Low carb and sports – is that possible?

Anyone who does a lot of sport also needs a lot of energy. And our body gets this energy from carbohydrates, because only these provide the quickly needed energy kick. According to this, low carb would be completely unsuitable for athletes, but is that true? Well, it is, DAS is at least the widespread opinion in sports circles. But the fact that low carb is not suitable for athletes is not necessarily true, because athletes can also benefit from the low carb diet.


The energy that the body obtains from sugar (glucose) is temporarily stored in the form of glycogen in the muscles and liver – the so-called glycogen stores. However, once the stores are empty, for example after a marathon, nothing works – you are faced with the so-called “wall”. In this situation the body literally screams for glucose.

Since the body is not used to generating energy in any other way (but can learn to do so, just read on), it cannot react accordingly in this situation and attacks the holy of holies: its muscle mass. This is because in such emergency situations the body is able to produce energy in the form of glucose from (the body’s own!) protein by means of so-called gluconeogenesis. But of course nobody wants to lose muscle mass.

To avoid this, “fat metabolism training” on a low carb basis is becoming increasingly important, especially in endurance sports. 


Sportler ohne genug Kohlenhydrate im Blut machen schnell schlapp Energy reserves empty? © Shutterstock / Guryanov Andrey

Carbohydrates are our body’s number 1 energy supplier, but the amount of energy it can draw from them is only limitedly storable. This restricts the performance, or rather: it limits it. Through carboloading and training one tries to use and expand the storage capacities better, but generally the possibilities here are limited. That is why more and more athletes are turning to low carb nutrition.

The principle is quite simple: instead of heating up the “engine” (body) with carbohydrates, they simply change the “fuel” (fat instead of carbohydrates) and rely on ketosis. 


For your body to be able to gain energy from fat or fat reserves at all, the fat must first be converted into a form that can be used by the body. During this conversion, so-called ketone bodies are extracted from the fat cells and these are exactly the ones that now serve the body as alternative energy suppliers. And exactly this process is then called ketosis. The body automatically switches to ketosis metabolism if you do not take in any or very little carbohydrates (less than 30 grams) for a few days. The advantage of ketosis is that your body draws energy from fat and fat reserves all the time, and these are by far not exhausted as quickly as the glycogen stores. And everyone can actively train their fat metabolism. The decisive factor here is that the adaptation phase to ketosis has been completely completed. This sometimes takes several weeks, but it is worth it if you persevere. Because especially at the beginning you are usually a little bit flabby, but that will pass and you will be able to fully take off in sports.


Hanna und Lena – die Zwillinge hinter dem Hanna and Lena – the twins behind “TwinFit

TwinFit – these are the fit twins Lena and Hanna. On your blog “Twinfit Low Carb” give us a colourful insight into your low carb lifestyle – and of course this also includes a lot of sports like TRX Stand Up Paddling, Surfing & Co. Why the girls rely on low carbohydrates, what they say about the prejudices against low carb in sports and much more, you will learn in the interview:

WomensHealth.de: Why did you decide to change your diet to low carb?

TwinFit: “We have always eaten healthily, actually. Regular sport was also part of our everyday life, but we were never quite satisfied. Losing 1-2 kilos, of course, that would be nice… Just as we women are. And, do you manage it in the end? Nope, because neither the renouncement of sweets nor the obligatory cabbage soup diet brought a visible success.

But then a friend of ours told us about his crass sales success with the help of low carb. So we thought: Hey, DAS so can we! From one day to the next we turned our diet upside down and started to do sports almost daily. And success was not long in coming: The kilos dropped and we visibly built up muscles, wow! Finally! This was three years ago now and we would do the same thing again and again.

A healthy and balanced diet and lots of exercise have been part of our everyday life ever since and this has positively changed our lives and ourselves personally”.

WomensHealth.de: Few carbohydrates, little energy? What do you think about the prejudice that low carb is not for athletes? 

TwinFit: “Our motto is low carb, not no carb. In other words, if you eat low carb and do sports, you should make sure you eat the right carbs and eat them in moderation – this way you make sure you have enough energy for your sports unit. We get our energy from healthy carbohydrates with low sugar content and combine them with plenty of proteins and healthy fats. This effectively supports muscle building and provides the body with sufficient energy during the training unit.

You should especially keep your hands off sugar from soft drinks and juices, as well as fruit yoghurts and the like. Ready meals are also taboo. This sugar shoots into the bloodstream particularly quickly and has a negative effect on your metabolism.

Selber kochen ist Pflicht bei TwinFit Tip of the Twins: “Stick to fixed meal times. That way you won’t be tempted to go hungry and reach for something unhealthy.”

The fit twins swear by these 8 energy boosters, because they are rich in fibre, low in sugar and rich in protein:

  • Beans
  • Oatmeal
  • Pumpkin
  • Bananas
  • Berries
  • Sweet potatoes
  • Quinoa
  • Popcorn (unsugared)

WomensHealth.de: Do you perhaps have some tips for the Women’s Health readers that might help you to get into the low carb lifestyle or everyday life?

1) Inform yourself at the beginning about the low carb nutrition! Explore the nutritional values of food and learn about the effects of proteins, fats and carbohydrates in your body. This is admittedly a bit of work, but it’s super interesting and the basis for a healthy lifestyle.

2) Write down clear rules for your diet!

Hang these rules in your apartment in a clearly visible place (e.g. cakes, cookies and sweets only on special occasions such as birthdays).

3) Step by step on!

First of all, try to generally avoid carbohydrates in the evening and keep your hands off sweet things. If that works out well, then try to replace the slices of bread with higher-protein and lower-carbohydrate foods in the morning as well, etc. 

4) Organization is everything!

Leave nothing to chance when it comes to nutrition! For a start, it is helpful to plan the food for the week on Monday. Keyword Mealprep !

Think carefully about what and where you want to eat during the week and use your diary to create a kind of meal plan. For example, plan low carb snacks for the train journey and if there is nothing for you in the canteen, then cook something up. Granted, it takes some time at the beginning, but you will notice that it soon becomes routine. 

5) Give your body what it needs!

Listen to your stomach and don’t forbid him to eat when he needs it. You should never starve.

Be consistent, but give your discipline a day off once in a while Filling up your carbohydrate reserves from time to time will help you to cope with the change in your everyday life. Save this Cheatdays for meals in company (birthdays, appointments with friends, family celebrations, etc.). It is precisely then that it is particularly difficult to do without things that everyone else helps themselves to. This only leads to a bad mood and no one is in the mood for it 😉

Even more input from feisty girls can be found on Instagram, for example: