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9 Best Supplements For Swimmers 

Looking to gain a competitive edge in the pool? Keep reading to learn about the best supplements for swimmers! 

Nutrition supplements can help fill in nutritional gaps and support recovery.

From creatine to beat powder, we will review some of the best dietary supplements for competitive swimmers.

Read on to learn about nutrition supplements that may help resolve deficiencies and the supplements that may take your swimming performance to the next level!

Disclaimer: This post was written and reviewed by Katie Schimmelpfenning, registered dietitian and swim coach. It is for informational purposes only and should not be construed as medical advice. Consult a doctor or dietitian about supplement questions.

Should swimmers take supplements?

While supplements can be beneficial for swimmers, supplements cannot replace the nutritional benefits of whole food sources.

To help elite athletes figure out the right time to implement nutrition supplements, we recommend a pyramid approach, working from bottom to top. 

First, ensure you are consuming nutrient-dense foods, carbohydrates, fats, and protein. Then, focus on meal and snack timing before practice and between swim meet events

The last step is to incorporate supplements that may enhance recovery and performance.

In this guide, we’ll dive into the best supplements including protein powders, creatine, vitamin D, and more. By the end of our supplement guide, you’ll have a better understanding of which supplements may optimize your performance in the pool.

Certifications to look for 

Supplements are not under the Food and Drug Administration (FDA) regulation, meaning there is no guarantee that the product’s content matches the label or is free from harmful substances. 

To ensure safety, we recommend that all athletes opt for third-party tested supplements.

For collegiate, professional, and drug-tested athletes, we suggest using NSF-certified supplements for sport, Informed Sport, or BSCG-certified supplements. 

Third-party testing helps to ensure you are taking high-quality products that are free from banned substances.


Beetroot can be a beneficial supplement for swimmers due to its high levels of vitamins, minerals, antioxidants, and nitrates. 

Studies have shown beetroot may (1, 2, 3):

  • Increase blood flow
  • Enhance endurance
  • Improve intensity 
  • Shorten recovery time 

How to take beetroot

We suggest taking concentrated forms of beet juice or beet powder 30-60 minutes before training to maximize the benefits of the nitric oxide-boosting beetroot.

Incorporating beetroot juice into your diet may help improve your stamina during endurance exercise and may lead to better training outcomes. 

More research is needed to determine the exact dose for enhanced and improved performance!

Beetroot considerations

​Beetroot may make your stool a magenta color. Both beetroot powder and juice have a strong taste that may be disliked by some athletes.

Some swimmers may experience stomach upset when consuming beets. Practice with beetroot in training sessions before race day.

Check out our write-up on Beetroot Juice For Anemia for additional ways to add beetroot to your diet!


Do you enjoy your morning cup of coffee or tea? Or maybe you like to grab an energy drink or pre-workout to power through a tough workout? Whatever your preference, you might be wondering if caffeine can help improve your athletic performance.

Research has shown that caffeine can increase mental alertness and even delay fatigue during endurance exercise. 

How to take caffeine

If caffeine doesn’t cause negative effects on your body and you want to take advantage of its benefits, take it 45-60 minutes before physical activity.

We recommend athletes try 3-6 mg/kg of caffeine before a workout. That is ~200-410 mg caffeine for a 150lb athlete. Use our caffeine calculator to find out how much you need!

To put it in perspective, 300mg of caffeine is roughly equivalent to ~3 cups of coffee. So, while a cup of coffee or tea may help you power through your workout, it’s important to be mindful of your caffeine intake to avoid any negative side effects.

Caffeine considerations

Should swimmers take caffeine? The answer is: it depends! While some athletes may benefit from caffeine consumption, others may experience negative side effects.

Caffeine sensitivity varies among individuals, and excessive caffeine intake can lead to digestive issues, headaches, nervousness, and even heart rhythm disturbances. 

Check out our blog post Pros and Cons of Caffeine for Athletes to learn more.

Please note the popular energy drink Celsius contains guarana, a natural source of caffeine that is on the list of banned substances in the NCAA (4). Therefore, if you are an NCAA athlete, it’s essential to avoid any product containing guarana.


Creatine is naturally made in the body and stored in the muscles as phosphocreatine. This is what gives the body energy for short-distance sprints (like the 50 free) and other high-intensity exercises!

Creatine monohydrate is a safe and effective supplement that may improve swimming performance (5, 6). 

How much creatine?

