Building Muscles...
A Look at Muscles, Muscle Growth
and Progressive Overload

Building muscles isn't rocket science but you won't just happen upon big muscles by walking into a gym without a basic understanding of muscle and what causes it to grow. Understanding the goal of weight lifting and how and why it inspires muscle growth will be paramount to your success.

On this page, without making you yawn (hopefully), you'll find a brief and non-technical description of muscles, muscle growth and the basic principle behind which building muscle success will occur - You must force your muscles to grow.

If you're interested in a more technical description of the process by which weight lifting can encourage muscle growth, check out the beginning of Dr. Franco-Obregón's Muscle Building and Creatine article.

Muscles

Muscles are composed of three basic types of fibers.

• Slow Twitch Fibers
• Fast Twitch Fibers (A)
• Fast Twitch Fibers (B)

Slow twitch fibers are those used primarily in endurance activities such as distance running. Weight training with high repetitions of relatively light weights will stimulate and develop these muscle fibers. Training these fibers will not, however, result in significant gains in muscle mass (think of the world-class distance runners you've seen - typically very thin).

World Class Runners On the left is Maurice Greene, a sprinter, and on the the right is Robert Cheruiyot, a marathon runner. Greene shows thick muscular legs due to the training and development of fast twitch muscle fibers while Cheruiyot shows razor thin legs despite extensive endurance (slow twitch fiber) training. If you want big visible muscle, you have to train your fast twitch muscle fibers.

Fast twitch fibers (A) are capable of a greater force but tire more easily than slow twitch fibers. Fast twitch fibers (B) are capable of the greatest force output but also have the least endurance. Fast twitch fibers are those used in explosive activities such as sprinting or power lifting. Weight training with heavy weights will develop these muscle fibers and potentially produce significant gains in muscle mass (think of the huge legs you see on world-class sprinters).

To build muscle and gain weight fast you must focus your training on stimulating the growth of your fast twitch fibers. This means training for strength, not endurance - training with heavy weights and low reps, not light weights and high reps.

Genetics determines the proportion of slow twitch fibers to fast twitch fibers a person's muscles contain. Those with a higher percentage of fast twitch fibers will gain muscle mass more readily. Hardgainers typically have higher percentages of slow twitch fibers and therefore experience a tougher time with building muscles.

Progressive Overload

Muscle growth occurs as a response to stress put on the muscle. When unusual stress is placed on a muscle, the trauma causes small tears in the fibers and connective tissue of the muscle. With sufficient rest and nutrition, the body will repair these tears and add strength and, therefore, size to the muscle fibers in order to be better able to handle such stress in the future. This is called hypertrophy.

Stressing the muscles, resting, then increasing the stress level placed on the muscles and the repetition of this process (progressive overload) is the basic philosophy behind weight training designed for building muscles. The gradual increase in the poundage of weights one lifts will create the need for the body to make the muscles bigger and stronger.

Essentially, what you are trying to accomplish with weight training is to trigger the body's survival mechanism. The increased weight loads are interpreted as a threat to its survival. The genetically programmed response will be to increase muscle mass in order to better be able to handle such threats in the future.

Force Your Muscles to Grow

You cannot gain weight fast by asking your muscles to grow. They won't respond to hints or suggestions. Muscles will grow only when they are forced to grow.

Your body will naturally resist building muscles. Extra muscle will require extra energy and as you know from the diet pages, your body is concerned about energy supplies. The amount of muscle you have now is the amount your body has determined you need. It makes this determination based on genetics, diet and the demands placed on it by your life.

You can't change your genetics but you can increase your diet (supply the body with what it needs to put on and sustain new muscle) and through weight training you can change the demands you place on your muscles.

In other words, you have to make your body believe that it needs more muscle, that it needs to get to work on building muscles when it has the chance (while you're resting). You make the body believe this through your training (progressive overload). Then, through your diet, you must prove to it that you can consistently provide the materials it needs to build and sustain this muscle.

The body is not easily convinced of anything. You must be consistent. It is when you put together a program that accounts for all of the above that big muscle gains start occurring.

Should you train with free weights or machines to stimulate muscle growth? When trying to gain mass, free weights provide the best choice. Exercises utilizing free weights stimulate the maximum amount of muscle fibers and develop accessory muscles which support muscle growth.

Check out this article, Free Weights vs. Machines, to learn more about how building muscles is influenced by the the gym equipment you choose to spend the bulk of your time on.

Related Articles

All The Weight Lifting Articles

	Weight Training Programs To Build Muscle Summarizes all the important parts to designing a weight training program to gain muscle mass.
	Bodybuilding Tips Checklist A checklist of 21 bodybuilding tips to check your program against.
	Sample Bodybuilding Routines 10 sample routines, from pre-program routines to single set routines to more advanced routines.
	How Much Muscle Can You Gain? How much and how fast you can realistically expect to put on quality muscle weight.
	Modeling Your Way To Major Muscle Gain Easily the best but most often ignored approach to successful self-improvement.
	Weight Training Terminology The terms and lingo of the weight training world defined as used on this site.