Have you ever had a trainer tell you to "keep your knees aligned with your toes" or to "squeeze your shoulder blades together"? These are examples of "internal cues." Internal cues refer to things inside our body that cue a certain exercise.

But if your trainer says things like "push the floor away as you squat" or "picture a glass of water on your back" as you do bird-dog, those are called external cues. External cues refer to things outside the body, such as the wall, floor, or imaginary objects.

I'm currently enrolled in a Pilates teacher certification course where they've trained us to use external cues as much as possible. Research has shown that external cues are more effective than internal cues when it comes to teaching motor skills. As someone who comes from the Bharatanatyam dance world, where my teacher only uses internal cues, it felt strange to switch to external cues. I've heard phrases like "point your toes" or "raise your elbows" countless times, but I have no trouble understanding and executing these internal cues. I almost felt like I was forcing it when I tried to avoid using body parts when cueing an exercise.

Although I agreed with the research that external cues can be very effective, I disagreed with the notion that internal cues are not effective. From my own experience, I know that internal cues can be just as effective. In fact, there are many times when I prefer the trainer to simply tell me what to do with my body instead of using external objects to guide me. For example, just telling me to keep my shoulders down is more effective than saying "imagine there is a dumbbell on each shoulder" or something similar.

As it turns out, science has proven itself wrong. New research has been published which shows that the previous research was biased in its reporting, and that external cues are not always better than internal cues.

"Evidence has ostensibly been accumulating over the past two decades suggesting that an external focus of attention is superior to an internal focus for the performance and learning of motor skills. Seven previous meta-studies have all reported evidence of external focus superiority—the most comprehensive of which concluded the benefits apply to motor skill (a) retention, (b) transfer, and (c) performance; results in (d) reduced electromyographic activity during performance, and that (e) more distal external foci are superior to proximal external foci for performance. Here, we reanalyzed these data using robust Bayesian meta-analysis methods that included several plausible models of publication bias. We found moderate to strong evidence of publication bias for all five analyses. Further, we found clear evidence of heterogeneity in each analysis, suggesting the impact of attentional focus depends on yet unknown contextual factors. Our results contradict the existing consensus that an external focus is always more effective than an internal focus. Instead, focus of attention appears to have a variety of effects that we cannot account for, and on average those effects are small to nil. These results parallel previous meta-science suggesting publication bias has obfuscated the motor learning literature."

This new research confirms what I've always believed – that the type of cue that works best depends on the person, their learning style, experience level, and more. It's hard to make a blanket statement that external cues are always better than internal cues.

If we always rely solely on science, it can turn our world upside down. We need to use common sense and real-world experience to come to our own conclusions about what's true for our own bodies.

Science is never perfect. It's always evolving, and humans are prone to error and biases, which we don't like to admit. You can almost always find research that supports your personal beliefs. But what's more important than a single study is considering many different experiments (like meta-analyses and systemic reviews) and using critical thinking based on your own experience to decide what you want to believe. And if there's new evidence that suggests your beliefs are wrong, be open to modifying them.

That being said, I want to hear from you! What cues have you found particularly helpful during exercise? And on the flip side, what cues have you found to be confusing or unhelpful? Don't be shy, I'm all ears!