Tag Archives: hypertrophy

How to increase muscle mass effectively

One of the most important reasons for many men to train is to increase their muscle mass and look more athletic. To achieve this goal many different training methods have been tried and much research has been done to determine what works and what is less effective or even counter productive. This article will give you best tips science can give you on how to increase muscle mass effectively.

Compound versus isolation exercises

Compound versus isolation exercises: what are the benefits and drawbacks?

Resistance exercise is an excellent way to increase muscle strength and size. In addition, it is often used to improve sports performance. An ongoing debate among fitness professionals, coaches and fitness enthusiasts is about which sort of exercises are most effective, compound or isolation exercises.

Exercise order: strength or cardio first?

Many people wonder about exercise order.Strength or cardio first? Which part of fitness training, cardio or strength training, should be performed first. Both alternatives have advantages and disadvantages so it is hard to give a clear answer but the advantages and disadvantages of each method are outlined below.

The influence of alcohol on training results

The influence of alcohol on training resultsThe influence of alcohol on training results

Although many people often train hard in their gym to lose weight, burn fat or build muscle mass and even use supplements many keep drinking alcoholic drinks. It is widely known that alcoholic drinks have a large negative impact on coordinated movement and reaction time, which is very apparent in driving. But how does regular alcohol consumption influence training results?

Hormonal Effects

The consumption of alcohol after strength training causes concentrations of the stress hormone cortisol to remain elevated longer than usual after training. This causes a longer period of muscle tissue breakdown and the body will take longer to recover from training. In addition, the concentration of free testosterone in men increases compared with not drinking any alcohol after training. This seems a positive effect, however the increase in free testosterone is not caused by an increased production, but by a reduced uptake by the muscles, which negates strength training effects.

Weight Loss and Burning Fat

Alcohol is seen by the body as a sort of poison that needs to be removed as quickly as possible. This process has priority over other metabolic processes in the body. This decreases or stops fat metabolism altogether for as long as there is alcohol in the body. Even a small amount of alcohol can decrease fat metabolism with more than 70%. In addition, the breakdown of muscle tissue as a result of increased cortisol levels, decreases resting metabolism in the long run. Both decreasing fat metabolism as a lower resting metabolism make it harder to lose weight and burn fat.

Hypertrophy and muscle strength

Because alcohol has a negative influence on the uptake of the muscle size increasing hormone testosterone, the muscles will grow less when alcohol is consumed after a resistance training workout than when one remains sober. Protein generation within the muscles decreases greatly and the increased cortisol levels will break down more muscle tissue than usual. In essence, alcohol hinders muscle recovery after training because the body needs to focus on removing the alcohol rather than letting the body adapt to training. For the same reason muscle strength does not increase as much in the long run when drinking alcohol.


Drinking alcohol affects training results greatly whatever your goal is. Burning fat, losing weight in a healthy manner become more difficult, increasing muscle mass is inhibited, muscle breakdown is increased and recovery after training is delayed. Even small amounts of alcohol can cause a decrease in fat metabolism or stop it completely. People who have difficulty losing weight or increasing muscle mass are advised to reduce their alcohol consumption or stop altogether.


-Baechle, T.R., Earle, W.R. (2008). Bioenergetics of Exercise and Training. Essentials of Strength Training and Conditioning. Third Edition. USA. Human Kinetics.

-Kraemer, W.J. et al. (2008). The Endocrinology of Resistance Exercise and Training. Essentials of Sports Nutrition and Supplements. Human Kinetics USA.

-Parr, E.B., Camera, D.M., Areta, J.L., et al. Alcohol ingestion impairs maximal post-exercise rates of myofibrillar protein synthesis following a single bout of concurrent training. PLoS One 2014, 9, 2.

-Suter, P.M., Schutz, Y., Jequier, E. The Effect of Ethanol on Fat Storage in Healthy Subjects. The New England Journal of Medicine 1992, 326, 15, 983-987.

Rest Between Sets during Strength Training

The amount of rest between sets during resistance training is very important because it has a very large impact on the results of your training. When shorter rest periods are used, the training will result in adaptations directed at improving muscle endurance, whereas longer rest periods allow for higher training loads and therefore effective improvement of muscle strength and 1RM.

Local muscle endurance can be very important for athletes who participate in martial arts, and strength training is necessary to improve performance during power lifting events. The amount of rest is essentially determined by the goal of the training. The most used rest periods are between 30-90 seconds, and are a compromise between training for muscle endurance, strength and hypertrophy.

