Supplements for people who exercise: which have evidence and how to use them
Sports supplements fill entire shelves, but only a few of them have reliable evidence. For most people, training, food and sleep matter most.
In this article you will find out which supplements are truly worth your attention, how much to take, and how to avoid problems if you compete.
In brief. The strongest evidence is for creatine, protein and carbohydrate-electrolyte drinks during prolonged endurance exercise.1,3 3 g per day is enough for creatine. For an adult, caffeine is safe at up to 200 mg in a single dose and up to 400 mg per day.4 If you compete, choose independently certified products.
Do you have to take supplements when you exercise?
No. If you exercise 2–4 times a week and eat a varied diet, you usually do not need supplements.3 A supplement can be convenient when it is hard to get enough protein from food or when you train for a long time and at high intensity.
Example. After an evening workout, a dinner of cottage cheese, eggs or chicken does the same job as a protein shake. A shake is simply faster when you have no time to eat.
Which sports supplements have proven benefits?
| Supplement | What the sources show | What it means for you |
|---|---|---|
| Creatine | Increases physical performance in successive bursts of short-term, high intensity exercise, when 3 g per day is taken.1 | Suitable for strength training, interval training and sprinting. |
| Protein | Contributes to a growth in muscle mass and to the maintenance of muscle mass.1 | What matters is your total protein intake over the day, not the shake itself. |
| Carbohydrate-electrolyte drinks | Contribute to the maintenance of endurance performance during prolonged endurance exercise and enhance the absorption of water, if the composition of the drink meets the established conditions.1 | Useful during a long run or a cycling trip, not during a half-hour workout. |
| Magnesium | Contributes to normal muscle function.1 | Useful if you get too little of it from food. |
| Caffeine, BCAA, beta-alanine | Studies exist, but there are no approved EU health claims.1 | Results depend on the dose and the type of exertion - we write about each one separately. |
Creatine: how much to take and how?
The benefit is achieved with 3 g of creatine per day.1 A “loading” phase with high doses is not necessary: if you take a lower dose every day, the result is simply reached more slowly.3 A common side effect is a slight weight gain due to water in the muscles.3
Example. In people over 55, creatine (3 g per day) can improve the effect of resistance training on muscle strength, if you train at least 3 times a week for several weeks.2
Do you need a protein shake?
Protein powder is food, just in a more convenient form. For example, one serving of the whey protein product we selected contains 23 g of protein.9 If you eat enough meat, fish, dairy products or pulses during the day, a shake is optional.
What should you drink during a long workout?
During a regular one-hour workout in the gym, water is usually enough. During prolonged endurance exercise, a drink with carbohydrates and sodium is useful.1
Example. Sugar-free electrolyte powder replenishes minerals but does not provide energy. For a long run or a cycling trip you will also need carbohydrates, for example an energy gel or a sports drink with sugar.
Caffeine: how much is safe?
For a healthy adult, up to 200 mg of caffeine in a single dose is safe, even when taken less than 2 hours before intensive training. Up to 400 mg per day from all sources is safe, and for pregnant women up to 200 mg.4
Add up your coffee, energy drinks and “pre-workout” supplements. A single serving of these often contains 200 mg or more of caffeine.
Safety and doping control
In an international study of 634 supplements, roughly one in seven (14.8%) contained anabolic steroids that were not listed on the label.5 If you compete in events with doping control, choose products certified by “Informed Sport” or “Kölner Liste”.
Consult a doctor first if:
- you have kidney disease – especially before taking creatine or a lot of protein;
- you have heart disease or high blood pressure – before taking caffeine;
- you are pregnant or breastfeeding;
- you are under 18 – most sports supplements are intended for adults.
Chest pain, a strong heartbeat or dizziness during exercise is a sign to stop the exertion and see a doctor. A supplement does not replace a varied diet.7
Selected sports supplements
Commercial information. These are products available in our shop. This is not an effectiveness ranking. Before buying, check the composition and instructions for use on the product page.
Creatine Monohydrate, Pure Powder - 227g - NOW Foods
Pure creatine monohydrate powder with no additives, 5 g per serving. For regular use, the EU claim is linked to 3 g per day, so you can reduce the serving.8
Whey Protein, Vanilla - 300g - Weider
A blend of whey protein concentrate and isolate, 23 g of protein per 30 g serving, sweetened with sucralose and stevia. The smaller pack (10 servings) is suitable for trying the flavour.9
Hydration + Electrolyte & Vitamin Powder Stick Packs, Lemon & Lime - 7 x 8g - Applied Nutrition
Sugar-free electrolyte powder (28 kcal per stick), certified by “Informed Sport”. It does not provide energy for prolonged exertion, so for a long workout you will also need carbohydrates.10
Magnesium Citrate, 200mg - 100 tablets - NOW Foods
Magnesium citrate, 200 mg of magnesium per tablet. The upper limit for magnesium from supplements is 250 mg per day, and 2 tablets (400 mg) exceed it, so consult a pharmacist about the dose.6,11
Frequently asked questions
Is creatine suitable for women?
Yes. The creatine claim applies to adults performing high-intensity exercise, regardless of sex.1 The dose is the same – 3 g per day.
Do I need BCAA if I take protein?
Usually not. BCAA have no approved EU claims, and whey protein already contains them.1,3
When is the best time to drink a protein shake?
What matters most is your total protein intake over the day. A shake is convenient after a workout or between meals, when you have no time for a proper meal.3
Scientific sources
- Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods (consolidated version). EUR-Lex
- Commission Implementing Regulation (EU) 2017/672 on the authorisation of a claim on the effect of creatine and resistance training in adults over 55 years of age. EUR-Lex
- Maughan RJ, Burke LM, Dvorak J et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med. 2018;52(7):439–455. doi:10.1136/bjsports-2018-099027
- EFSA NDA Panel. Scientific Opinion on the safety of caffeine. EFSA Journal. 2015;13(5):4102. doi:10.2903/j.efsa.2015.4102
- Geyer H, Parr MK, Mareck U et al. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids – results of an international study. Int J Sports Med. 2004;25(2):124–129. doi:10.1055/s-2004-819955
- EFSA, Scientific Committee on Food. Tolerable Upper Intake Levels for Vitamins and Minerals. 2006. efsa.europa.eu
- Directive 2002/46/EC on the approximation of the laws of the Member States relating to food supplements. EUR-Lex
- NOW Foods. Creatine Monohydrate, Pure Powder, 227 g. Product label.
- Weider. Whey Protein, Vanilla, 300 g. Product label.
- Applied Nutrition. Hydration + Electrolyte & Vitamin Powder Stick Packs, 7 × 8 g. Product label.
- NOW Foods. Magnesium Citrate, 200 mg, 100 tablets. Product label.
Disclaimer. This article is for information purposes only and does not replace a consultation with a doctor or pharmacist. Food supplements are not intended to treat or prevent diseases and are not a substitute for a varied diet and a healthy lifestyle. Before taking supplements, especially during pregnancy or breastfeeding, if you have a chronic illness or if you take medicines, consult a healthcare professional.
