Rock hard muscle: bodybuilders say it takes hours in the gym, nutritionists say it takes the perfect diet, and Popeye says it doesn’t take much more than spinach.
So, what does it really take to build muscle?
Muscle building requires understanding and practicing two basic concepts: eating clean and exercising correctly. These two concepts go hand-in-hand to give you ultimate muscle-building potential.
It’s called the “eat clean, train mean” philosophy.
The first step to eating clean and training mean is supplying your body with nutrients for muscle growth. Protein is packed with muscle-building amino acids; naturally, you’ll want to make protein an important part of your diet.
How Much Protein?
The recommended daily allowance is about 0.4 grams per pound of body weight. But, if you want to build muscle, you’ll need about 1 gram protein per pound of body weight. If you weigh 200 pounds, that’s about 200 grams of protein. 
What Are the Best Protein Sources?
The most popular protein source for bodybuilders is whey protein. It has a high biological value (meaning much of its nutrients can be directly used by the body) and contains many BCAAs (branched chain amino acids), amino acids crucial to muscle building. Bodybuilders also appreciate casein protein, which breaks down slowly and provides a more continuous amino acid release. Soy, milk, and eggs also are preferred protein sources. 
But, you don’t have to be limited to drinking proteins. Make sure you eat enough, too. You’ll want to choose protein sources that will help you bulk up, including red meat, fish, and eggs.  If you want to maintain lean muscle mass (build muscle while cutting fat) then focus on lean protein sources such as chicken and fish.
Correctly Timing Protein Intake
Despite popular debate in bodybuilding forums, protein can be taken at any time throughout the day and still provide amazing benefits. However, most people like to eat protein or drink a protein shake about 30 minutes before and/or after a workout to provide muscles with a quick source of amino acids for muscle growth and recovery. 
About half your calories should come from carbs, so they are certainly important. To maintain energy and health, focus mainly on whole grains, fruits, and vegetables.
Making sure you have a healthy dose of carbs before a weight training session is beneficial. That’s because carbohydrate stores in muscles are a quick energy source and lead to better performance ability—and better muscle building. But, your body usually carries adequate carb storage, so you might not need carbs right before your workout if you’ve had some earlier. 
Immediately after your workout, you’ll want a high glycemic carb source. Then you can get the carbs to your muscle cells as quickly as possible to promote muscle recovery. These carb sources could include a combination of dextrose and maltodextrin: dextrose is more quickly metabolized than maltodextrin, but maltodextrin carries less potential for fat gain. Another popular post-workout carb source is waxy maize, a fast-absorbing corn starch derivative. 
As long as you’re taking in the proper nutritional sources through your diet, supplements also can be a big help when it comes to muscle building.
Creatine is an amino acid compound stored in muscle tissue. One study shows creatine given to football players for 28 days significantly improved fat free mass, isotonic lifting volume, and sprint performance. 
However, taking creatine can be a tricky business because people prefer different dosing regimens. Some people recommend an initial loading phase of 20 grams of creatine per day for five days, or 9 grams per day for six days, followed by a maintenance dose of 2 or more grams per day. Other people simply take around 3 grams per day for twenty-eight days. 
Creatine is considered safe, but some users experience nausea, diarrhea, or muscle cramping. Don’t over-do it on creatine and make sure your body tolerates it well. Also, drink plenty of water while taking creatine to avoid dehydration. 
Many pre- and post-workout supplements contain important amino acids that support muscle growth. One of these is beta-alanine, which increases the amount of the dipeptide carnosine in muscles. This allows the muscle to perform for a longer time without getting fatigued. 
Beta-alanine might cause skin tingling and could interact with medications for treating heart problems and erectile dysfunction, so know your medical history before taking beta-alanine.  You’ll want to take between 2.3 grams and 6.4 grams per day to improve performance. 
Arginine is a useful amino acid in supplements as it is converted into nitric oxide, which widens blood vessels for improved blood flow. This improves nutrient flow to muscles. Better yet, arginine stimulates release of growth hormone, which supports muscle building. 
Arginine might cause abdominal pain, bloating, diarrhea, low blood pressure, or other side effects. Between 5 and 9 grams of arginine typically are used in supplements. 
 “Protein 101: How Much Do You Need & Best Sources of Protein.” Available from: http://stronglifts.com/protein-daily-needs-myths-best-sources-protein/
 Matt Weik. “What Type of Protein Is Best for You?” Available from: http://www.bodybuilding.com/fun/protein-types-best-for-you.htm
 Adina Steiman. “The Truth About Protein.” Available from: http://www.menshealth.com/mhlists/guide-to-protein/protein-after-workout.php
 Ben Greenfield. “Should You Eat Carbohydrates Before Exercise?” Available from: http://www.quickanddirtytips.com/health-fitness/exercise/should-you-eat-carbohydrates-exercise
 Jim Brewster. “Post-Workout Carbs.” Available from: http://www.bodybuilding.com/fun/post_workout_carbs.htm
 Richard B. Kreider et al. “Effects of creatine supplementation on body composition, strength, and sprint performance.” Medicine & Science in Sports & Exercise. 1998; 30 (1): 73-82. Available from: http://chua2.fiu.edu/faculty/kalmand/HUN6248/ppp/MSSE%20Efx%20of%20creatine%20on%20body%20comp%20strength%20and%20sprint%20perform%20CLASSIC%20Kreider%20-Almada%201998.pdf
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 “Beta-alanine.” Available from: http://www.webmd.com/vitamins-and-supplements/beta-alanine-uses-and-risks
 “Beta-Alanine: Science Meets Real-World Results.” Available from: http://www.bodybuilding.com/fun/beta_alanine.htm
 “Arginine.” Available from: http://www.webmd.com/vitamins-supplements/ingredientmono-875-arginine.aspx?activeIngredientId=875&activeIngredientName=arginine&source=1
 Kanaley JA. “Growth hormone, arginine and exercise.” Curr Opin Clin Nutr Metab Care. 2008; 11 (1): 50-4. Available from: http://www.ncbi.nlm.nih.gov/pubmed/18090659