The Gymboss Interval Timer and Stopwatch is a small, easy-to-use, dual interval timer. This multi-use timer has many versatile functions that make it beneficial to virtually any type of exercise program and helps keep your workout on track. With a Gymboss timer, a minute rest really means a minute rest; a 45 minute workout lasts 45 minutes! Maximize your training to increase: Anaerobic endurance, Muscle strength/size, Cardio endurance, Increased VO2max, and Fat loss. Gymboss - Train Hard, Train Smart.