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The perfect body fat percentage

Der perfekte Körperfettanteil

Here's a quick summary:

  1. There are four things you need to consider when trying to build muscle: Hormones, psychology, health and strength.
  2. Gaining mass when you are already overweight can affect your ability to build muscle, and gaining too much weight can interfere with different exercises.
  3. Endomorphic exercisers should not perform a mass-building phase if they have a body fat percentage of over 15% and they need to build muscle slowly. Ectomorphs need to be more aggressive with their bulking phase and calorie intake.
  4. Use mirrors to assess your progress rather than having your body fat percentage measured

Stay lean while trying to gain mass

How lean should you get before you start a bulking phase? Is there a point at which you are too fat to gain mass? And while we're on the subject, how lean can you stay while still being able to build muscle?

These are big questions. Here are the answers.

4 factors of hypertrophy

Train with weights, eat well, recover and repeat. The "how" of building muscle is no big secret. The questions come with the details.

There are 4 primary factors involved in building muscle: Your hormones, your mental well-being, your physical health and your body structure.

No two individuals are the same and no two bodybuilding programs should be the same. Let's examine the factors and then develop a battle plan for you.

Hormones: Factor #1:

We all have different metabolic and hormonal profiles in addition to different nutritional needs. When we talk about bodybuilding, these differences play a big role in how fast we build muscle and how fat we get in the process.

A genetic ectomorph (a skinny guy with a lean physique) will obviously have different nutritional needs and responses than a genetic endomorph (guys with a chunky physique who build fat easily).

If the endomorph tries to stay as lean as the ectomorph while trying to build muscle, he will waste a lot of time and make no progress.

Hormones such as testosterone, estrogen, cortisol, thyroid hormones and insulin all play very important (and independent) roles in the process of manipulating body development. If we look at each hormone in isolation, we get the following:


Too much

Too little


Rarely a problem

Increase in body fat, decrease in muscle mass


Increase in body fat

Joint problems, health problems, slower muscle gains


Slower metabolism, decrease in muscle mass, increased fat gain

Rarely a problem

Thyroid hormones

Difficulty gaining weight, muscle weakness, fatigue

Slower metabolism, fatigue, increased body fat percentage


Insulin resistance, increase in body fat, increased blood pressure

Type I diabetes

For men based on diet and body fat:

  • High body fat levels: typically correspond with an increase in estrogen levels, insulin levels and cortisol levels.
  • Optimal body fat levels: Barring any abnormalities, this is the range where most people's hormone levels are balanced and optimized.

  • Very low body fat levels: For most, very low body fat levels will result in sub-optimal hormone levels - such as reduced testosterone levels and increased cortisol levels - which will interfere with long-term muscle gains.

Obviously, competitive bodybuilders will get much leaner for their competitions than this, but this is not something they will maintain all year round - especially if they are trying to get more muscular.

And remember that hormones are linked. Change one hormone and you change a number of other hormones at the same time. When something gets out of balance, it can cause a hormonal cascade that results in a variety of problems, which can make it difficult to achieve results.

It can also be difficult to pinpoint the root of the problem due to the ripple effect nature of hormones.

Psychology: Factor #2:

You also need to consider the mental and social aspect of weight gain. If you are an ectomorph who is uncomfortable eating 6000 kcal a day, then your life can be hard. You need to keep things reasonably comfortable if you plan to play this game long term.

Health considerations:Factor #3:

Overdoing it with mass building and getting fat will potentially raise blood pressure, blood sugar, and blood lipid levels (cholesterol and triglycerides).

Make mass gaining your lifestyle and these problems can lead to diabetes, cardiovascular disease, kidney problems and other serious health issues. They will also cause hormonal imbalances that can slow down your gains.

This is a situation where you can only lose. You are out of shape, your health is suffering and you are hindering your bodybuilding goals.

Remember that bodybuilding is more like a marathon than a sprint. The guys with the most longevity have the most success. Ronnie Coleman won his last Mr. Olympia title at the age of 41. Three of the seven winners of the last national championships were over 40.

If you ignore your health by getting too fat, your body may be too broken to run the hypertrophy marathon in the long run.

Strength and leverage ratios: Factor #4:

In general, the bulkier you are, the stronger you are. Increased body weight not only helps from a muscular point of view, but also from a mechanical point of view.

Leverage ratios are more optimal for most exercisers when they are bulkier, and a bulky core will help you with exercises like squats (for stabilization) and bench presses (by reducing range of motion).

One exercise that usually suffers from weight gain is the deadlift. For most exercisers, the leverage ratios on this exercise get worse as they gain weight. A leaner core helps to get into position when deadlifting so that more power can be used from the legs and it becomes easier to get 'behind the bar'.

So we know that getting bulkier generally makes you stronger - and getting stronger is a great way to build muscle - but at what point will the benefits start to diminish?

Obviously, the extra ten pounds you add on bench presses and squats won't mean much if you're upsetting your hormonal balance at the same time - especially when the time comes for you to diet all that flab off again and see what's hiding underneath.

If you continually chase higher weights on the bar and on the scales without taking the mirror and your health into account, then your gains will be very short-lived. Sagging skin is not particularly cool either.