Longer rest periods, from 1,5 minute to 5 minutes allow higher training loads which increases strength. When very short rest periods are used, sometimes shorter than 10 seconds, muscular endurance improves and more growth hormone is produced.

What is Occlusion training and what is it good for?

What is Occlusion training?

Occlusion Training is a form of strength training in Occlusion trainingwhich the blood flow to and from the active muscles is decreased by a tight tourniquet. The decreased blood flow causes the exercised muscles to exhaust themselves much more quickly which causes a stronger training stimulus to these muscles than without this band. This form of training has been developed by the Japanese Yoshiaki Sato in 1966 and is also known as KAATSU training or Blood Flow Restriction Training.

Advantages and disadvantages

As a result of the decreased blood flow the muscles receive a much stronger training stimulus compared with regular resistance training at the same relative intensity. Even when training at very low intenstity (20% 1RM) can cause strong increases in strength and muscle size in beginners. These results are comparable to the results when training at 70% 1RM. When high training intensities are not possible, Occlusion Training can provide similar training results as regular resistance exercise. Until now however, no studies have been performed which compared Occlusion training directly with regular resistance training.

A large disadvantage of Occlusion Training is that not all muscle groups can be trained using this method. A tourniquet is needed to decrease blood flow, which can only be applied on the arms and legs. This limits the use of Occlusion Training for athletes training for a specific sport, but makes it quite suitable for body builders and fitness athletes seeking to improve their physique.

Another drawback is the possible risks involved with restricting blood flow. The increased pressure in the veins can make them expand greatly and damage the valves within. There is also risk of developing a blood clot which can block a blood vessel and cause a pulmonary embolism. (Sat himself was admitted in a hospital for a pulmonary embolism as a result of Occlusion Training). However a study to the appearance of blood clots during Occlusion Training did not find an increased risk and other studies did not report any significant negative effects. Blood pressure does increase more than during regular resistance training, which makes it unsuitable for patients suffering from high blood pressure or cardiovascular diseases.

For who?

Although not much research has been performed Occlusion Training seems primarily suitable for healthy people seeking to improve the strength and size of their arm and leg muscles. For these pruposes Occlusion Training might be an effective alternative training method. People suffering from cardiovascular disease are advised to perform regular strength training and avoid this form of training.


For hypertrophy: Occlusion Training by performing isolation exercises for the arms (biceps, triceps and lower arm muscles) and legs (quadriceps, hamstrings and calf muscles) at 20-50% of 1RM and a tourniquet that restricts blood flow instead of training at 70-90% 1RM. Train 2-3 times a week and perform 3-4 sets of 60-70 repetitions with 30 seconds of rest in between sets. Make sure blood flow restriction is not maintained too long to minimize risks (15-20 minutes at maximum).

See also:

-Split training or full body workout?


-Sato, Y. The History and future of KAATSU training. International Journal of KAATSU Training Research 2005, 1, 1-5

-Lowery, R.P. et al. Practical blood flow restriction training increases muscle hypertrophy during a periodized resistance training programme. Clinical Physiology and Functional Imaging, 2013 E-pub in press.

-Loenneke, J.P. Low intensity blood flow restriction training: a meta-analysis. European Journal of Applied Physiology, 2012, 112, 1849-1859.

-Fujita, S. et al. Increased muscle volume and strength following six days of low-intensity resistance training with restricted muscle blood flow. International Journal of KAATSU Training Research, 2008, 4, 1-8.

-Loenneke, J.P. et al. Potential safety issues with blood flow restriction training. Scandinavian Journal of Medicine and Science in Sports, 2011, 21, 510-518.

Benefits of strength training

Strength training or resistance exercise,  is a very well Man dumbbellknown form of fitness training. Strength training is characterized by performing exercises for short amounts of time at moderate to high external resistances resulting in localized fatigue and possibly muscle failure. Strength training is mostly done by lifting free weights, performing exercises on special machines or by bodyweight exercises such as pushups.


Resistance training has always been associated with fitness training and is essential for bodybuilding. It has many benefits for those that are willing to put in the effort, so here are the advantages of strength training.

