
ゲイナー:筋肉増強、カロリーボム、栄養戦略の間で
Anyone who trains regularly in the gym will eventually come across the term Gainer. These supplements, also called “Weight Gainers,” promise quick calorie intake and are supposed to help with muscle building. But what is really behind them? Are they useful or just expensive calorie shakes?

What is a Gainer?
A Gainer is a dietary supplement in powder form that mainly consists of carbohydrates and proteins. Unlike classic whey protein, the focus here is on high-calorie intake. Typically, a gainer consists of about 60–75% carbohydrates, 15–25% protein, and a small amount of fat. Often, vitamins, minerals, and sometimes creatine or other additives are included.

The Benefits of Gainers in Muscle Building
To build muscles, the body needs not only training but also a calorie surplus. Those who have difficulty consuming enough calories through regular meals – such as hardgainers with a fast metabolism – may find it easier to achieve this surplus with gainers.
An example:
- A whey shake provides about 120–150 kcal.
- A gainer shake, depending on the brand, brings with it 400–1000 kcal in just one glass.
This allows athletes to consume the amount of calories for which they would otherwise have to eat several plates of rice, oats, or potatoes in just a few minutes.

The Ingredients in Detail
- Carbohydrates: Often sourced from maltodextrin, glucose, or oat flour. These provide fast and sometimes long-lasting energy.
- Protein: Usually whey protein, milk protein, or casein to supply muscles with amino acids.
- Fats: Only a small amount, usually in the form of vegetable oils.
- Additives: Some products contain creatine, BCAAs, vitamins, and minerals – aiming to make the shake a “complete solution.”

Advantages of a Gainer
- Quick and easy calorie intake
- Convenient for people with little appetite or a hectic lifestyle
- The combination of carbohydrates and protein can accelerate recovery after training
- Ideal for hardgainers who cannot gain weight despite eating much

Possible Disadvantages
- High sugar content: Many gainers are based on inexpensive carbohydrate sources like maltodextrin or glucose, which can cause a significant spike in blood sugar.
- Digestive issues: Large quantities can lead to bloating or a feeling of fullness.
- Risk of increasing fat: Consuming too many calories not only builds muscle but also fat.
- Cost: Compared to regular foods, gainers are often expensive, even though they mainly consist of inexpensive ingredients.

Sensible Alternatives
If you don’t want to rely on expensive powders, you can mix a homemade gainer:
- Oats
- Milk or water
- Banana or berries
- Protein powder
- Nuts or nut butter
This creates a shake that can provide just as many calories – only healthier and often cheaper.

Who Really Benefits from a Gainer?
- Hardgainers: People who have difficulty gaining weight despite large portions benefit the most.
- Athletes with high calorie needs: Such as endurance or strength athletes in intensive training.
- People with limited time: A shake is faster than a plate of pasta.
However, for most fitness enthusiasts, a gainer isn't necessary. Those who meet their calorie needs through regular diet don’t necessarily require it.

Conclusion: Caloric Aid or Marketing Trick?
Gainers can be a useful tool for some athletes to achieve a calorie surplus and facilitate muscle building. However, they are not a miracle cure. Ultimately, the overall diet matters – and whether the calorie balance is right. Those who eat a balanced diet and consume enough can build muscle without gainers. However, for hardgainers or athletes with very high energy needs, they remain a practical supplement.