Every exercise is designed to hit certain muscles. As a result, if your form is off, those muscles don’t get the proper stress, and you don’t grow stronger.
Take squats, for example: they’re meant to target legs and glutes. But lean too far forward or round your back, and those muscles won’t engage. Ten squats with proper form beat fifty sloppy ones.
And what’s more, such an outcome from bad form affects your motivation, making you struggle to stay fit. The good news is, perfect posture is the first step, and when you’re still stuck, there’s more you can do to help you achieve your fitness goals.