TNF calls The North Face Endeavor ThermoBall™ Jacket a "pre- and-post workout" garment, designed to keep the chill of before and early morning workout or after you've finished and worked up a good sweat. Super efficient PrimaLoft® ThermoBall™ insulation offers incredible warmth for weight, and continues to insulate effectively when it's wet. Try this one before and after your next aerobic endeavor.