Taking 3-5 grams of creatine monohydrate daily after a swim session is enough to maximize its benefits.

Paired with swimming and strength training, creatine supplements can help swimmers increase muscle strength and speed up recovery! 

Pictured is a creatine guide. On the far right is a bicep graphic flexing that says "Creatine is stored in the muscles as phosphocreatine." In the middle is a figure weight lifting underneath it says "Used in short, high-intensity exercises like weight lifting." To the far right is a container of creatine, below it says "Consuming 3-5 g/day may improve maximal strength, power, and sprint performance."

Creatine considerations 

Creatine can be particularly beneficial for plant-based athletes as they are more likely to have lower phosphocreatine stores!

Individuals who have medical conditions should talk with their doctor before deciding if creatine monohydrate supplementation is right for them. 

Vitamin D 

In the United States, 1 in 4 adults have vitamin D levels too low to maintain overall health, especially bone health (7)!

Vitamin D is important for:

  1. Bone Strength: Vitamin D helps your body absorb calcium, which is crucial for making your bones strong and sturdy.
  2. Energy Boost: It helps turn the food you eat into the energy your body needs for activities such as swimming!
  3. Immune System Support: Vitamin D acts like a shield, helping your body resist getting sick and staying healthy.
  4. Muscle Function: It ensures your muscles work well and don’t get tired too quickly, so you can keep enjoying your favorite activities.
  5. Mood Improvement: Vitamin D can lift your mood, making you feel happier and more positive.

Vitamin D supplements 

Which swimmers may need to supplement vitamin D?

  • Those who practice indoors (especially in the winter)
  • Swimmers who live in places with lower sunlight levels
  • Athletes whose blood level (serum) values of Vitamin D <75 nmol/L 

Talk to your doctor or dietitian for specific Vitamin D recommendations. While rare, Vitamin D toxicity can occur from excessive vitamin D supplementation.

Vitamin D considerations 

To achieve adequate vitamin D levels, ideally >100 nmol/L a combination of vitamin D-rich foods, sun exposure, and vitamin D supplementation may be required 

Fish oil 

For swimmers who do not like the taste of fish or have a difficult time eating at least 6 oz of fish per week, we recommend supplementing with omega-3.

Fish oil is packed with omega-3 which can help to improve heart health, brain function, and skin health. Additionally, omega-3 may help to decrease inflammation (7). Research has also supported improved cognitive function and mood with Omega-3 supplementation (8).

Omega-3 supplement tips

When looking for an Omega-3 supplement aim for a supplement that has 250-500 mg of both eicosapentaenoic acid (EPA) and docosahexaenoic acid(DHA). These are the omega-3 fatty acids linked with the most health benefits.

Omega-3 considerations

Fish oil supplements may give people fish burps; store your fish pills in the freezer and take it frozen to minimize the risk of nasty fish burps. 

Talk to your doctor before starting fish oil if you are taking Coumadin (warfarin). 


Iron is a mineral that creates hemoglobin found in our red blood cells. Hemoglobin carries oxygen from our lungs to the rest of our body. Iron also helps the cells in our body make energy! Consuming enough iron helps prevent muscle damage and inflammation

When an athlete is iron deficient also called anemia, they may feel fatigued or notice decreased endurance. 

Monitor your iron status

We recommend having your hemoglobin, hematocrit, serum ferritin levels, total iron-binding capacity, and serum iron levels checked to see if an iron supplement is necessary for you. 

Caution, iron supplements can be constipating and are not recommended for all swimmers. 

Due to menstruation, female swimmers are at higher risk for iron deficiency. Athletes need to monitor iron levels and supplement as needed. 

Iron supplementation 

If your doctor or dietitian recommends iron we recommend trying these less constipating, more absorbable forms of iron supplements:

  • Ferrous bis-glycinate
  • Iron citrate 
  • Carbonyl iron
  • Iron glycinate 

Always check with your doctor or dietitian to ensure you are consuming the iron supplement best for you! Check out our blog post about Iron-Rich Foods For Athletes to learn how you can increase your iron levels through food.


Magnesium is a mineral important for:

  • bone health
  • heart health
  • regulating muscle function
  • nerve function
  • mental health
  • sleep quality

Sadly, 50% of Americans are not consuming enough magnesium (9). 

If you are a swimmer experiencing loss of appetite, muscle cramps, or fatigue, it may be time to talk to your healthcare provider about starting a magnesium supplement or eating more foods rich in magnesium.