Slimming all year round

While excessive body fat can certainly interfere with optimal muscle gains, I'm also not an advocate of staying in contest shape all year round. If you're afraid of losing your six-pack and gaining some extra weight, then you won't get much further.

A middle ground between the two extremes is best. Build enough weight to allow consistent, realistic gains in strength and muscle mass without compromising your health or disrupting your endocrine system.

But remember that there is no "one size fits all" strategy that is optimal for everyone. Much depends on your natural body type.

A guide for the big, bulky guys (endomorph body type):

Trying to stay too lean will sabotage your gains. Trying to gain too much weight too quickly will also backfire. You will build fat at an astonishing rate.

Endomorphic strength athletes should aim for a weight gain of half a pound to a pound per week to ensure that most of the gains are of a quality nature. Due to fluctuations in glycogen and water, these will not always be linear gains, but try to keep the trend at one pound or less per week.

Heavier individuals (over 115 kilos) can aim for a slightly higher rate of weight gain, where I'm talking about one to one and a half pounds per week.

Warning: If your body fat percentage is over 15%, you need to get this under control before you think about gaining weight. I recommend keeping your body fat percentage between 10 and 15% during the bulking phase.

A good method is to use a bulking phase - averaging about a pound a week - until you reach your upper limit of body fat percentage for your body type and then diet (smartly) for a while until you get back to the lower end of the range.

So build up until you reach a body fat percentage of 15%, then diet down to 10% and repeat.

The guide for skinny guys (ectomorph body type):

If you are an ectomorph, you should use a slightly more aggressive approach. An ectomorph will typically not only need more calories for muscle growth due to their faster metabolism, but will also burn fat faster, so putting on some extra flab shouldn't be a big problem for them.

Ectomorphically inclined strength athletes should aim for faster gains than endomorphically inclined ones - perhaps one to two pounds per week or more, depending on the situation. The truth is that their fast metabolism will usually make this difficult anyway unless they really increase their calorie intake significantly.

As with endomorphically predisposed people, a weight gain of half a pound to a pound is what we will usually see in practice. It's rare to see endomorphically predisposed strength athletes reach a body fat percentage of more than 12%, so their goal should be to use their mass-building phase until they reach a body fat percentage of 12% - at an average weight gain of one pound per week - and then slowly diet down to 8 to 10% body fat.

We hate you - No advice for mesomorphic strength athletes:

Mesomorphically inclined strength athletes are the ones who just have to look at a barbell to grow. And they stay reasonably lean regardless of their diet. If you're reading this article, you're probably not one of these athletes.

Set Point Considerations

The human body has numerous internal thermostat-like control processes that help it maintain a state of homeostasis. It tries to maintain a reasonably "normal" state of body processes and it can be quite difficult to change this so-called set point.

Have you ever noticed that when you finish a diet, your body tries to get back to the weight you started with? It's what your body is used to and it's trying to get back to that state.

One way that might help shift this setpoint is to maintain the new weight for a longer period of time to try to get your body to adopt that weight as its new setpoint.

Shifting your setpoint can take months. So instead of getting your weight up to a certain level and then immediately dieting down again, it might make sense to maintain this new weight for six months or longer. This will help you maintain more of that new muscle mass when you eventually diet again.

Of course, this doesn't mean getting fat and staying fat! It means building muscle, keeping your body fat percentage under control and then maintaining the new weight for a while before slowly getting leaner again.

The competition form

For those who regularly compete in a body sport such as bodybuilding, staying in shape during the off-season is even more important. It takes too much time to lose that excess weight before a competition and you risk losing too much muscle mass in the process.

And too often I see guys go up to 25 kilos over their competition weight because they think they're making massive progress (sure they look massive in a sweatshirt). Then they diet down and compete the next year at the same weight as before.

The bullshit stops when they take off the sweatshirt. If you compete on a regular basis - at least once a year - then monitoring your body fat is a must if you plan to improve year on year and climb the competition ladder.

Assessing your progress

Use mirrors to assess your progress. Sure, body fat percentage is important. But to be honest, it can be expensive and inconvenient to have your body fat percentage measured accurately on a regular basis. So instead of going by specific numbers, I prefer to use the mirror and take photos to assess my progress.

Your lower back and core usually don't lie. They will tell you if you are building up too much fat. Once your love handles reach the point where they hang over the side of your belt, you've gone too far.

A little extra flab is okay, and a lot of what accumulates during the day is water, but you should never reach the point where you can measure a fold of flab more than 2.5 centimeters thick.

And as for your midsection, you should always be able to see at least a rough outline of your abs (no great detail, just the general contours) and always have a visible serratus.

Stress control and sleep

It's easier said than done, but reducing the stress in your life can help you tremendously in your muscle building efforts. A lot of stress increases levels of the hormone cortisol, which limits your muscle gains and promotes fat gain. Try to get plenty of sleep and don't get too worked up about unimportant things.


There is no magic number when it comes to the optimal body fat percentage for building muscle. By using the guidelines from this article, you can develop your personal best method for optimal hypertrophy while staying healthy and fit.

By Shelby Starnes


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