Alpha Progression
Dirty Bulk vs. Lean Bulk - How to succeed in your bulk!

Dirty Bulk vs. Lean Bulk - How to succeed in your bulk!

If you ask different strength athletes in the gym how they design their bulking phase, you will most likely get two answers: Some swear by a so-called dirty bulk, which focuses on a large calorie surplus with quick results.

The other side, on the other hand, rely on the so-called lean bulk, in which a moderate calorie surplus leads to slower results, but with as little fat gained as possible.

But what is the best method to make your bulk as efficient as possible?

  • Putting the dirty bulk and the lean bulk to the test
  • Bulking and hormone balance
  • Muscle growth and fat storage
  • Food choice and calorie surplus

Dirty bulking: Mass = Class?

A dirty bulk is a form of muscle building characterized by a high caloric surplus. This would mean eating significantly above your daily calorie requirement. A surplus of +500 calories or more is not uncommon when it comes to people who want to put on as much mass as possible. In this case the result would be a calorie surplus of 3,500 calories per week.

To best determine your calorie needs, you can use the Alpha Progression Calorie Calculator.

Basically, in this form of bulk, it is worthwhile to track the intake of food in order to constantly achieve the desired surplus.

Some advocates even swear by eating as much as possible without looking at the calories. However, you should be aware that this also gives you less control and you won't be able to track your surplus very well.

When it comes to food choices, you're free to go for "clean" calories or, as the name suggests, eat "dirty." You decide for yourself whether you want to eat large quantities of the classic chicken with rice and broccoli - or prefer to go to the drive-in of a fast food chain.

The number on the scale should go up as quickly as possible. The principle of dirty bulking is to build mass quickly. However, it is not only pure muscle mass. Besides muscle, your body will also put on a lot of fat.

Dirty bulk advantages

You will gain weight fairly quickly. With a high calorie surplus and a focus on strength training, you will notice changes in your body after a short time. Depending on the calorie surplus, you can gain several pounds per month without any problem.

Excluding protein, which is essential for building muscle, you are free to choose what you want to eat in terms of carbohydrates and fats. Whether you choose traditionally "healthy" foods or eat freely with this method is up to you. So you are not restricted.

You have significantly more energy and become stronger. Your glycogen stores are permanently filled and your fat depots also provide the necessary power for hard training sessions. This makes it easier for you to set new training stimuli.

Dirty bulk disadvantages

You will look increasingly bigger and more massive over the course of your bulking phase. However, you will notice when you look in the mirror that your hard-earned muscles are increasingly covered by a layer of fat.

Besides the actual goal of building muscle, your body also puts on a lot of fat when you have a large calorie surplus. More fat tissue also means an increased hormone production with partially negative consequences for muscle building.

The more metabolically active tissue your body has stored in the form of fat, the more hormones are produced. In particular, the sex hormone estrogen is produced in increased amounts. In contrast, testosterone levels drop. A fluctuating hormone balance leads to a variety of negative effects.

In addition to a weakened immune system, a decrease in testosterone production in particular will lead to limited muscle growth. This is counterproductive to your actual goal and will not allow you to reach your full potential.

If you constantly eat large amounts of food as a result of dirty bulking, you also run the risk of developing insulin resistance. Due to the oversupply of energy, your body no longer responds as well to the important hormone insulin.

Insulin regulates many metabolic processes. As a messenger substance, it transports nutrients to the muscles, among other things. This hormone also promotes cell growth. It is therefore essential for muscle growth. If your body is no longer particularly receptive to insulin, this will have a negative effect on your ability to put on muscle.

Furthermore, you should be aware that a dirty bulk will usually be followed by a lengthy diet. At the end of the mass phase, you will have built up a lot of fat as well as muscle mass. To get rid of the unwelcome tissue, it is essential to maintain a calorie deficit. The more fat you have gained, the longer your diet will last.

In addition, rapid weight gain can lead to stretch marks and cracks in the skin. In particular, the change between a dirty bulk and a weight loss diet puts a lot of stress on the connective tissue.

Lean bulk: Patience for lean muscle gain?

In a lean bulking diet plan, you eat with a moderate calorie surplus of 200-300 calories. The goal here is to gain weight more slowly, but to still build a good amount of lean muscle mass.

In contrast with dirty bulking, in a lean bulk you focus primarily on unprocessed foods. It is not only the pure mass that counts, but also the quality of the ingredients. Therefore, it is even more important to track your food intake in detail.

In principle, you can also rely on high-quality foods and eat "clean" with a dirty bulk. However, you do this with a significantly larger calorie surplus.

Lean bulk advantages

Because of the reduced fat gain, you maintain your "lean" look. Your muscles are not hidden by the increase in body fat.

Through the moderate calorie surplus and the slow weight gain, you also prevent strong hormonal fluctuations. Your hormone balance thus remains at a constant level, so that you can produce enough testosterone for muscle building.

Furthermore, you remain sensitive to insulin. This results in increased cell growth and better energy utilization. You can build muscles more effectively overall.

Of course, with the lean bulk you also accumulate a certain amount of fat. However, this is far less than with a dirty bulk.

Another advantage is that you will spend less time dieting if you want to get lean again after the bulk. Your cutting phases will be shorter and you'll stay more motivated because you'll see results faster due to the lower body fat percentage.

Lean bulk disadvantages

Your mass phase takes more time and requires more patience until you reach your goal. Especially for hardgainers, it will be difficult to build muscle with a moderate calorie surplus. Individuals who have poor energy storage due to an overactive metabolism will inevitably require a larger caloric surplus. In addition, a lean bulk requires consistent tracking of all calories.


In general, we recommend adopting the lean bulking approach. A moderate calorie surplus of 200-300 cal and a well thought-out nutrition plan with a focus on plenty of protein are the key to successful muscle building without putting on a lot of fat, assuming of course that leanness is something you are aiming for.

Plan your bulking phase with a clear timeframe and goals in mind. When choosing foods, make sure you combine different sources of protein with complex carbohydrates and healthy fats.

In addition, it is necessary that you pay attention to sufficient recovery. Furthermore, you should design your strength training for progression in order to optimally increase your strength in the long term. We also recommend that you periodize your training for this goal.