When you’re starting out, it’s best to start with lower weights so you can focus on good form. But once you’ve gotten your form down, it’s best to lift the heaviest weights you can lift while still keeping good form. Don’t sacrifice form for heavy weights — that is ineffective. But heavy weights, with good form, can give you better results in a shorter amount of time. Heavy weights are not just for those who want to bulk up — that’s a common misconception.