Is the mind-muscle connection real or the most successfully marketed placebo in fitness

The mind-muscle connection gets credited for everything from better hypertrophy to injury prevention. But how much of it is actually neurological reality versus a feeling that makes training seem more effective.

There is legitimate research showing that internal focus – consciously thinking about the target muscle contracting – produces greater EMG activation in that muscle compared to external focus on moving the weight. The effect is real and measurable.

But the supplement industry has attached "mind-muscle connection" to every nootropic ingredient as a selling point, often at doses where the neurological effect is negligible.

The concept is real. The supplement claims around it are mostly not. Which ingredients have you actually noticed making a genuine difference here?