TRIPHASIC TRAINING – CONCENTRIC LOADING The last phase of the Triphasic Training model used to develop power and speed in athletes is the concentric development or the shortening phase of muscle contractions. In this phase, we focus on moving the bar as fast as possible. It's important to note that intent is the key factor here, actual bar speed is less important than the athlete actively pushing as fast as they can go. An example of this is shown here with a Barbell Bench Press. Note the intent