  1. It increases maximal strength:

One of the most obvious effects of strength training is that increases muscle strength. Aside from professional strength athletes such as weightlifters, this is a very important effect for elderly as well. A certain amount of strength is necessary to perform everyday tasks. When people are hindered during activities such as walking, cycling or walking a flight of stairs, they tend to avoid these activities. If this pattern is not broken, muscle strength decreases even further, hampering these activities even more. Proper strength training prevents or slows the decrease of muscle strength effectively.

  1. It increases muscle size:

One of the most important reasons many men go the gym is to increase the size of their muscles and look more athletic. One of the adaptations that are necessary to increase strength is to increase the size of the muscle. This effect is very pronounced in men, but far more subtle in women.

  1. It helps weight loss and prevents weight regain:

Weight loss is achieved by burning more calories than are taken in. Muscle mass is active tissue and requires a constant supply of energy even in rest. When muscle mass increases, energy expenditure in rest increases along with it, making it easier to burn fat and improve body composition. And when active, larger amounts of energy can be used than with less muscle mass. Adaptation and recovery following a strength training session increase resting metabolism, helping in weight loss. Lastly, strength training prevents the loss of muscle mass during weight loss, which often happens while dieting. It therefore also prevents the well known yo-yo effect.

  1. It rejuvenates the body:

Resistance exercise stimulates the production of several hormones that help maintain and repair the body’s cells. There is even some research indicating that it helps protect our DNA as we age, effectively delaying the physical aging process.

  1. It decreases risk on metabolic disorders and diseases:

Because resistance exercise increases the amount of active tissue, metabolism is increased and improved. The body needs to optimize carbohydrate metabolism to adapt to the training. This helps in preventing metabolic syndrome, obesity and diabetes mellitus type 2 or can help decrease or reverse their symptoms.

  1. It decreases osteoporosis:

Bone tissue, like muscle tissue, is constantly remodeled. As we age, quality and density of our bones often decreases as a result of increasing inactivity. Resistance exercise stresses the bones, and will slow down or even reverse the development of osteoporosis. Because of the higher training intensity and greater loads placed on the bones it can be even more effective than aerobic exercise in this respect.

See also:

-Advantages of cardio training


Strength training makes women large and bulky

Fact or fable: Strength training makes women large and bulky

Strength training is often seen as a training form best suited for men
Strength training for women
that want to increase their muscle mass. Women often want to lose weight and certainly don’t want to look like bodybuilders. But does strength training make women large and bulky?

It is true that strength training also increases muscle mass in women, which can cause an increase in total body weight. However this increase will be rather small, because women produce far less muscle mass increasing hormones than men. Only when women have exceptional genetic potential to build muscle mass and perform large volume high intensity strength training will have large increases in muscle mass.

Women who want to lose weight would do well to regularly perform strength training, despite a possible increase in body weight. Strength training stimulates fat metabolism after training and an increase in muscle mass increases resting metabolism. An increased resting metabolism makes it easier to lose weight because even in rest the body needs more energy than before. Moreover, strength training exercises all muscle groups, which causes all muscles to remain firm and give the body a more athletic look.

Other effects of strength training that can be very important for women:

-Increase in bone density: Bones get stronger through strength training. Especially after the menopause bone density can decrease significantly. Strength training can prevent this to a large extent.

-Rejuvenation of body cells: Strength training stimulates the production of hormones in the body that aid the body’s cells with maintenance and recovery. This causes the cells to function better and age less quickly.

For women it is highly recommended to regularly perform strength training. It has many health benefits, but helps in weight loss and improving body composition as well. The fear of looking like a body builder is not necessary. Women don’t have the necessary hormone production to produce and maintain large amounts of muscle mass. Female bodybuilders do this by using anabolic steroids and other substances that stimulate muscle mass.

Split training or full body workout?

What is Most Effective for Muscle Growth: Split Training or Full Body Workout?

Increasing muscle mass and strength are important training goals for many people. Muscle hypertrophyNot only for cosmetic reasons but for health reasons as well, people seek to increase their muscle mass. A much used method to increase muscle mass more effectively, a process also known as hypertrophy, is using a split training program. In a split training program only a few muscle groups are trained every workout. This allows more exercises per muscle group which increases the training stimulus to the muscle compared with performing just one exercise per muscle group.

Unfortunately there has been little research comparing split training with a comparable full body workout up until now. However the following advantages and disadvantages are theoretically supported.

Advantages Split Training in comparison with Full Body Workout

-A stronger and more complete training stimulus per muscle group. As a result of combining multiple exercises in one training session, a larger part of the muscle is targeted which results in a larger number of muscle fibers that need to adapt.

