In Malcolm Gladwell’s most recent book, David and Goliath, he dissects our commonly-held beliefs about advantages and disadvantages. The books centers around these two questions: Are what we usually perceive as advantages really advantages? And are what we see as disadvantages really disadvantages? This is one of the reasons why I love Gladwell’s writing; he challenges our thinking and changes the way we look at things. One of the concepts he uses to support his argument about advantages and disadvantages is the inverted-U curve.
Gladwell uses the example of elementary and middle school class size to illustrate the theory of the inverted-U curve. Basically, if there are too many kids in a class, the learning environment is compromised, and their academic achievement will suffer. That much is not surprising. But, what is surprising, and almost counterintuitive, is that if there are too few students in a class, academic achievement will suffer as well.
Take a look at the graph above. As you can see, as class size decreases, academic achievement increases…to a point. If class size continues decreasing past that point, academic achievement will be negatively affected. Lots of research and anecdotal evidence supports this idea. In fact, the perfect number of students per class seems to be somewhere around 18. Deviate too far above or below this number, and you run the risk of hurting the academic performance of your students.
What the inverted-U curve theory essentially proposes is that there is an optimal level, or “sweet spot” for many things. While this theory may not apply to everything, it certainly carries a lot of merit. Naturally, after I read about it in David and Goliath, I thought about how it applied to the world of strength and conditioning. Let’s look at a few simple examples.
Take mobility. I think most of us would agree that not having enough mobility in a certain area of the body isn’t good, and that if mobility in that area isn’t increased, injury risk goes up. However, if too much mobility is added, without the stability to control that new range of motion, that is not good, and injury risk goes up, too. Too much mobility isn’t a good thing.
Think about strength. Is it necessary for a professional football player to have a 1,000 pound squat? Not necessarily. You could argue that if they don’t have the ability to translate that strength into sport-specific and position-specific demands on the field, it could decrease their performance. Also, the inherent risk for injury increases as the weight on the bar increases. On the flipside, if a professional football player could only squat 135 pounds, we would probably agree that his performance on the field may suffer and his injury risk may be increased because he isn’t strong enough. Having high levels of strength isn’t always good, just as not having enough strength isn’t good, either.
How about physical stress? In order to make progress towards your fitness goals, you need to apply a certain amount of stress to your body. If too much stress is applied, you run the risk of overtraining; you won’t make progress, and even worse, you will drift farther away from your goals. If too little stress is applied, you still won’t make any progress, as the body is not being forced to adapt to anything. Beyond even just physical stress, there are also certain levels of general stress that are necessary for a happy and productive life. Again, too much is bad, and too little is also bad.
The inverted-U curve tells us that the answer to many things is “somewhere in the middle.” That may seem a bit vague, and rightfully so, because that answer is highly individualistic. How much mobility should you have? That is going to depend on many factors, and the answer will be different for everybody. How strong should you be? Again, it depends. How frequently and intensely should you train to achieve your goals? That, too, depends on the individual, as everybody responds differently to a physical stressor or stimulus.
You can think of the three examples I’ve provided as continuums: one for mobility, one for strength, and one for stress. Pick one of them and think about where you might fall on that continuum. Everyone will be at a different spot, and may need to eventually end up at a different spot depending on the definition of optimal performance and well-being. What we can say, and what the inverted-U curve has shown, is that it is not always beneficial to be at the extremes of a given spectrum. Many of you have probably heard the phrase, “More isn’t always better.” That’s very true, but less isn’t always better, either.
The inverted-U curve theory is certainly prevalent in our world, and can be applied in several areas of our lives, including training, nutrition, and supplementation. Take some time to examine some of the “spectrums” that are important to you and see where you stand. The key to your health, goals, or success may mean being somewhere in the middle.