Bridging the gap between fast fashion and high style, Theory is a highly esteemed New York label. Launched in 1997 by Andrew Rosen, the brand established the label with a simple design philosophy 'that men and women should feel comfortable in modern clothing. Theory is now a holistic lifestyle brand with its wide ranging collections of clean, sleek apparel and accessories. Give casual wardrobes renewed direction with the men's Theory sweats collection. From jersey tracksuit trousers to merino wool sweatshirts, these pieces are versatile enough to wear to the gym and to lounge around at the weekend.