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by Michele Tuttle

October 15, 2021

These four supplements have been extensively researched

Everyone knows someone who swears that taking or drinking this or that product makes him or her better, faster, and stronger. But does anything really work? And who can you trust when it comes to supplements because they’re outside the jurisdiction of any regulatory agency or reviewer? There are some effective supplements available out there, and some are illegal and dangerous.

All supplements should be viewed with caution, especially by athletes who view their performance as critical and who may be tested at events. Purity, effectiveness, and safety are essential. There are third-party consultants that attempt to certify supplements (e.g., NSF Certified for Sport) as safe for sports, but companies must voluntarily submit and pay to have their products reviewed, so many don’t.

Because individual response to supplements can vary, it’s important that athletes test supplements while training under race-like conditions to evaluate reactions and effects. Just because a supplement is sold and marketed for performance doesn’t mean that it will work for you.

Here are four of the best and safest performance-enhancing supplements for Masters swimmers.

Beetroot Juice/Nitrate

How it works. This well-researched supplement improves oxygen uptake during prolonged endurance events lasting longer than 12 minutes. Dietary nitrate—found in arugula, beetroot juice, celery, and spinach—enhances mitochondrial respiration and increases blood flow to muscles.

Dosage. The usual dose is approximately 300 to 500 milligrams two to three hours before an event, and may be more effective if repeated doses are taken for three or more days. Though eating nitrate from vegetables is highly beneficial and should be encouraged, many athletes rely on beetroot powder or nitrate supplements to ensure adequate dosage.

Potential side effects. Some of the side effects of dietary nitrate include lowered blood pressure, GI distress if sensitive to vegetable juices, urine coloration (pink or reddish).


How it works. The effects of caffeine on athletic performance are well-studied for short and long events. It lowers perceived exertion levels, increases endorphin release, enhances neuromuscular function, and improves vigilance and alertness. Caffeine is thought to improve performance by about 3% in activities lasting from five to 150 minutes.

Dosage. You should take about 3 to 6 milligram per kilogram of body weight (about 200 to 400 milligram for a 150-pound athlete) 60 minutes before an event or workout. An average 8 ounce cup of coffee has about 100 milligrams of caffeine. (Note: Most coffee mugs and take-away cups are larger than this.)

Potential side effects. Some of the side effects of caffeine intake include GI distress, heart arrhythmias, insomnia, and increased anxiety, especially at amounts higher than 9 milligrams per kilogram of body weight (more than 600 milligrams).

Beta Alanine

How it works. This amino acid is used by cells to produce carnosine, a muscle buffering agent that reduces the accumulation of hydrogen ions. Because hydrogen ions lead to muscle fatigue, higher levels of carnosine reduce muscular fatigue. Some studies show a 2% to 3% benefit for events lasting from 30 seconds to 10 minutes when using beta-alanine supplementation, though it may be less effective in well-trained athletes (0.2% to 1.3%).

Dosage. Typical dosing recommendations are about 65 milligrams per kilogram of body weight (4 grams per day for a 150-pound athlete) for a minimum of two to four weeks and up to 12 weeks. This is not a supplement that works immediately. Time-release formulas are available.

Potential side effects. Some of the side effects include itchiness and intermittent tingling (paresthesia).


How it works. This well-researched supplement increases muscle stores of creatine and leads to higher levels of phosphocreatine, a key compound for producing high-intensity muscular contraction. In addition, creatine may increase muscle mass and overall strength. Creatine may be most effective for improving performance (1% to 5%) for events lasting 30 to 150 seconds, such as resistance training, sprinting, or interval training. It may also have beneficial effects on endurance athletes through enhanced protein synthesis and glycogen storage.

Dosage. Creatine requires a loading phase of 20 grams per day for five to seven days followed by 5 grams per day indefinitely.

Side effects. Creatine has no known negative side effects when taken according to these recommendations. However, increased muscle mass may lead to an increase in body weight.


  • Health and Nutrition


  • Nutrition