You're a guy who likes to lift weights, build bigger muscles, and exercise till your shirts are soaked. Congrats: You're on the path to a better physique.

But here's the thing that lots of dudes typically forget: If you haven’t made sleep a priority, you're doing your body—and physique—a huge disservice. Restful, restorative sleep is so crucial for making sure your muscles and other bodily systems have the time and resources to rebuild, clean out waste, and, well, just rest.

And it goes beyond muscle: A lack of proper sleep can increase your likelihood of obesity, according to a new study from the University of Leeds in the U.K.

When researchers scoured data on more than 1,500 British adults enrolled in the National Diet and Nutrition Survey, they discovered that people who slept an average of six hours a night typically had waistlines measuring a little over 1" more than people who got nine hours of sleep.

Less sleep was also linked to lower levels of HDL (aka "good") cholesterol, which helps to clean the blood of LDL (“bad”) cholesterol, and may be a sign of increased heart disease risk. "Because we found that adults who reported sleeping less than their peers were more likely to be overweight or obese, our findings highlight the importance of getting enough sleep,” said Laura Hardie, Ph.D., a reader in molecular epidemiology at the University of Leeds. "How much sleep we need differs between people, but the current consensus is that seven to nine hours is best for most adults."