It's shown in studies that most people don't train hard enough to achieve muscular growth.People tend to underperform with around 30-40% of what it takes to achieve maximum results. Now, this doesn't mean that you should just add weight and go bananaanas, some people will not be able to handle an increase in weight, or volume, because of various complications or injuries.But, if you feel you could have lifted more, or done more reps, there's probably some truth to that #trainharder