Dietitian-approved supplements for swimmers

Dietitian-approved supplements for swimmers

Whether you're gearing up for a challenging race like the Midmar Mile or striving to beat your personal best with every swim, there's no denying that swimming is a top-tier cardiovascular activity. Beyond its physical demands, it's a technical sport that calls for power, endurance, and unwavering commitment.

So, when it comes to proper nutrition and the right supplements for swimmers, no blue-print plan works for everybody, explains registered dietitian and founder of Paarl Dietitians, Anèl Kirsten.

“Each person is different with unique energy, protein and nutrient requirements based on their age, gender, body composition, fitness level and aquatic discipline. Therefore, nutritional guidelines must be tailored to individual needs,” she says.

Your nutritional needs will also fluctuate depending on your training intensity, including high-energy periods, tapering, the competition itself, and post-competition recovery (which includes the right supplements). It's important to adjust your energy and nutrient intake based on your changing exercise routines. Additionally, factors like busy schedules and early morning pool sessions may affect your meal planning, and it's crucial to organise meals and snacks for optimal fuelling and recovery, says Anèl.

No matter where you are in your swimming journey, it’s possible to dive into peak performance with the right supplements tailored for swimmers. In this blog, discover the essential nutrients to enhance your swim and achieve a stronger, more sustained performance in the pool.

Anèl’s key takeaways for swimmers:

  • Recovery nutrition is often neglected but is crucial for physical and mental recovery after workouts or competitions.
  • Muscles are most responsive to nutrients in the first 30-60 minutes, creating a crucial recovery window period or timeframe. Proper nutrition during this time speeds up recovery, improves muscle glycogen storage, and enhances muscle protein
  • After resistance workouts, muscles experience increased protein breakdown. Aim for 0.2-0.4g/kg or 20-30g of high-quality protein within the first hour for optimal results.
  • Essential amino acids from quality protein reduce soreness and inflammation.
  • Multivitamins and minerals fill nutrient gaps for swimmers, especially during intense training.
  • Omega-3 fatty acids aid in exercise recovery and support overall health.
  • Creatine supplementation, particularly creatine monohydrate, enhances muscle performance and strength gains.
  • Carbohydrate intake post-workout is crucial for replenishing glycogen stores. Consume 0.5-1g of high-glycaemic carbohydrates per 1 kg of body weight immediately after exercise.
  • Swimmers often finish sessions in a fluid deficit; monitoring urine helps assess hydration status.
  • Electrolytes with recovery fluid assist in hydration and replacing lost sodium.
  • Hard training may compromise the immune system; supplements like glutamine, vitamins C and E, zinc aid immune support. High-antioxidant foods and appropriate rest contribute to immune system health.
  • Nutrient deficiencies impact performance, blood tests provide insights into vitamin and mineral levels. Correct deficiencies with dietary changes and supplements, such as vitamin D for muscle repair and recovery.

The importance of recovery nutrition for swimmers

“From years of experience in the field of nutrition, I have found that recovery nutrition amongst athletes is often neglected,” says Anèl. But post-workout nutrition is just as important as the training itself. “In a hard workout, you can use up all your stored glycogen, easily sweat over half a litre of water and break down both muscle and red blood cells. After a race or competition, you will undoubtedly be physically depleted, dehydrated, and mentally exhausted. This is why what you consume in the minutes and hours after your training or competition is so crucial to both performance and recovery,” she explains.

The primary goals of recovery nutrition are:

  • To refuel: Replenishing the muscle and liver glycogen stores
  • To rehydrate: Restoring fluid and electrolytes lost through sweat
  • To repair and build: Consuming protein to assist with muscle repair
  • To replenish: Providing vital nutrients to support the immune system in handling the damage and attenuating excessive inflammation

When you train or work out intensely, you damage tissues at the micro level, which leads to post-exercise inflammation, and you use fuel to keep you going. This is what ultimately makes you stronger, leaner, fitter, and more muscular, but in the short term, it requires repair.

Good post-workout nutrition therefore helps to speed up the recovery process and improve your body’s ability to build muscle. You’ll also benefit from:

  • Less muscle soreness
  • Improved immune function
  • Improved bone mass
  • Improved ability to utilise body fat

The ‘window’ of opportunity

Anèl explains that after exercising, your muscles are most responsive to nutrients in the first 30-60 minutes, creating a recovery window. This period is crucial for muscle repair, growth, and strength, as well as replenishing glycogen stores. Research suggests post-workout nutrition is most effective within two hours, improving muscle glycogen storage and protein production. Therefore, it’s a good idea to seize the opportunity for optimal recovery by nourishing your body during this window.

