Summer’s end is almost here, and for most, that means beating Autumn’s chill with a long vacation or grilling. But the job of building serious muscle doesn’t wait for the man on vacation. You’ve got to lift big and eat big to make it happen.

Luckily for you, Labor day is also synonymous with the great American burger, and the recipes we’ve got here show a daring disregard for the conventional.

Each of these delicious burgers is packed with enough protein and nutrients guaranteed to fill up your belly while helping you fill out your frame.

Not all meat is created equal. Check out the macronutrient values for all the meats used in these recipes (plus a few others so you can consider substitutions).