Top Ten Supplements for Endurance Athletes
Endurance athletes often seek dietary supplements to enhance performance, delay fatigue, and expedite recovery. There are some general guidelines when considering supplements
Suitability: Supplements can be divided into health (H) and performance (P) supplements. Performance supplements are recommended for the more experienced, competitive athletes, while all athletes can consider health-related supplements.
Periodisation: Taking performance supplements needs to be periodised, just like training, racing and nutrition. A qualified sports dietitian/nutritionist can help with this.
Individual Variability: Supplement responses vary based on genetics, diet, and training status. It's recommended to trial supplements in training well before competition.
Quality Assurance: Choose supplements that have been third-party tested to ensure purity and avoid inadvertent ingestion of prohibited substances.
Regulatory Compliance: To avoid violations, ensure that any supplement complies with the regulations of your sport's governing body.
Health Status: Consult with a healthcare professional or a registered sports dietitian before beginning any supplementation regimen, especially if you have underlying health conditions or are taking medications.
While certain supplements have demonstrated benefits, they are intended to complement, not replace, a well-structured training program and a balanced diet. Individual experimentation and professional guidance are key to optimising performance safely and effectively.
Among the myriad options, certain supplements stand out due to robust scientific backing. This article provides a comprehensive guide to 10 science-supported supplements, including recommended dosages.
1. Caffeine (P)
Caffeine is a well-established ergogenic aid known to enhance endurance performance by stimulating the central nervous system, reducing perceived effort, increase fat metabolism and increasing alertness. It has been shown to improve both aerobic and anaerobic performance.
Recommended Dosage: A typical effective dose ranges from 1.5 to 3 mg per kilogram of body weight, consumed approximately 30 to 60 minutes before exercise. For a 70 kg individual, this equates to 105-210 mg of caffeine. Starting at the lower end is advisable to assess tolerance and minimise potential side effects such as jitteriness or gastrointestinal discomfort. One cup of coffee generally contains 60-100 mg of caffeine, depending on the method of preparation. A standard can (250 ml) of Red Bull contains 80 mg of caffeine and a standard can of Coca-Cola (355 ml) 34 mg. Over-the-counter caffeine tablets usually contain 100 or 200 mg of caffeine. The stimulating effects of caffeine usually last between three and six hours, depending on if you are a fast or a slow metaboliser. For Ironman athletes, 200-300 mg 1 hr before the start and a similar dose halfway through the bike should be sufficient, especially when you can top up during the run with coke.
Suitability: Competitive and age-group athletes.
Periodisation: Before and during endurance events.
2. Buffers (P)
Sodium bicarbonate acts as a buffering agent, neutralising the accumulation of hydrogen ions during high-intensity exercise, thereby delaying muscle fatigue. Recent formulations have mitigated previous gastrointestinal issues associated with their use.
Another buffering agent is beta-alanine, an amino acid that increases muscle carnosine levels. This enhances the muscle’s ability to buffer acid during high-intensity exercise, improving performance and delaying fatigue.
Recommended Dosage: The typical dosage for bicarbonate is 0.2 to 0.4 grams per kilogram of body weight, ingested 60 to 90 minutes before exercise. For a 70 kg athlete, this amounts to 14–28 grams. Due to potential gastrointestinal discomfort, starting with a lower dose is recommended. Consider using formulations designed to reduce side effects, even if they are significantly more expensive.
The effective dose for beta-alanine ranges from 2 to 6 grams per day, and it is taken in divided doses to minimise the risk of paraesthesia (a tingling sensation). Consistent supplementation over several weeks is necessary to elevate muscle carnosine levels effectively.
Suitability: Elite athletes.
Periodisation: During the competition season before targeted events.
3. Iron1
Overview: Iron is a vital mineral essential for producing haemoglobin and myoglobin, proteins responsible for transporting oxygen in the blood and muscles. Sufficient iron helps prevent fatigue and supports sustained energy during endurance events. Adequate iron levels are crucial for endurance athletes to maintain energy levels and overall performance. Iron supplementation is a must for iron-deficient athletes. A blood test is the only way to assess your iron status and is strongly recommended before taking iron. There is debate among medical professionals and scientists about what is the optimal iron level for endurance athletes. Serum ferritin measures our iron stores and is the most accurate indication of iron deficiency. However, inflammatory conditions can affect the reading (falsely elevated). This includes illness and immediate post-hard training. A doctor must order and assess iron studies in conjunction with haemoglobin and Haematocrit.
Recommended dosage: Following recommended dosages and consult with a healthcare provider before starting supplementation is essential. The appropriate dosage varies based on individual needs and should be guided by medical advice to minimise potential side effects like constipation and nausea. Iron supplements are better absorbed by the gut in the presence of vitamin C, either by taking it with food containing vitamin C or with a vitamin C supplement. Incorporating iron-rich foods such as red meat, poultry, seafood, beans, lentils, tofu, spinach, and fortified cereals can help maintain adequate iron levels.
Periodisation: when indicated, in consultation with your medical provider. Athletes doing altitude training are recommended to take iron even if their iron stores are healthy. At altitude, the oxygen processing systems are under pressure, and more iron is used in the process, so keeping stores well supplied is a way to prevent problems and help adaptation.
Suitability: All athletes
Note: Endurance athletes, especially females and those engaged in high-impact activities like running, may be at increased risk of iron deficiency due to factors like foot-strike haemolysis (breakdown of red blood cells) and dietary restrictions. Regular monitoring and a balanced diet are key to preventing deficiencies.
