Men's Health editors tested 10 underwear styles and ranked boxer briefs from Mack Weldon and Calvin Klein as top performers. The evaluation focused on fit, comfort, durability, and moisture management across extended wear periods. Mack Weldon's design prioritized breathability and support for all-day activity. Calvin Klein's offering delivered reliable performance at mainstream retail price points. The testing methodology involved real-world conditions rather than laboratory settings, assessing how each style performed during typical daily activities and workouts. Both winners earned praise for waistband stability, which prevents the ride-up problem common in inferior designs. The testers also evaluated fabric quality and stitching longevity after multiple wash cycles. Price differentiation emerged as a key factor. Premium options from boutique brands offered marginal improvements over established alternatives. The analysis separated marketing claims from observed performance. Cotton-blend compositions outperformed synthetic-only materials for temperature regulation. Fit consistency across sizing proved critical. Calvin Klein maintained tighter tolerances in production, while Mack Weldon offered extended sizes for broader populations. Neither product marketed recovery benefits or performance metrics tied to athletic output. The testing avoided endorsing unsubstantiated comfort claims common in apparel marketing.