking material: Wicks sweat and dries fast to help keep skin drier during high-intensity training sessions.
• 4-way stretch: Moves better in every direction so lunges, sprints, and dynamic drills feel unrestricted.
• Mesh side panels: Add targeted breathability to hot zones to improve airflow and reduce overheating.
• Encased waistband with drawcord: Provides a secure, adjustable fit without digging in while maintaining a smooth exterior.
• Open hand pockets: Offer convenient storage for small essentials while you train or cool down.

Who It's For

The Mk-1 Shorts suit men who train regularly and need a lightweight, breathable short for gym sessions, warm-ups, or casual runs; the 7in inseam hits a balanced length for mobility and coverage. Runners, cross-training athletes, and anyone who prefers a no-fuss short with quick-dry performance will appreciate the fabric and construction.

Those who need built-in compression or a liner for extra support should look elsewhere, since these shorts have no liner. If you require thermal insulation, heavy-duty durability for outdoor work, or substantial storage, a different style would serve better.

Pros & Cons

Pros

• Very lightweight and comfortable fabric that minimizes chafing during prolonged wear.
• Effective moisture management keeps the shorts feeling dry during heavy sweat sessions.
• 4-way stretch and mesh panels improve range of motion and ventilation for active use.
• Encased waistband with internal drawcord ensures a secure, adjustable fit.

Cons

• No built-in liner, so users who prefer added support or compression will need separate base layers.
• Pockets are open hand style only, which limits secure storage for small items during vigorous activity.

Specifications

Our Verdict

The Under Armour Mk-1 Shorts are a strong pick for active men who want a lightweight, breathable short that handles sweat and supports full-range movement. They offer excellent value for gym-goers and runners who do not need a liner or heavy storage, combining fast-drying fabric and 4-way stretch into a comfortable everyday training short.

Frequently Asked Questions

Do these shorts include a built-in liner?
No, the Mk-1 Shorts do not have a liner; wear separate compression shorts if you want added support.

Are the shorts suitable for long-distance running?
Yes, the lightweight fabric, moisture-wicking finish, and 4-way stretch make them suitable for many runners, though lack of a liner may affect some users.

How is the fit at the waist?
The encased elastic waistband with internal drawcord provides an adjustable, secure fit that stays comfortable during dynamic movement.