A vegan diet can have advantages in cycling. In addition to the ethical and health aspects, vegetarianism also offers fitness benefits. At the same time, vegans are still confronted with prejudices: Undersupply, lack of nutrients, drop in performance - is this really true? Cycling can be highly intensive and, at a certain level at the latest, requires a conscious examination of food intake. What do vegans lack? How can they counteract the challenges of physical exertion? We asked an expert about this. Jan Rein studied ecotrophology and nutrition economics. He also lived a vegan lifestyle for years. As a book author and podcaster, Rein provides scientifically sound information on topics relating to health and nutrition. In his role as a nutrition specialist at the food supplement manufacturer AG1 (Athletic Greens), he is an expert in the nutritional needs of athletes.
BIKE: What are the advantages of a vegan diet in general?
JAN REIN: Of course, ethnic or environmental factors are very important motivations for vegans. Plant-based, unprocessed foods, i.e. fruit, vegetables, pulses and seeds, play a central role in the vegan diet. So if we focus on the nutritional benefits, the demographic data from correlation studies show that vegan communities consume more fibre. We know that this is particularly important for preventing so-called diseases of civilisation, such as type two diabetes. Cross-sectional studies show that the body mass index (BMI) is lower in vegan populations compared to omnivores. Translated, this means that people with a vegan diet are on average somewhat lighter and, according to this data, less likely to be overweight or obese - other important factors for diseases of civilisation.
A vegan diet can also have important benefits on a behavioural level. Many people who change their diet broaden their horizons and suddenly discover new foods for themselves. I myself lived vegan for years and chickpeas, for example, had never played a role in my diet until then. The same often applies to soya products. This allows vegans to expand the diversity of their diet. This in turn is important in order to cover a broad spectrum of micronutrients. Irrespective of veganism, there is of course also evidence that certain plant-based foods, such as beetroot, can have a positive physical effect. Everyone now knows that it makes sense for plant-based foods to make up a minimum proportion of the diet.
What can be the positive effects on physical performance of avoiding animal foods?
When switching to a vegan diet, there is often a "honeymoon phase". As if you were newly in love, the positive effects take centre stage for the time being. Many people have the feeling that they are doing something good for themselves with a vegan diet. A psychological effect similar to the placebo effect can be observed. Unfortunately, there are no conclusive studies on this, but in practice we often observe an initial surge in physical performance, which then levels off again.
If you eat a balanced vegan diet, you are also following an anti-inflammatory diet. A vegan diet contains a relatively high amount of antioxidants. As the name suggests, these have an anti-inflammatory effect. They are also involved in regeneration. Improved regeneration can be one of the strongest positive effects of veganism on performance. There are also people who have constant low-threshold inflammation in their bodies because they cannot tolerate dairy products, for example. If you then eliminate such triggers from one day to the next, you can improve your performance. However, this has less to do with the intake of certain latently harmful substances than with their omission.
Can a vegan diet also have physical disadvantages because the body is lacking something?
There is one problem that many people may not even have on their radar, namely the lack of calories. For various reasons, you consume fewer calories on a plant-based diet. This can make sense if you want to lose weight and does not necessarily represent a risk. However, if you are doing sport, your calorie intake is decisive for how much energy is available. If you don't eat anything, you can't burn anything. So if you want to change your diet, you should also make sure you eat enough.
Then there are also some critical micronutrients that are crucial for nerve and brain function, among other things. Calcium, for example, is important for the signals that the body sends to its muscles in order to perform. Vitamin B12 is another classic, involved in energy metabolism and an undersupply can lead to chain reactions. Iron deficiency can be partially avoided by using vitamin C and certain acid compounds to improve the absorption and availability of iron from plant-based foods. Omega-3 fatty acids, vitamin B2, zinc and selenium can also typically be critical. In addition to the basic plant-based diet, additional supplies can also be obtained from dietary supplements.
A classic criticism of a vegan diet is an insufficient intake of proteins. This is not only important for muscle building, but also for muscle regeneration, immune defence and much more. In practice, however, this is no longer a real problem these days. It is important to combine different high-quality protein sources, such as rice and beans. Amino acid deficits in individual vegan protein sources can be compensated for by combining them with a second protein source.
Natural substances such as choline, creatine, carnitine or cholesterol are hardly ever found in plant-based foods. In theory, however, the body can produce them itself. In practice, the body needs sufficient B12, folic acid and other micronutrients to synthesise them. Genetic factors also determine how effectively the body can produce these natural substances itself. If you want to change your diet, this can be done without any problems. However, an awareness of critical nutrients is always part of the process.
There is also something like a reverse honeymoon effect. If you suddenly consume 40-50 grams more fibre than you did a week earlier, you will probably experience digestive problems. Of course, this doesn't necessarily contribute to your physical performance: Nobody wants to cycle bloated. You have to get used to it first.
What symptoms can a vegan diet cause?
If you take in too few micronutrients, you can have problems with muscle control. An undersupply of calcium, for example, can lead to cramps. Unfortunately, people who have been on a vegan diet for many years can often experience a lack of energy and fatigue. They can also occur very suddenly and in combination with hormonal imbalances. For example, a lack of energy can occur in combination with a reduced testosterone level. This then manifests itself in athletes through stagnation in training. Although regeneration has been good and everything else has remained the same, you may suddenly stop making progress with the weights in the gym, for example.
There are also typical deficiency symptoms in the area of beauty. Brittle nails or cracked corners of the mouth are classic signs of an undersupply of B vitamins. Pale skin is a sign of too little iron and hair loss is a sign of too little zinc. None of these symptoms necessarily occur, but they can be an indication that you should take a closer look at your personal vegan lifestyle. You should therefore not be afraid.
How can athletes take countermeasures?
Veganism is a restrictive diet in which you abstain from a large category of food. It is therefore essential to take an informed approach and not simply omit animal foods but otherwise eat the same diet. It's better to expand your range of foods - it can also be fun! In any case, eat enough and eat a varied diet. To ensure a good protein supply, combine different sources.
Nutrients that are not covered by the diet should be supplemented sensibly. Ideally, you should have your blood tested regularly, about twice a year. It's best not to wait until you've been vegan for six months, but before you make the switch. This is the only way to determine which parameters can really be attributed to the diet. People with an omnivorous diet can of course also have a vitamin B12 deficiency without realising it. I would recommend blood tests to competitive athletes as well as ambitious amateur athletes.
Jan Timmermann
Editor
