muscle definition phase

Muscle Definition Phase – Nutrition, Training & Muscle Protection

The definition phase is used to bring out your built muscles. It follows the week-long bulking phase, in which people trained hard and ate extensively. For many strength athletes, the definition phase is a change and a challenge. We explain what is important.

There are essentially 3 things to consider in the definition phase: nutrition, training and muscle protection. These are closely linked and interlock. The most important component of the definition phase is the change in diet. This is followed by the adaptation of the training and the protection of your muscles.

Diet plays the decisive role in the definition phase. In general, if you eat fewer calories than you burn, you lose weight. This also applies to muscle mass. In order not to lose muscles, pay particular attention to the protein content in the definition phase.

With a normal diet, the body loses around 60% fat and 40% muscle mass. You can counteract this with a protein-rich diet in the definition phase. We recommend 1.3 g – 1.5 g protein per kg of body weight to help you achieve your goals.

However, the ideal protein requirement varies from person to person. Therefore, no clear recommendation can be made. However, it is clear that for muscle maintenance, the protein content in the definition phase must be higher than in the bulk phase.

Our tip for your definition phase

Muscle definition is a full time project. Hard training and a disciplined diet are part of it. Whey protein provides valuable protein. L-carnitine supports the effective production of energy during muscle definition. Perfect for your body shaping.

Fats & carbohydrates in the definition phase - is that possible?

In addition to protein, fat also plays a key role in the definition phase. In general, lots of protein and healthy fats are a must. Carbohydrates should be reduced.

Healthy fats from high-quality oils (for example organic coconut oil or linseed oil), nuts and fish are important sources of energy. Fish in particular contains essential omega-3 fats from which you benefit in the definition phase. Taken in the right amount, they maintain the health of the heart, eyes and brain. For a healthy cardiovascular system.

Carbohydrates are also allowed. Prefer foods with a low to medium GI (Glycemic Index). This value indicates how much a food causes the blood sugar level to rise.

An increase in blood sugar means that more insulin is released into the body, which inhibits fat burning. Good sources of carbohydrates are, for example, sweet potatoes, pumpkin, carrots or beans.

Training in the definition phase

Training should not be neglected in the definition phase. Here the focus is set differently than in the mass phase: Less weights & more repetitions.

However, that does not mean that the barbell and the heavy weights are now put in the corner and only pure cardio training is done.

HIIT training

In this case, HIIT training is effective. Here the focus is on short, intensive intervals with exercise and recovery phases. HIIT is primarily performed in the endurance area while swimming, running or cycling.

For example, with HIIT, 60 seconds of exercise is at the maximum limit and 90 seconds of recovery. Best of all, it can be done in just 15 to 20 minutes.

The specialty of this type of training is that both the muscles and the cardiovascular system are trained with just a few exercises. In addition, the fat burning is boosted enormously. This is exactly why HIIT training is ideal in the definition phase.

In addition to HIIT, pure strength training is also useful in the definition phase. This will continue to use and strengthen the existing muscles. If the calorie deficit is not too great, the athletic performance should also not drop.

Maintain strength in the definition phase

However, further muscle building is hardly possible during the definition phase. The focus here is more on protecting and maintaining existing muscles. Therefore, during the definition phase, work regularly with the weights that you already used in the bulk phase.

Muscle protection supplements help in the definition phase

Supplements are good supporters of muscle protection and maintenance. When it comes to dietary supplements, BCAAs, L-Carinitin and a mix of whey and casein, for example a 3K protein, are good choices in the definition phase.

BCAA capsules can support the definition phase. They provide direct energy for intense workouts and prevent your body from drawing energy from muscle protein. This is how they ensure that your muscle mass is maintained during body fat reduction.


To ensure that your muscles are supplied with sufficient protein during the definition phase, it makes sense to drink protein shakes such as 3K protein or vegan protein on a regular basis.

3K Protein is whey protein with casein, which is ideal for the definition phase. The whey supplies your muscles with protein quickly after training. As soon as the protein is processed, the casein is used and provides the muscles with protein for up to another 7 hours. This constant protein supply is essential to protect the muscles during the definition phase.

L-carnitine is also a useful supplement. Among other things, the amino acid is responsible for transporting dietary fats to the mitochondria. There they are converted into energy. Due to the improved energy supply, L-Carnitine ensures effective and intensive workouts. So that you can perform at your best.

Duration of the muscle definition phase?

The decisive factor for the duration of the definition phase is how much excess fat has accumulated in the mass phase and what body fat percentage is aimed for. What is certain, however, is that this phase will take several months.

An exact duration cannot be specified for a definition phase. As a guideline, however, you need to burn 7000 kcal for 1 kg of body fat. The daily calorie deficit should not be too high so that only fat is reduced as much as possible during the definition phase and the athletic performance does not suffer. A moderate deficit is 300 to 500 kcal.

7000 kcal sounds a lot in one fell swoop. You can save this within 2 weeks by eating 300-500 kcal less per day in the definition phase than in the previous bulking phase.

Another option is to reduce the number of calories in smaller steps. If, for example, 3000 kcal were consumed, this amount is reduced in sections by 200 kcal each. In the first week, 200 kcal are saved and then an additional 200 kcal the week until the deficit of 3000 kcal is reached.

With this method, the body goes less on the back burner, there is no feeling of hunger and there is no great loss of training.


  • The key to a successful definition phase is the combination of: nutrition, training and muscle protection.
  • Several months should be planned in order to achieve the desired body fat percentage.
  • The focus should be on a high protein diet.
  • When training: a lot of repetition & little weight.
  • Supplements such as 3K protein, L-carnitine and BCAA capsules can support the definition phase.