'Get your base layer right when you pull on the Under Armour Heatgear Armour 9" Compression Shorts. Made with sweat-wicking fabric and stretchy material, these shorts keep you comfortable and dry. The super-light HeatGear fabric delivers superior coverage so you can focus on what matters the most. Under Armour Heatgear Armour 9"" Compression Shorts features: Long training sessions, pickup runs, and layered game-day fits feel better when your base layer stays cool, supported, and out of the way. The Under Armour Heatgear Armour 9" Compression Shorts deliver a locked-in feel with lightweight HeatGear fabric, breathable mesh zones, and a streamlined length that works well under shorts or on its own. Size & Fit Guidance For the best fit, we recommend starting with your usual size if you want a true compression feel. Some reviewers who prefer a little more room found sizing up worked better, while most say the 9-inch length stays in place well without riding up. Best For Ideal for running, training, team sports, and everyday base-layer wear when you want breathable support and convenient storage. Styling & Versatility The streamlined silhouette is easy to wear under gym shorts, uniforms, or other training gear, and many reviewers also like it for all-day comfort beyond workouts. The longer inseam and right-side pocket make it a versatile pick for everything from track practice to daily wear. Break-In & Durability Most reviewers say these shorts feel comfortable right away with little to no break-in needed. Across repeated workouts, the supportive stretch, stay-put waistband, and durable build continue to stand out."