-It allows for a higher training frequency. When the increase in muscle mass from a Full Body workout performed 3 times a week is not sufficient, it is a bad idea to perform this workout 4 times a week or more. This will not allow the muscle to recuperate and increase its’ size. A split training regimen, if designed properly, even allows daily training. While muscle groups that have been trained in a previous workout are allowed to recover.

Disadvantages compared in comparison with Full Body Workout

-It is less suitable for beginners. The training intensity is often too high for relatively untrained muscles. Moreover, most beginners will have a hard time reaching the necessary training intensity at all, since they still have to learn to activate their muscles to a larger extent. When they can’t reach the necessary training intensity, split training often offers few advantages.

-It requires a higher training frequency to train all muscle groups regularly. Ideally muscles are trained when they are fully recuperated and adapted to the previous training stimulus. For optimal results it is recommended to train every muscle group two times a week. When a split training is performed two times a week, the muscle will have recovered by the time it is trained again, but the training adaptations will probably have disappeared as well.

-Smaller increases in growth hormone and testosterone production. The increase in hormone production is strongly dependent on the amount of muscle mass that is active during training. Since split training targets a few muscle groups each training, the hormonal response on training is smaller. Recent studies have shown that this hormonal response is not a requirement of muscle growth. However, it is likely that growth hormone production has other beneficial effects, such as stimulating fat metabolism. A full body workout is probably more effective in this aspect.


Using a split training regimen has both advantages and disadvantages. Moreover, no studies comparing both split training and full body workouts have been performed. However a split training allows for a higher training frequency and a more complete workout for each muscle group, while other muscle groups are allowed to recover.


-Kraemer, W.J., Ratamess, N.A. Fundamentals of Resistance Training: Progression and Exercise Prescription. Medicine & Science in Sports & Exercise 2004, 36, 4, 674-688.

-Wescott, W.L. How Often Should Clients Perform Strength Training? ACSM’s Certified News 2010, 20, 2, 10-11.

Weight loss: what works and what doesn’t?

Every year, losing weight is the number one New Year’s resolutionWeight loss. And just before the summer, a lot of people try and lose weight or get in shape to look their best at the beach. A lot of different methods are used to achieve this. From diets, training regimens, fat burners, sauna belts and power plates. To help people lose the pounds, we present a list with the most effective and ineffective or even unhealthy methods to lose weight and fat.

The things that work:

  1. Healthy Nutrition

Many people think that they eat healthy, only a few really do. The body needs the right amount of nutrients to function properly and sufficient calories of course. The fact remains that, in order to lose weight, you have to burn more calories than you take in, but it is more important to get the right amount of vitamins, minerals and proteins. This makes sure your body functions optimally and can therefore burn more fat. In addition you tend to lose less to no muscle mass while eating a healthy amount of protein.

  1. A combination of resistance and cardiotraining.

Wheight loss occurs when more energy is used up than taken in. Training increases the amount of calories used, but we also optimise energy systems in our body, and therefore the capacity to burn fat. This last effect even helps us lose weight, while not working out. Additionally, resistance training makes sure no muscle mass is lost during weight loss, therefore preventing the well known yoyo effect.

  1. Exercising regularly and often

Aside from training, regular physical activity such as walking or riding a bicycle, is very important. This will activate the body, increase the amount of calories used and therefore help in losing weight. It will help the body in recovering from a training and reduce stress hormone levels as an added bonus.

  1. Rest and sleep

Although everyone focusses on nutrition and training while losing weight. Resting and especially enough sleep are very important for health and weight loss. When you don’t sleep enough, the body can’t recuperate enough, stress hormone levels will rise and you will lose muscle tissue sooner.

What doesn’t work or is bad for your health?

  1. Diets

Diets are at best a temporary solution to lose weight. When you stop with the diet and eat what you are used to eating, the lost weight comes back often accompanied by a few extra pounds. The worst diets make you lose muscle mass as well, increasing the chances of the yoyo effect.

  1. Long cardio workouts

Although it is not difficult to lose weight by performing a lot of cardio training and endurance improves as well, too much cardio training can increase muscle breakdown. One of the primary reasons is that stress hormones keep building up. A combination with some form of diet often increases this effect. Furthermore cardio training hinders recovery from training for as long as the training takes. It is better to perform high intensity cardio training for shorter periods. This is more effective and the time you save can be spent on recovery.