The essential role of protein for swimmers

Olympic swimmer Erin with SPORT Rx products

After resistance workouts, muscles experience increased protein breakdown and slightly or unchanged protein production. Conversely, in endurance training like swimming, muscle protein production drops, and breakdown goes up. However, studies indicate that the right nutrients post-exercise can reverse this trend, improving muscle protein production and suppressing breakdown. This emphasizes the importance of recovery nutrition in aiding muscle rebuilding.

Anèl believes that taking in essential amino acids from quality protein sources such as SPORT Rx’s PROTEIN Rx and WHEY Rx has been shown to help with the muscle-building process, reducing muscle soreness and inflammation.

For the best results after your workout, whether it's endurance or resistance training, Anel maintains that you should aim to have 0.2-0.4g/kg or 20-30g of high-quality protein (like whey protein) within the first hour. PROTEIN Rx has 20g of protein, while WHEY Rx provides 24g.

Glutamine, another amino acid, can also be taken after intense training. Glutamine plays a vital role in recovery as it helps boost the immune system, helps to reduce the symptoms of overtraining, plays a role in enhancing glycogen storage, and stimulates muscle protein production for the rebuilding of lean muscle tissue. Glutamine is present in both PROTEIN Rx and WHEY Rx, with PROTEIN Rx providing up to 3.5g of glutamine per serving.

The right supplements can make all the difference to your training

As a dietitian, Anèl often gets asked whether it’s necessary to take supplements. She believes that nutritional supplements can play an important role for people with active lifestyles or those preparing for events. They fill in nutrient gaps when diets fall short. Keep in mind, that they're meant to add to your diet, not replace the mix of diverse foods crucial for good health.

Here are a few other important supplements for swimmers:

Multivitamins and minerals

SPORT Rx Vitamin RX

Anèl highlights that intense training can weaken the immune system, making it vulnerable during and after workouts. This poses a risk for those training for events, as decreased immune function could lead to infections. While a healthy diet is key, supplements like multivitamins can be a helpful addition, providing extra nutrients as a boost or an 'insurance' policy against occasional dietary gaps.

“Athletes benefit from specific nutrients like B-vitamins, antioxidants (C and E), beta-carotene, selenium, and minerals (calcium, iron, zinc, magnesium). Despite maintaining a healthy diet, it's common to miss out on some of the 40+ essential nutrients needed daily,” she says.

Omega-3 fatty acids

After tough training sessions, your muscles are left riddled with microscopic tears; tears that, when healed, will make you stronger, bigger, and faster. Omega-3 fatty acids are powerful anti-inflammatory compounds that help to speed up recovery, thus making you stronger.

Because omega-3s effectively fight inflammation, they’re also useful at helping to prevent delayed onset muscle soreness (DOMS). Apart from speeding up exercise recovery, omega-3’s fend off injuries by preventing tissue degradation, easing inflammation, boosting blood and oxygen flow to muscles, increasing range of motion and relieving joint tenderness.

For a daily omega-3 intake of 1-3g, consider consuming fatty fish like mackerel or salmon 3-4 times a week. If quality fish is scarce or expensive, opt for a reliable omega-3 supplement. Check the EPA and DHA content on the label, aiming for a total of over 1000mg, typically requiring a dosage of 1000 to 2000mg of EPA + DHA. 


“Creatine is one of the most popular supplements among athletes, and unlike many of the supplements on the market, it has decades of evidence behind it and an excellent evidence base for its positive effects on sports performance and metabolism. Creatine is mostly found in the muscles as ‘free’ creatine or as phosphocreatine, where it has an essential role in powering exercise and movement,” says Anèl.

Creatine is normally found in meat and fish, but the most effective doses for swimmers and athletes are more than what you’ll find in normal foods. Therefore, supplementation is a good idea as it can increase the amount of high-energy phosphocreatine stored in the muscles and may improve performance and strength gains.

Creatine comes in various forms, but the most well-researched type is creatine monohydrate. Aim for 3-5g daily; no need for those hefty 20-30g "loading phases" – smaller doses work just as well, taking a bit more time to show results. Our CREATINE Rx has a convenient 5g per serving. Good news: creatine seems safe for overall health in recommended doses; just avoid going overboard.

