When done properly, lifting weights can be a great way to build muscle, burn fat, and shed pounds. When done incorrectly, however, it can be more than just ineffective – it can lead to injury. Whether you’re new to lifting or a seasoned gym-goer, it’s just as important to know what to do as what not to do. The next time you pick up a barbell, keep these common mistakes in mind and do your best to avoid them.

1. Isolating Muscle Groups

If you’re new to the gym, you may be tempted to stick to the machines. The trouble with machines is that they typically isolate one muscle rather than strengthening an entire muscle group. Isolation exercises might provide cosmetic gains but if you want to get stronger, aim to gain functional strength more than just size. The key to functional strength lies in workouts and exercises that utilize multiple muscle groups – using your whole body to put your muscles through their full range of motion.

2. Starting with Too Much Weight

The goal is to get stronger, but you won’t develop strength overnight. The first step is to learn proper form so you can complete exercises safely and effectively. Once you understand the movement and have sound technique, you can gradually add weight to build strength. Starting with too much weight puts you at risk for injury. Consider working with a personal trainer to learn proper form and determine good starting weights.

3. Not Engaging Your Core

Your core is the key to functional strength and it’s the foundation from which you build total-body strength. A strong core stabilizes your spine and supports your muscles in every movement you make, improving stability and reducing your risk for injury. Incorporate core strength exercises (not just abs) into your weightlifting routine and keep your core tight and engaged during every lift.

4. Ignoring Your Diet

When it comes to fitness, diet and exercise go hand in hand. The composition of your diet greatly impacts the results you’ll see from your workout routine. Fuel your body with clean, whole foods and make sure your diet emphasizes lean sources of protein to help you gain and maintain muscle. Whether you want to lose weight or gain muscle, work with a dietitian to help you determine what’s right for your goals.

5. Not Taking Time to Rest

You won’t make any progress if you don’t spend time in the gym, but the time you take off is just as important. Not only do you need to rest your muscles between sets, but you should provide your entire body with enough rest and recovery time in between workouts. Refuel your body with a protein shake after each workout to help jumpstart your recovery and maximize gains.

There will always be a learning curve when you try something new but starting with a strong foundation may help speed up the process. As you get into a rhythm with your new weightlifting routine, take steps to correct the common mistakes listed above. With time, dedication, and proper form, you may finally start to see the results you’ve been waiting for.