When to take magnesium?

We recommend athletes take magnesium at night before bed to reap the calming effects and for improved sleep.

Magnesium can be especially helpful for female athletes as it has been linked to improved management of premenstrual syndrome symptoms (PMS) (10).

Magnesium considerations 

A common side effect of some magnesium supplements is diarrhea, especially magnesium citrate which is often used to ease constipation. 

Magnesium glycinate is more easily absorbed and less likely to cause gastrointestinal issues. However, if you begin to have a metallic or bitter taste in your mouth this can be a sign that you are taking too much magnesium.

Do not supplement with more than 300 mg of magnesium per day unless instructed to do so by your healthcare provider. 


Athletes who consume essential nutrients through a diverse and balanced diet may not require a multivitamin supplement. Taking one unnecessarily could result in the excretion of excess water-soluble vitamins, aka expensive urine!

What multivitamins to take? 

If you feel you are unable to meet your micronutrient needs through your diet and would like to supplement with a multivitamin we recommend the Klean Athlete multivitamin which is NSF-safe for sport and contains the easily absorbed forms of the nutrients in addition to antioxidants.

This multivitamin is also gluten-free.

Considerations when starting a multivitamin 

Multivitamins can cause an upset stomach, take them with food to prevent gastrointestinal discomfort. 

Protein Powders 

Protein powders can be an easy and convenient way to help you meet your protein needs. Use our Protein Calculator for Athletes to find out how much protein you should eat per day.

Athletes think they need supplements to build muscle, but this is false! Be careful when selecting a protein powder, many protein shakes, energy bars, and protein supplements many products’ actual ingredients and nutrient contents may not match the food label.

How much protein powder?

Most protein powders provide between 15 to 30 grams of protein per serving, with whey protein powders being one of the most popular types and containing around 20-25 grams of protein per scoop. 

Other types of protein powders, such as casein, soy, and pea protein, may have slightly different protein contents. 

To supplement your daily protein intake from whole foods, we advise limiting your protein powder consumption to one daily serving.

Protein powder considerations

To select a high-quality protein powder, look for:

  1. Third-party testing: NSF safe or sport, informed choice, or informed sport
  2. At least 20 g of protein per serving 
  3. >2 g of leucine, an amino acid that stimulates muscle growth and repair 
  4. Free of chicory root, sugar alcohols, dyes, gums, excessive fiber, and artificial sweeteners that can upset your gastrointestinal tract (GI tract)

Whey protein isolate is a better option than whey protein concentrate because whey protein isolate offers a higher protein concentration and is a better option for those who have lactose intolerance.  

Additionally, it’s worth noting that some plant-based protein powders may contain higher levels of heavy metals, which can be harmful.

Check out our ultimate guide to The Best Protein Powders for Swimmers.

Tart cherry 

Tart cherries contain flavonoids and anthocyanin, which are powerful anti-inflammatory and antioxidant compounds that support post-workout recovery. 

Research has shown that consuming tart cherry juice or supplements can minimize muscle soreness and reduce inflammatory markers to reduce muscle damage and speed up recovery time (11)!

How much tart cherry juice?

To achieve these benefits, most studies suggest consuming 8-12 oz (or 1 oz. concentrate) of tart cherry juice twice daily for at least 4 days before the competition and for 2-3 days after.

Tart cherry can make you sleepy

Tart cherry juice contains melatonin which can make active individuals sleepy! Be sure to drink the tart cherry juice or concentrate at night before sleeping.

How to begin a new nutrition supplement 

To pick the right supplements for you or your swimmer follow these general guidelines: 

  1. Meet with your health care provider or dietitian 
  2. Treat deficiencies first!
  3. Only take supplements that are third-party tested 
  4. Try one new supplement at a time, do not try and do all the things all at once it will be harder to tell which supplement is causing issues or benefiting your performance
  5. Always practice with a nutrition supplement before using it before, after, or during an open water race or swim meet 

The Bottom Line

Nutritional supplements cannot make up for a diet lacking in key nutrients. Nutrition supplements do not offer a quick fix. Master snack timing and eat enough food (especially carbs) to promote optimized performance! 

Once you have your good nutrition and meal timing down, supplements may have a beneficial effect on recovery and help to better performance at swim workouts, open water races, and swim meets.

The last thing to remember is to practice with supplements before using them in a race to find what works best for your body for peak performance!

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