This fitness video is an introduction to interval training and Troy Jacobson’s entire SPINeRVALS series. Workout B on developing threshold and speed. This workout 'elevates' the intensity and is designed to boost your anaerobic fitness.  Delivered straight to your PC, TV or iPod, this is a great way to burn calories, reduce body fat and increfase your aerobic fitness. This is a comprehensive training routine that introduces you to benefits of Troy’s interval training programs.