therunningbug Fri, Feb 1 2013 11:57 AM Likes20 11 Comments Facebook5 Twitter2 Speed (Interval) Training - Fartlek Training Techniques The Running Bug explains speed (or interval) and fartlek training, what the benefits are and how to do them properly. Follow our step by step guide below. To continue, log in or sign up. It's FREE and only takes a minute! Log in to your account OR Sign up with Facebook JOIN NOW for FREE!