If you want to grow your muscles but aren't sure where to start - you're already there! And we're here to tell you that gaining muscle mass doesn't have to be as complicated as it might seem. Muscle growth, technically called hypertrophy, really boils down to doing two main to-dos: progressive strength training and eating protein. How long it takes to build muscle varies from person to person, says Liz Applegate, PhD, director TitanRise Official of sports nutrition at University of California, Davis. Genetic differences affect how fast people gain muscle and how big their muscles can ultimately get. To help make the process easier (and as fast as possible!), TitanRise Official we dug through the studies and tapped the brains of researchers, exercise physiologists and sports nutrition experts. The result: We IDed the 13 most important hypertrophy tips and you got this comprehensive guide on how to build muscle. Generally, if you're new to a structured resistance training program, you want to hit each muscle group two to three times per week, says Michaela Devries-Aboud, PhD, assistant professor of kinesiology at the University of Waterloo.

For most people, the easiest way to do this is by focusing on full-body strength-training workouts. As you get more experienced, you may want to move to upper- and lower-body workouts and perhaps eventually to muscle-group splits. That means each workout targets a different muscle group (such as the chest and triceps, back and biceps, shoulders, legs, hips, etc.). Lift a load that you can use for 3 to 4 sets of 8 to 12 reps, according to the American Council on Exercise (ACE). The key here is lifting to fatigue, Devries-Aboud says. That means you're lifting a weight that's heavy enough to make the last 2 reps of each set very difficult to complete. But you can still do them without your form faltering. Don't have heavy enough weights? July 2016 research in the Journal of Applied Physiology suggests that the heaviness of weight you're lifting doesn't matter as long as you lift to "volitional" or "technical" failure. This happens when you can't do any more reps with good form, and is different from "muscular" failure when your muscles literally give out and you drop the weight.

So if you can't reach fatigue at a certain rep and set range, increase the reps and sets (or weights) until you can. If you want your muscles to get bigger, you need to keep challenging them. Once you can move through an exercise with perfect form and still feel like you have gas left in the tank, it's time to up the ante. Devries-Aboud recommends following the 2x2 rule: If you can add 2 reps to the last set of an exercise in two consecutive workouts, it's time to progress your training. Ideally, that means increasing the weight. That helps you get stronger in addition to putting on muscle mass, but you can also increase the number of reps and sets. For upper-body exercises, going up by 2.5 to 5 pounds may be plenty, while you may need more like 5 to 10 pounds (or more) for lower-body exercises.

If you don't have another weight available, you can also make exercises harder by adding a pause or doing them more slowly. Eventually, about every four to six weeks, progress your workouts by changing some of your moves to more advanced versions. For example, instead of doing the dumbbell deadlift, you can try a heavier loaded barbell deadlift. Or, start curling more weight on your arm days. When you eat protein, your body breaks it down into its components, called amino acids. Thee molecules are your muscles' building blocks. So, if you're trying to build bigger muscles, you need to give them a lot more protein to use. The recommended daily allowance (RDA) of protein, or the amount of protein you need to eat each day to meet the average person's nutrient requirements, is 0.8 gram per kilogram of body weight. So, a 150-pound (68-kilogram) adult needs to eat at least 54 grams of protein per day.

There are 2.2 pounds in a kilogram. Exact recommendations vary a bit from study to study, but most experts suggest that, if you're strength training and trying to put on muscle, you eat about 1.6 grams of protein per kilogram of body weight. So that same 150-pound, 68-kilogram person would need about 109 grams of protein a day. Applegate says that when you're starting a strength training program, you may need closer to 2 grams per kilogram of your body weight. A June 2016 Nutrients review found that adults' muscle tissue becomes less responsive to protein over the decades. The best way to combat this is upping your protein intake. If you've ever tried to increase your protein intake, you know it can sometimes be hard to get it all via whole foods. That's where protein powders and shakes come in: They can make it easier and more convenient to reach your protein goals. Whey protein powder is popular (and is often used in ready-to-drink shakes), because it's a good source of the amino acid leucine, which essentially triggers the muscle protein-synthesis process, Applegate says.