Hypertrophy – Getting Bigger
First lets understand what Hypetrophy is – Muscle hypertrophy involves an increase in size of skeletal muscle through a growth in size of its component cells. Two factors contribute to hypertrophy: sarcoplasmic hypertrophy, which focuses more on increased muscle glycogen storage; and myofibrillar hypertrophy, which focuses more on increased myofibril size
Or put another way – A range of stimuli (namely exercise of one form or another – weight training, bodyweight training) can increase the volume of muscle cells. These changes occur as an adaptive and often a direct response to training (weights or bodyweight) that serves to increase the bodies ability to generate force or resist fatigue in anaerobic conditions.
Muscle Hypertrophy – Understanding Muscle Growth – Getting Bigger
Hypertrophy and hyperplasia
To properly understand muscle hypertrophy it helps if you first learn some basic human physiology. Hypertrophy basically means cells growing in size, this is different from ‘hyperplasia’, which means cells growing in number.
Muscles are made up of permanent cells called ‘muscle fibers’. As adults we cannot produce new muscles fibers and when their gone –their gone for good. Whilst we can’t produce new muscles cells, we can however change the size of the cells we’ve got. Therefore when you train your muscles and they get bigger, you are not actually growing new muscles cells (hyperplasia), instead each individual muscle cell grows in size (hypertrophy) to help your body cope with increases in muscle loading.
The Explanation is Here
What part of the muscle gets bigger?
A common misconception in the gym is that in order for your muscles to grow you need to tear your muscles such that they grow back stronger. This is incorrect. When you tear a muscle, the muscle cell dies and is replaced with scar tissue, not muscle. Therefore your goal should never be to tear your muscles.
If you look at the diagram below, without getting too technical, basic anatomy shows us that each muscle is made up of muscle fibers (also known as muscle cells). The muscle fibers are then made up of myofibrils and then myofibrils are made up of 2 proteins called actin and myosin (not shown in the diagram).
The size of the muscle fibers in an untrained muscle can vary considerably in diameter. Strength training stimulates the smaller muscle fibers to grow such that they meet the size of the larger ones. This muscle hypertrophy is caused by an increase in the number and size of myofibrils per muscle cell, increased total protein (especially myosin), and increased amounts of connective tissue (tendons and ligaments).
Increases in muscle size (seen in the mirror and measured by tape) can also be a result of increasing capillary (blood vessel) density and through increasing blood flow to the muscle. This increase in capillary density is stimulated by the increased demand for oxygen and blood flow to the muscle during training. This is one of the many ways in which you get fitter, as you train and the demand for oxygen and fuel increases in your muscles your body adapts by increasing capillaries to the region such that next time you can deliver blood more efficiently and better deal with the stimulus.
In summary muscles get bigger as a result of storing more protein within muscle fibers and through increasing the amount of blood vessels and connective tissue. This helps to explain why protein is an important nutrient in your diet when you are trying to build muscle.
If Adult cells can not grow what happens
Given that when you become an adult muscles cells can’t grow in number (hyperplasia), only in size this helps to explain a number of phenomenon.
1.It helps to explain why if we prescribed a group of people the same exercise program, as a group they will all finish in different shapes and sizes. Some people only seem to look at weights and they bulk up like they have been doing it for years, where as others struggle to get bigger even after years of hard training. Essentially what I’m trying to say is that genetics does play a role in determining how many muscles cells you have.
One of the many reasons that some people bulk up more than other is the number of fast twitch muscle fibers they have which is largely genetically determined. Fast twitch muscle fibers are recruited during strength and speed activities and therefore people with a higher percentage of fast twitch muscle fibers will generally find it easy to build muscle size.
2.What you don’t use you lose. When you perform muscle hypertrophy training, muscles generally grow in size to compensate for the need of increased loading, however when you stop training your muscles over time start to shrink. Why? Because as muscles cells get bigger they require more food energy ( higher levels of proteins) to sustain them (even at rest), therefore when you’re not training enough, they start to shrink back down to help your body become more efficient it the way it burns energy. Remember this when you stop training you need to stop eating at the higher level or you get fat.
