Everyone has a lagging body part that needles at them. Unfortunately, genetics play a big role in your body composition and what parts are difficult to build. But whether it’s skinny calves, flat biceps, or a wide waist, there are things you can do you build up (or trim down) the parts of your physique that bother you. 

While it’s an uphill battle against what nature gave you, you can focus on targeting specific muscle groups to give them a little extra boost. With some time and attention, you can build the all-around physique you’ve always wanted. Here are nine of the most common problematic body parts and our remedies for how to build them up.