Choosing the right supplements is crucial! Consider consulting with a sports-savvy registered dietitian for personalised advice and strategies tailored to your unique needs.

4 more nutrition tips for swimmers

In addition to the right supplements (as mentioned above), Anel has the following suggestions to help you feel your best before, during and after training.

Refuel your glycogen stores

Aquatic athletes who train daily and spend loads of time in the water often deplete stored carbohydrates (glycogen) during workouts. Beyond protein, carbohydrates play a pivotal role in recovery, not just for swimmers – but for all endurance athletes. Carbohydrates not only aid in muscle building and repair but also reduce muscle protein breakdown by stimulating insulin release.

“After exercising, it's important to eat the right kind of carbs to refuel your glycogen stores and start rebuilding your muscles,” says Anèl. Neglecting this aspect can compromise your future training performance. “After extreme endurance exercise, a swift replenishment strategy involves consuming 0.5-1g of high-glycaemic carbohydrates per 1 kg of body weight immediately after the workout. For instance, a 75kg individual would need 37-75g of carbohydrates, achievable through a sports recovery drink, chocolate milk, or snacks like jelly babies combined with biltong (ensuring a protein source for enhanced muscle glycogen storage),” she explains.

Carbohydrates also help support the immune system. Keeping enough glycogen before and after exercise can lessen disruptions in immune markers by reducing the body's stress hormone response to exercise.

Focus on rehydration and electrolyte balance

olympic swimmer erin in the water

Most swimmers will finish a training session or competition in some kind of fluid deficit, explains Anèl. “High-intensity exercise in the steamy environment of a heated indoor pool, or outdoors in the sun, can lead to moderate sweat losses, which are not obvious when the swimmer is already wet. If this deficit is not corrected it can have a significant impact on future training sessions.”

It’s therefore important to monitor the quantity and colour of your urine to assess hydration status. Urine colour should be clear (we don’t want apple juice!), and there should be a plentiful amount. To rectify fluid loss, aim to consume at least 240-360ml per 1kg sweat lost. Sweat loss is the difference in weight before and after exercise. Rule of thumb, aim for 300-500ml fluid directly after exercise to replace sweat. It’s also important to not over drink.

Anèl maintains that including electrolytes together with recovery fluid can assist in hydration and replacing sodium lost through excessive sweating. “Rather than just losing the fluid through excessive urination, the addition of electrolytes can help your body retain the water consumed,” she adds. 

To rehydrate effectively, take electrolytes with water following exercise. After extreme sessions, choose sports drinks that are scientifically formulated for recovery and provide electrolyte replacement.  Another alternative is consuming foods that contain sodium and potassium, such as bananas, biltong, citrus fruits and pretzels along with recovery fluids.

Support your immune system

Hard training may compromise your body’s immune system, and high levels of stress hormones reduce its ability to fight these infections. Many nutrition supplements, including glutamine, vitamin C and E, zinc, colostrum and probiotics, have all been touted to aid in the protection and support of the immune system.

The best strategies to support a healthy immune system include high-antioxidant foods e.g. fruits, vegetables, spices (turmeric and ginger), scheduling appropriate rest periods, and matching carbohydrate intake to your fuel needs. There is good evidence that carbohydrate intake during prolonged exercise reduces the release of stress hormones, explains Anèl.

Have blood tests done

Anèl says that nutrient deficiencies can manifest in various ways, like general feelings of fatigue, a drop in mood or motivation, susceptibility to illness, or a reduction in power output. But since any one of these could be caused by low levels of a range of nutrients, it’s hard to pinpoint quickly whether symptoms are because of a deficiency, or some other underlying cause like illness or infection.

If you can’t seem to shake your fatigue, blood testing can provide insights into health concerns that could affect your training and overall performance, like vitamin and mineral levels and overall nutrient status. It’s an ideal way to get a quick snapshot of your nutrient profile. Once you’ve identified any nutrients you’re low in, you can take steps to add these to your diet either through changes to the food you eat or using good-quality supplements.

For example, evidence suggests that vitamin D levels affect performance, muscle repair/recovery and risk of injury. Vitamin D also helps with calcium absorption, nerve signalling, immune function, blood pressure regulation, muscle strength and mass.

Other important nutrients that could impact training and performance are iron, magnesium and vitamin B12 levels. It’s therefore advisable to have your levels checked and if you have a deficiency, to correct it with supplements.