  1. Fat burners

There are some fat burning substances that are proven to be effective and safe. However the effects are generally small, and could be used in combination with healthy nutrition and training. Green tea extract is a good and safe example. The fat burners that are effective on their own, are potentially dangerous and illegal in most countries. Among these is Ephedra.

  1. Sauna belt

There are several weight loss programs which incorporate a heated belt tied around the waist during training. The heat from the belt, softens up the fat so the body can burn it more easily, or so they claim. No research can back these claims up however. The body determines the location of fat loss, not your clothing. At best the heat from the belt decreases the amount of water around that location for a short time. When someone loses weight using this method, it can be attributed to the training performed while wearing the belt, not the belt itself.

  1. Power Plates

A lot of research has been performed investigating the effects of the power plate in rehabilitation and weight loss. For weight loss, it is just as effective as the sauna belt. It does not add anything. In other words, how much weight and fat you lose depends on how you train with it. On the other hand, if you enjoy training on it, it can’t harm either.


Unfortunately there are no miracle cures. When you want to lose weight you have to work for it. The most effective method is to perform both resistance and cardiovascular exercise, and combine this with healthy nutrition. In addition make sure you walk or cycle regularly an sleep sufficiently.

How long does it take for muscles to start growing?

When a person starts a resistance training program aimed at increasing muscle mass without any previous training experience, it may take some time before results are visible. Despite the rather large increase in strength during the first few weeks, the muscles do not grow very rapidly. How long does it take for muscles to start growing? And how is it possible that the muscles are getting stronger without growing larger?

This can be explained by the nervous system recruiting more muscle fibers during a specific exercise, which could not be activated before. In addition, autogenic inhibition, or antagonistic muscle activity, is lowered which results in an increase in net produced force, without the muscles having to work harder. Moreover, the antagonistic muscles work even less. In other words, the nervous system optimizes the muscular system and it learns how to use the muscles more effectively without any structural adaptations such as hypertrophy, which cost a lot of energy and protein to realize.

During the first two to three months of resistance exercise, this mechanism plays the largest role in increasing muscle strength. Hypertrophy, while present to a small extent, will become more noticeable when most of the potential of the muscles has been reached and the muscular system receives adequate stimulation to warrant further adaptation. This means that exercise intensity must increase continuously so muscles have a reason to grow, when the nervous system cannot realize any further improvements in muscle coordination. After the period in which the nervous system improves muscular coordination, hypertrophy will become more noticeable.


-Heyward, V.H. Designing Resistance Training Programs. In: Advanced Fitness Assessment and Exercise Prescription. 2009. Human Kinetics, Champaign USA.

-Wilmore, J.H., Costill, D.L., Kenney, W.L. Adaptations to Resistance Training. In: Physiology of Sports and Exercise Fourth Edition. 2009. Human Kinetics Champaign USA.

Free Weights vs Machines

Free Weights vs Machines: People often wonder if resistance training with free weights is better than training with machines and why. Both methods have distinct advantages and disadvantages which are discussed in the article below.

Training with machinesFree weight vs. machines

-Training with the aid of machines is often much easier. Machines ‘force’ the person training with them to make a certain movement and

therefore it is easier to train with correct technique.

-Because it is easier to perform an exercise correctly and movement is forced in a certain direction there is less chance of injury.

-Machines are often easier and quicker to set up

-The stabilizing muscles are not activated as much and will hardly be trained, so the limiting factor is more often the larger muscle groups that are targeted by the specific exercise. (ie. the main muscle groups receive a proper training)

Training with free weightsFree weight vs. machines

-Training with free weights, even when performing the same basic movement as with a machine (for example a dumbbell press vs a chest
press) activates the muscles that aid and stabilize the movement to a greater extent. This has important implications for stabilizing ability of certain joints.

-Because there is more variation in movement, strength gains are not as specific as in training with machines, but more general, meaning that strength useful in real life will increase more. In addition, the stabilizing muscles are trained to a greater extent, making free weight training superior in increasing ‘real life’ strength.

-Improvement in proprioception also known as the sense that detects position and movement of the body. Because more attention has to be paid to a correct technique during training, people using weight training are better aware of what their body is doing, which makes it easier to correct bad posture and to train more effectively.

