The Physical Stress Theory is a comprehensive approach that has evolved from several pre-existing theories in an attempt to simplify Physical Therapy and create a guide for application. The theory essentially discusses physical stress and its adaptive effect on our biological tissue. The five tissue responses are: atrophy (not enough stress), maintenance (equal amounts of stress), hypertrophy (enough stress), injury (too much stress), and death (excessive stress).

As easily as this theory can be applied to Physical Therapy, it can just as easily be applied to training. Overall, the main goal of training is to stress the body enough to create an adaptive response (positive training effect), but not too much that it crosses the individuals unique threshold and causes injury. I refer to this balance as the “sweet spot.” For me, the most difficult part of training is finding this sweet spot and then staying in between the lines.

Since injury can happen with increased stress over time, it is often difficult to identify what specifically causes it. Many times it a combination of several contributing factors such as (according to the paper below), exercise/movement/alignment, extrinsic factors, psychological factors, and physiological factors. If injury occurs, the goal is then to identify these contributing factors and find ways to modify or reduce stress on the injured tissues.

This is why I believe trainers/ strength and conditioning coaches have a giant responsibility - your clients are essentially putting trust in you to create an individually catered program that finds this sweet spot, keeps them there while still gradually progressing, and be able to modify/adjust accordingly if injury does occur. Sometimes it is not always obvious how or why injury occurs (whether it is from a prescribed exercise or any other factor listed), but you must be willing to analyze all these factors, create a hypothesis, implicate it, see how they respond, and then go from there.

Another way I like to present this idea is finding the right balance between a person’s “inner athlete” and evolution. Evolution sometimes works against us in that our bodies want to conserve energy and avoid change. This, to me, is why it is normal to have a natural resistance to energy expending exercise. Our “inner athletes,” on the other hand, want us to push past any discomfort because that is what we are taught, even when we are perhaps pushing too hard. This is a common issue I see with a lot of current or former athletes and/or type A personalities, but it is your job as a trainer to prevent a person’s inner athlete from taking over. I find that taking a step back and explaining how counterintuitive over-stressing your body is usually does the trick. A great coach once said “it is not how much we can do in the weight room, it’s how little we can do and still get the adaptation we desire (with the lowest cost possible).”

Training is a excellent way to mold and change ourselves into exactly what we want to become, but we need to approach it intelligently and work to find our own “sweet spot.”

Check out the full article at:
https://academic.oup.com/ptj/article/82/4/383/2837004

Stephanie Spoto, CSCS