4. Electrolytes, including sodium (H and P)
Sodium is a vital electrolyte crucial in maintaining fluid balance, nerve function, and muscle contractions. Typically, the Western world's intake of dietary sodium (through salt) is high. However, in some situations, such as prolonged training and racing in the heat, such as Ironman triathlons, sodium intake is essential to sustain performance and prevent issues such as hyponatremia (low blood sodium) or muscle cramps.
Recommended Dosage: During Exercise: Athletes are advised to consume between 300 and 600 milligrams of sodium per hour during prolonged endurance activities in hot conditions. This supplementation helps offset sodium losses through sweat and supports optimal physiological function. This is a wide range as it depends on individual sweat rates and environmental conditions. Individual needs can be determined through sweat testing or in consultation with a sports dietitian or nutritionist. Most sports drinks contain sodium which promotes absorption of fluid from the gut. In hot conditions, salt tablets can be supplemented. Sodium supplementation should be part of a comprehensive hydration plan that includes adequate fluid intake to maintain performance and prevent dehydration.
Suitability: All athletes.
Periodisation: Use for any training and racing over 90 minutes.
5. Nitrates (P)
Dietary nitrates, commonly found in beetroot juice, enhance nitric oxide availability, improve blood flow, reduce oxygen cost during exercise, and potentially enhance endurance performance.
Recommended Dosage: A typical regimen involves consuming 300–600mg of nitrate (equivalent to approximately 500 ml of beetroot juice) 2 to 3 hours before exercise. Chronic loading protocols may involve daily consumption for several days before an event.
Suitability: Elite athletes.
Periodisation: Before targeted events.
6. Creatine (P)
While traditionally associated with strength and power athletes, creatine supplementation can benefit endurance athletes by enhancing recovery and glycogen storage (when taken with carbohydrates) and potentially improving performance in high-intensity bursts during prolonged events.
Recommended Dosage: A common approach is a loading phase of 20 grams per day, divided into four daily doses for 5–7 days, followed by a maintenance dose of 3–5 grams daily. Alternatively, a daily intake of 3–5 grams without a loading phase can also increase muscle creatine stores over time.
Suitability: Elite and competitive age group athletes
Periodisation: Intermittently or continuously throughout the year.
7. Protein, including Branched-Chain Amino Acids (BCAAs) and whey protein (H and P)
BCAAs, comprising leucine, isoleucine, and valine, may reduce muscle soreness and mental fatigue during endurance exercise, although evidence on performance enhancement is mixed. Whey protein accelerates recovery when taken straight after training and competition.
Recommended Dosage: Intakes of 5–10 grams BCAA’s before or during exercise are commonly used. A dose of 20-30 grams whey protein immediately post exercise optimises muscle recovery. BCAA’s are found in common foods such as beef, chicken, fish, eggs, milk, whey and soy
Suitability: All athletes who train a lot.
Periodisation: During periods of heavy training and racing.
8. Vitamin D (H and P)
Vitamin D is crucial for bone health, muscle function, and immune support. Deficiency can lead to increased injury risk and impaired performance. Endurance athletes, especially those training indoors or in regions with limited sunlight, may be at higher risk for deficiency.
Recommended Dosage: General guidelines suggest a daily intake of 600–800 IU for adults. However, athletes may require higher doses to maintain optimal serum levels. Some studies recommend 1,500–2,000 IU per day, particularly for those with limited sun exposure. In cases of deficiency, higher doses (up to 4,000–5,000 IU daily) may be prescribed under medical supervision.
Suitability: All athletes, especially during the winter months and depending on blood levels.
Periodisation: During the winter months.
9. Omega-3 Fish Oil (H and P))
Omega-3 fatty acids, particularly EPA and DHA, possess anti-inflammatory properties that can aid in recovery, reduce muscle soreness, and enhance cardiovascular health. They may also improve endurance capacity by increasing oxygen delivery to muscles.
Recommended Dosage: A daily intake of 250–500 mg of combined EPA and DHA is recommended for general health. Athletes may benefit from higher doses:
· Recreational Athletes: 1–2 grams (1,000–2,000 mg) per day.
· Competitive Athletes: 2–4 grams (2,000–4,000 mg) per day.
Suitability: All athletes.
Periodisation: Daily.
10) Ketones (P)
Ketone supplements have garnered attention in endurance sports due to their potential to enhance performance and recovery. The effectiveness of ketone supplements in improving athletic performance remains a topic of ongoing research. Some studies suggest potential benefits, such as enhanced endurance and improved recovery, while others have found minimal or no impact. For instance, research indicates that while ketone supplements can elevate blood ketone levels, their direct effect on performance is inconsistent. It has become a popular supplement in professional cycling pelotons.
Recommended Dosage: Due to varying formulations and individual responses, there is no universally established dosage for ketone supplements. However, studies have administered doses ranging from 0.3 to 0.5 grams per kilogram of body weight. Always follow the manufacturer’s guidelines or doctor’s recommendation. One downside is they are very expensive. Reported side effects include nausea and diarrhoea.
Suitability: Elite athletes.
Periodisation: Daily during heavy training and racing periods or before targeted races.
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Notes from Gordo: John and I will be taking a deeper dive on Iron in a future article.
In the next edition of Gordo’s Guide to Going Long, I will be sharing what I actually do (and have actually done) with regard to John’s Top Ten List.
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