-Because it is harder to perform the exercise correctly, the movement is not forced into a certain direction and more stabilazation is needed there is a higher risk of injury compared with training with machines.



Testosterone is an androgen (male sex hormone) that promotes the development of secondary male characteristics during puberty.  These include characteristics as a deeper voice, facial hair and an increase in muscle mass. Testosterone stimulates, directly (through testosterone receptors on muscle fibers), and indirectly, (through stimulating Growth Hormone production in the pituitary), hypertrophy. The increase in muscle mass caused by testosterone increases muscle strength. However this is not the only reason muscle strength increases. Testosterone can also bind with receptors on neurons (nerve cells), where it influences the production of neurotransmitter and the structure of nerve cells. Testosterone increases strength not only by increasing muscle mass but by improving muscle activation as well.

Testosterone is primarily produced in the testicles in men, and in the ovaries and adrenal glands in women. Men produce 15-20 times more testosterone than women, and the effect of different training protocols is greater on testosterone levels in men as well. In women, testosterone levels are hardly influenced by strength training or other forms of exercise, which partly explains the lower potential in women for increasing muscle mass.

In addition, an artificial form of testosterone (androgenic anabolic steroids) is used to stimulate muscle strength, hypertrophy and contraction speed, to increase performance in sports and athletic events. Most athletic organizations have banned the use of androgenic anabolic steroids and athletes who are caught using them risk suspension. Moreover, the use of androgenic anabolic steroids increases risk of developing cardiovascular disease and several forms of cancer.


– Baechle, T.R., Earle, W.R. (2008). Endocrine Responses to Resistance Exercise. Essentials of Strength Training and Conditioning. Third Edition. USA. Human Kinetics. -Wilmore, J.H., Costill, D.L., Kenney, W.L. (2008). Ergogenic Aids and Sport. Physiology of Sport and Exercise Fourth Edition. USA Human Kinetics.


Superset training is a form of exercise organization in strength training, in which a combination of two exercises are alternated without rest. Many combinations of exercises are possible, but traditionally two antagonistic exercises are combined, which target opposite muscle groups. This way, when performing the second exercise, the muscle groups that were active during the first exercise are allowed a short rest before their second set.

Superset training has several advantages over traditional 3 set per exercise training. Firstly, by combining two exercises without rest, training time is effectively cut in half. Secondly, because the muscles get a shorter rest period, and because they can rest less effectively while other muscles are active during their rest, muscles can not recover as well as during normal training. This results in increased acidification, lactate production and muscle fatigue, which can lead to greater muscle adaptations and muscle growth. Thirdly, due to the same amount of work performed in less time, the body’s work capacity increases and needs more energy during recovery (EPOC), which helps weight loss and improvement in body composition.

Superset training is less suitable for those just starting strength training because training intensity is higher than during regular strength training with rest periods after each set. Superset training is mostly done by combining exercises targeting opposite muscle groups, such as biceps and triceps. However, it is possible to make other combinations as well, such as a standing calf raise and shoulder press (calves and shoulders). As long as muscle groups during one exercise, are not or hardly active during the second exercise, they can effectively be combined into a superset.



myostatin deficient dog

Wendy the myostatin deficient dog

is a cytokine which functions as an antagonist for Insulin-like Growth Factor-1. It is therefore a negative regulator of muscle growth. In other words, it causes the breakdown of muscle tissue. It is an essential substance in maintaining balance in protein synthesis and protein breakdown. This is most obvious in animals that have mutations in their DNA, rendering the myostatin gene less active or even completely shutting it down. These animals have an highly increased muscle mass and look like bodybuilders among their species. This reduces muscle function as well, since myostatin also serves to improve muscle quality. However it also plays a major role in diseases such as muscle dystrophy, where myostatin activity is increased and muscle mass decreases progressively.


Hypertrophy Hypertrophyis the process of growing tissues. In exercise physiology it normally refers to muscle hypertrophy or the increase of muscle mass. Muscle hypertrophy as a result of training is caused by an increase of cross section of themuscle fibers which form the muscle. This increase is caused by an increase in net protein production.

Growth Hormone

Growth hormone is produced in the anterior pituitary gland. The best known function of growth hormone is stimulating cell growth in almost all tissues, hence the name. Growth in children is regulated by growth hormone. In adults it still has many important functions, not the least of which are inducing muscle growth or hypertrophy, stimulating bone mineralization and increasing lipolysis or fat metabolism.