In order to perform better as an athlete you not only have to be strong but you must be fast as well. Being able to move weight and move it fast is known as force. This comes from Newton’s second law; Force = mass x acceleration. Force can only be produced if it is stored or absorbed by the body because you cannot produce what you cannot absorb.
This applies to any dynamic movement made by the human body and this is where we get the triphasic method founded by Cal Dietz at the University of Minnesota. This method is designed to load the eccentric (lowering) and isometric (pause) parts of the movement to increase the force output in the concentric (raising) portion. At TPC we use this method on our core movements; the squat and the trap bar deadlift.
The triphasic method has three phases:
The eccentric part of the movement is the loading portion. In this phase the eccentric part of the movement is slowed down in order to allow not only more time under tension, but that time increases the amount of force that is absorbed. The slow deceleration stresses the muscles and tendons which then loads the muscle for the concentric part of the movement.
We also use this with our athletes to emphasize proper technique. Due to the slowed eccentric they are forced to stay tight and in good position. For squats we have our athletes stop on pins at their proper squat depth to ensure that they are getting low enough and to get them familiar with how deep they need to squat. So, for squats it is a five second descent, briefly pause on pins, and drive up. During the trap bar deadlift the athletes drive up and descend for five seconds. The first week we use sets of five and then sets of three on the second week to increase the load.
In the isometric phase there is a pause between the eccentric and concentric parts of the movement. This phase is where the athletes have to stop the force load from the eccentric portion and transfer that force into the concentric action. The eccentric and isometric phases also decrease the rate for injury due to the ability of the athlete to decelerate and stop forces to utilize them for force output.
During this phase we have our athletes pause on their squats and deadlifts. The athletes have now performed two weeks of eccentrics to pins. At this point we take the pins out in order to hit depth and also stop the force on their own. For pause timing, we stick anywhere from one to three seconds and then the athletes drive through the concentric action. Once again, the first week of isometric is five repetitions and the second is at three.
After two weeks of eccentric load and two weeks of isometric load, it is now time to put it all together. The concentric phase focuses on the force output after four weeks of learning to absorb more force through the eccentric and isometric loading. It is two weeks of doing the full movement at full speed to load at a higher velocity, transfer power quickly, and explode through the concentric action.
During these last two weeks our athletes work to a heavy set of three the first week and then work to a heavy single the second week in order to test the increase of force output from the previous four weeks and also how it has improved their technique and ability to hit proper depth.
The triphasic method has been shown great improvements in our athletes’ technique and force output not only in our strength training but also in our acceleration and change of direction work during our running portion of our youth sessions. They are learning to absorb, redirect, and produce higher levels of force from loading eccentric and isometric movements which will transfer to their performance on the field and keep them in play.
Authored by TPC Coach Boston Jacobs