When it comes to muscle growth, we often hear that patience is key. However, if you’re not seeing noticeable size increases month after month, it may be time to rev up your approach and try something new.

In order to build muscle, you need to consistently stress the muscles with appropriate volumes and intensity. This includes training the right exercises, using a proper technique and ensuring you’re eating enough protein and calories to support it all. This can take some trial and error, but if you stick with it, you should be able to see significant gains in both your strength and size after months—even years—of consistent training.

To stimulate muscle growth, you need to work your muscles to the point of fatigue, which typically happens when your muscles feel so incredibly sore that they want to give up. The best way to do this is through high-rep, low-weight exercises like squats, bench presses and dumbbell rows.

For these types of movements, it’s important to use a slow and controlled tempo—three seconds to lift, one-second pause, three seconds to lower, repeat. This allows you to move the weight without getting too pumped, which is essential for maintaining form and preventing injury.

Having a good technique will help you lift heavier weight, which is another key factor in building muscle. “When you start lifting more weight, the muscles have to adapt to that load and respond by growing stronger,” says professional athlete, gymnastic coach, personal trainer and creator of PHIIT Strength Kari Pearce.

Your body’s ability to gain muscle will also depend on your genetic makeup and age. Some people have a harder time gaining muscle than others, and the amount of lean mass you can build will naturally decrease with age (yeah, it sounds backward, but that’s the case). In addition, as you get more seasoned in your training, your body will adapt to the volume and intensity of your workouts.

If you have a hard time putting on muscle, you will need to focus on gaining calories, which means eating until you’re uncomfortably full on a regular basis and adding in some higher-calorie foods like nuts, avocados and fatty meats. You will also need to increase the number of weight-training sessions you do each week and train the muscles that are giving you trouble on a regular basis.

Finally, it’s a good idea to add in some exercises that are less familiar to your body, which can help to stimulate new muscle growth and challenge your muscles in new ways. This can be done by adding in some more bodyweight exercises or introducing some other multi-joint movements that work different muscles. You should also consider changing your routine completely every four to six weeks to keep the stimulus fresh.