3.The last thing to consider is the effects of aging. Because your body can’t grow new muscle cells, this also helps to explain why as you get older you tend to lose muscle mass. After the age of 30, you lose approximately 3% of your muscle mass each decade thereafter. The best way to slow down this process is to remain a regular exerciser throughout your entire life which helps to preserve and maintain the integrity of your muscle cells. As a general rule you don’t stop moving because you get old, you get old because you stop moving!
When is the best time to do muscle hypertrophy training?
For athletes muscle hypertrophy training is usually best prescribed early in the off season. There are of course a few variations depending on your chosen field of sport, but for most people this is the ideal time to bulk up as you get good recovery time and other training commitments are limited. Lets face it running distances for pre season training does not allow you to benefit form Hypertrophy training.
This also helps to explain why you will often hear sports commentators say “give him/her another off season.” They are usually referring to the hypertrophy training that is prescribed in the off season to help athletes bulk up and build muscle.
Again depending on your chosen field of sport your training focus usually then changes to strength and power in the preseason, and then functional, speed and agility training during competition. For rugby the ability to remain strong is paramount so players must continue to develop both strength and power throughout the season on a least 2 days a week, one day for each.
Design a Muscle Hypertrophy Training Program
To design your own muscle hypertrophy training program you first need to understand a few basic concepts. First, we explain the theory and then we’ll show you how to design your own hypertrophy program.
When designing a muscle hypertrophy training program there are a few basic things to consider. Unlike strength training, the goal is not to lift the heaviest weight you can. Instead the focus is on ensuring that you adequately fatigue the appropriate muscle and muscle fibers.
Two key phrases here to consider are ‘appropriate muscle’ and ‘adequately fatigue’.
Appropriate muscle refers to the specific muscle that you are trying to target. For example if you want to get a bigger a chest, you need to adequately fatigue your chest muscle fibers.
It sounds simple but so many people get it wrong. If you were to perform chest exercises like bench press but you fatigue more in the shoulders and triceps than you are unlikely to stimulate the chest enough to get the desired result. Essentially you have to be hitting the right muscle (or muscle group) during muscle hypertrophy training for you to maximise your muscle growth returns.
My single biggest tip ever for hypertrophy training is to identify which muscle (or muscle group) you are trying to target and emphasis the activation of that muscle throughout the exercise. You are much better off to reduce the weight a little and ensure you’re using good technique to adequately fatigue the right muscle as opposed to just lifting heavy and recruiting other synergist muscles to help perform the lift. Using synergist (assisting) muscles to help perform a lift is better reserved for strength and sport specific training.
It is generally accepted across the research that higher training volumes are associated with increases in muscle size, however in regards to hypertrophy training, remember it’s not about how much weight you can lift, it’s about getting enough muscle fiber fatigue.
One important factor that distinguishes hypertrophy training programs from other forms of training is the shortened recovery time between sets. If you are trying to build muscle (hypertrophy) your goal is to have a rest period of less than 90 seconds between sets to ensure that the muscle group does not have enough time for full recovery before you start the next set.
Remembering that your aim is to adequately fatigue a muscle with the aim of stimulating hypertrophy. Research suggests you apply the following training principles to design your program.
One method that allows athletes to maximise the benefits of hypertrophy training is the use of split programs. A split program may seem to violate the recommended guidelines for recovery, but grouping exercises that train a portion of the body (eg upper body) or certain muscle areas (eg chest, shoulders and triceps) gives the trained athlete an opportunity to adequately recover between similar training sessions.
Some example of split routines are shown on our weight training programs pages to help demonstrate how you can increase your weekly training volume whilst maximising muscle recovery time and muscle growth. As a general rule athletes new to the gym are best to use a 2 day split program, as you become more advanced you can progress to 3 or 4 day split routine depending on your training goals.
Do not walk into the strength training facility and expect to get into hypertrophy training immediately – It pays to be prepared and preparation for the heavy programs takes at least 4 weeks of pre training – so get prepared to training, and do so without damaging yourself.