Correlation vs. Causation

Posted On Nov 4, 2013 By Tim Arndt, Resistance Training Specialist

causation to healthy weight loss

A few years ago a friend of mine started using a weight loss shake and lost about 50 pounds in just four months. As you might imagine, he was thrilled with his results and preached about the superiority of this shake to all his friends, claiming it was the cause of his weight loss.

Many years back another friend of mine wanted to increase his vertical leap for basketball. He had heard about these new shoes with a raised platform on the front part of the sole. The shoe company claimed they would increase his vertical jump drastically. They worked. My friend's vertical did in fact increase significantly after about six weeks of use.

Were the shake and the shoe the cause of the dramatic results or is it just a coincidence? There is certainly a correlation here, but in order to find if they were the actual cause, we need to take a closer look at each of these cases.

My friend who used the shakes had never given much effort into limiting the amount of food he ingested every day. It wasn't until his doctor finally told him that he needed to lose some weight that he decided to do something about it. He had another friend selling weight loss shakes and decided to give it a try. For the first time in his life, he was conscious of what he put in his mouth. At the same time, since he was eating healthier, he figured he should start exercising too.

By being conscious of what he was ingesting he was eating far fewer calories than he normally did. And by adding exercise he increased the amount of calories he burned on a daily basis. The end result being that he, for the first time in many years, had created a consistent caloric deficit. Research has shown many times over that a consistent caloric deficit is rule No. 1 when it comes to weight loss, and when you're in a caloric deficit, you will lose weight, no matter where the calories come from.

woman tying shoes My other friend who utilized the "performance enhancing shoes" had never consistently strength trained, particularly with his calves. His only consistent form of exercise up to that point was playing basketball. The shoes were the first time his calf muscles were faced with an extra challenge on a consistent basis making them stronger and more powerful. However, as with any "newbie" exerciser, just about anything is going to have a positive transfer.

It wasn't the magic potion that caused my friend to lose weight. He lost weight because he controlled his caloric intake and exercised to create a caloric deficit. He could have used any diet program or just simply ate a standard calorie-restricted diet and received the same results. Likewise, it wasn't the magic shoes that caused the increase in my other friend's vertical. His vertical increased because his calf muscles became more powerful by adapting to the new stress posed on them. He could've just as easily started doing plyometric exercises and gotten the same result.

It's important to realize that correlation does not equal causation. In the examples above there were correlations between using certain products and weight loss and enhanced jump performance. But the "causes" were simply caloric deficit and an increase in power of the calf muscles. In essence, it is YOU that causes the result, not the performance enhancing shoe or magic potion.

I'll leave you with a quote from my friend Tim Schultz, strength and conditioning specialist, that wraps this up beautifully …

"Don't always think that your results come from the specific exercise or equipment you're using. Especially in individuals who are new to exercise, I want you to be proud of your ability to be consistent and stop giving all the credit to the other side of things."