Sierra Designs Borrego Hybrid Jacket

Most breathable insulated jacket
Borrego Hybrid Jacket


Weight 11 oz


Our take Winter temperatures in western New York are unpredictable, but our tester came to trust in one constant: this jacket. On trail runs and cross-country ski tours, she stayed comfortable in the Borrego, no matter if it was 15°F or 50°F. Credit the 60 grams of synthetic PrimaLoft Silver Eco in the torso, combined with sides and sleeves devoid of insulation; the Borrego breathes well enough that she hardly ever felt like taking it off as the weather warmed into shoulder season. “The only time I was cold wearing this was running along the shores of Lake Ontario in 30°F temps and 15-mph winds, but other than that, having max airflow was always welcome,” our tester says. Her only major complaint: After a couple months of (admittedly hard) missions three to five times per week, it picked up a funk—moreso than the other jackets in the test—that wouldn’t completely wash out with tech detergent.

The details A 20-denier ripstop polyester treated with PFC-free DWR over the insulation on the chest keeps snow and light rain at bay, while a four-way-stretch nylon/spandex blend on the hood, sleeves, sides, and shoulders grants some flexibility. The Borrego has two zippered hand pockets (one of which the jacket packs into, slightly larger than a softball), as well as two interior drop pockets.

$175; 11 oz. (m’s L); m’s S-XXL, w’s XS-XL