There are 3 types of muscle in the body, cardiac muscle, smooth muscle, and skeletal muscle.  The cardiac muscle control the muscles of the heart, the smooth muscle controls the blood vessels and the intestines.  We are going to talk about the skeletal muscles because those are the muscle responsible for your daily movements, and those are the muscles that gives you that aesthetic look that you want, i.e. that six pack.  There are two types of skeletal muscles, fast twitch muscles and slow twitch muscles.  The fast twitch muscles are used for making power movements, like sprinting, jumping, lifting heavy objects.  The slow twitch muscle are the muscles used for endurance, like running for long distances.  Most people want to have an athletic look, so the type of muscles you would be trying to build are your fast twitch muscles.  Everyone has fast and slow twitch muscles in their body but the percentage varies from person to person.  A person’s genetics determine how much of each type of muscle is in their body. Some people are more naturally inclined to have a athletic look because they genetically have more fast twitch muscles in their body.  But another factor that determines the percentage of each muscle type, is the type of activity that you do on a normal bases.  If you do a lot of athletic activities, like sprinting and jumping, your body will develop more fast twitch muscles, but if you do less athletic stuff like running long distance your body will develop more slow twitch muscles.  You can see this, when you look at the body types of sprinters, or gymnast, versus the body types of long distance runners or long distance swimmers.  The sprinters and gymnast, have much more defined muscles because they have more fast twitch muscles, than the long distance runners and long distance swimmers.  World class power athletes like a sprinter has 60%-90% fast twitch muscles, while world class endurance athletes have 60%-90% slow twitch muscles.

                                                       How Muscle is Built

Muscle is built by resistance training, you can use the resistance of your own body, weights, bands, etc.  The way in which you use the resistance weight is with progressive overload, which means you make the resistance heavier as time goes on. If you are using weights you use heavier weights, for a band, use a stronger band, etc.  The muscle grows by micro-tears happening within the muscles when you are exercising, the muscle then heals itself and becomes bigger and stronger.  Your muscles fibers increase in number and size which makes it bigger, this is called hypertrophy. The micro-tears in the muscles results in the muscle being sore, most soreness last 2 to 3 days. A man’s muscle growth will be greater than a woman’s growth due to the hormone, testosterone.

The Workouts that Build Muscle

There are two main types of workouts that build muscle, there is lifting heavy weights with a few reps, and there is lifting lighter weight with a lot of reps.  Heavy weights is a weight that you can only lift 5 times or less, lighter weights is something that you can lift over 10 times.  If you choose to lift heavy, it builds muscle, and gives you muscle size, if you lift lighter weights with more reps, it gives you more definition.  The recommendation is that you do both to build complete strength.  The best way to lift heavy is to use weights. There are many ways to lift light, you can use light weight, you can use your own body weight, you can use bands, etc. 

Body Parts and Lifting

Some muscle are better suited for lifting heavy weights than others. The bigger the muscle group, the more suited it is for heavy weight lifting.  Your legs, your chest, your back are major muscle group that are more suited for heavy weights.  Smaller muscle groups, like your shoulders, your biceps, cannot lift as heavy and do better with lighter weights and higher reps.  When you do compound lifts you can lift heavier weights.  Compound lifting is when you are using multiple muscle groups at once to lift weights, for example using the chest and tricep muscle group, or the back and bicep muscle group.  When you do compound muscle group you can put on a lot heavier weights, example of these types of exercises are bench press, dumbbell backrows, etc.  When you isolate particular muscles during exercises it is best to use lighter weights.  Isolating muscles mean you are only exercising one muscle group, you are not exercising multiple muscle groups. One muscle group is smaller than multiple muscle groups, so when you are doing isolation exercises you should use light weight and higher reps.  Examples of isolation muscle groups, are the biceps, front shoulders, quadricep, back shoulders, etc.  If you lift too heavy on the isolation muscle groups, you are putting yourself at a high risk of injury.

The Nutrient Required to Build Muscles

Your muscle are made out of protein, so you need to eat protein to rebuild the muscle.  When you are lifting weights, especially when lifting heavy weights, your muscle are tearing therefore your muscles need protein and energy to rebuild the muscle.  Your muscles get the protein from food, such as chicken, beef, eggs, beans, etc.  Your muscles gets the energy from multiple sources, from food like carbs i.e. bread, rice, etc, or from fat that is already stored in your body.  The muscle can also get it’s energy from eating it’s own self, the muscle is made of protein, so as a last resort for energy the muscle can eat itself, turning protein into energy. Many people think that they need to eat extra protein in order to grow muscle but this is not true.  For muscle growth, 2.2 grams of protein per kilogram of your body weight is needed per day, and the average American diet eats more than that.  The problem with eating extra protein, or eating extra food in general when you are trying to gain muscle, is if your muscles do not use the extra protein to build the muscles, then it will turn it into fat. Eating extra protein is necessary if you are a thin person and you do not have enough fat on your body for your muscles to use for energy, so what your body does is eat the protein of your muscles for energy, this makes it impossible for you to gain muscles.  So by eating extra protein, usually in the form of protein supplements, your muscle will have some extra protein left to build up the muscle if it has to eat some of itself for energy.  Another solution to help build muscle if you are too thin, is to eat a lot more carbs, your body will have energy from the carbs to build up your muscles, it will not have to eat itself for energy.   

The Timeline of Building Muscles

You will begin to see noticeable change in your muscle in 4 weeks, but to see significant muscle growth it will take about 3 months.  You can expect to see 1 to 2 pounds of muscle growth per month, and as the months and years go by the muscle growth slows down. You can expect to hit your muscle growth ceiling in 4 to 5 years, but with specialized training you can continue to gain muscle up to 10 years of training. The amount of muscle gain varies from person to person due to their different genetics. A woman will gain half the muscle a man will gain.  Also in order for your body to see significant muscle growth you need to exercise any particular muscle for a minimum of 2 times per week.  You must use the progressive overload to see your muscle growth.

                                           The Timeline for Muscle Lost

Science shows that you will begin to lose a small amount of muscle after 1 week of not working out.  After 1 month of not working out you will see significant decrease in your muscles, athletes lose less muscle mass than non-athletes. The older you are the faster the muscle loss occurs, after the age of 25, you will lose half a pound of muscle every year, if you don’t do any exercise.  There was a study done with 2000 participants and they were grouped by age, 20 years to 30 years, then 60 years to 75 years.  They were put through the same exercise regimen and they took a break for 6 months, the older group loss double the amount of muscle as the younger group. It is easier to regain muscle when you have had experience with gaining muscles, because of muscle memories.  When you starting fresh with exercise, muscle growth happens slower.