3 Supplements for Triathletes (and 6 More That You Should Consider)

Caffeine is well-known to be a performance booster for endurance events. The biggest benefit that people notice is that it reduces the rate of perceived effort. It makes things feel easier.

But more importantly, it can improve your record times. A meta-analysis that included the majority of the research on caffeine and endurance performance highlighted that it improved performance by an average of 2.2%.

Reducing your triathlon time by 1-3% is a pretty big deal for something as simple as consuming caffeine, and most people are willing to put in a lot more work for fewer results.  

From another perspective, caffeine is a gastrointestinal stimulant. This is not relevant for everybody. But if it causes any gastrointestinal distress that noticeably impacts your performance, it is worthwhile weighing up the pros and cons. If that gastrointestinal distress impacts your performance negatively, it could outweigh the 1-3% boost caffeine provides. 

Dosage: 1-3mg/kg of body weight, 30 minutes before the race. Going up to as high as 6mg/kg can be an option as well.  

One of the more recent supplements that have burst onto the radar of triathletes looking to improve their performance is beetroot juice. The way beetroot juice works is through the effects of nitrates.  

Nitrates are typically found in vegetables and they mainly act by vasodilation and improved blood flow. This results in increased efficiency and improved time to exhaustion.

In terms of performance, this improved blood flow translates to an average reduction in race times of around the 1.5% mark.

Dosage:  5-7mmol of nitrate around 3hrs before training.  

The effects typically take 30 minutes to be noticeable, peak after 90 minutes, and last for 6-8hrs.

It is also worth noting that taking beetroot juice daily for 3-4 days improves its effectiveness even more than acute dosage, so arguably it would make sense to do that instead of just a once-off dose. The effects seem to plateau after about 6 days. 

The final thing to be aware of is that you must not brush your teeth or use mouthwash right after taking beetroot juice as it can block the conversion of nitrates into nitrites, which also blocks the effectiveness of the supplement.  

For any event over >60 minutes, it is worthwhile taking on carbohydrates during the race. A large part of this is because glycogen depletion leads to a significant reduction in performance.  

Since glycogen is the storage form of carbohydrates, taking on easily digestible/absorbable forms of carbohydrates can improve performance.  

Gels and sports drinks that involve multiple forms of carbohydrate, such as glucose or maltodextrin and fructose, allow you to consume more total carbohydrate without gastrointestinal distress.  

Realistically, the higher you can get this carb consumption intra-race before experiencing negative symptoms, the better. Gels and sports drinks are designed to allow you to efficiently take on higher amounts of carbohydrates to improve your performance.  

In addition to that, they will often come alongside electrolytes in the ideal ratio for your body during exercise.  

Dosage:  30-90g of carbs per hour. Start at the lower end and build up to whatever level you can tolerate.  

Protein powder certainly is not necessary, but it can be a helpful tool for meeting your protein needs. You can meet your protein needs 100% through food, and do not need to supplement.  

Triathletes do not typically need as high a total protein target for the day as people in sports like bodybuilding or powerlifting, but it is still important to consume enough protein.  

Protein powder can be a convenient way to increase your protein intake. It can also be useful if you want to consume protein post-workout but do not have the appetite to eat a solid meal.  

Dosage: 0-60g per day, as needed based on total needs and daily intake through food.

Vitamin D is a supplement that can help a super long list of things. The caveat to that though, is that it is typically beneficial if your blood levels are deficient or on the low-end of the healthy range.  

If you already have a good level of vitamin D in your blood, there likely will not be any additional benefit. Low vitamin D status impacts bone health, immunity and in some cases can impact strength and balance.

These things likely do not directly impact endurance performance in the short term but can play a role over long term development. If you train for long hours outdoors, like a lot of triathletes do, you are less likely to have low vitamin D than the average person. But it can still be worth getting a blood test just to check.

Dosage: 1000IU per day is the standard dosage, but higher dosages can be recommended if looking to quickly address a deficiency.

Beta-Alanine is more commonly thought of for slightly shorter and more intense activities, but it can still have applications for triathletes. It can help reduce muscle fatigue and improve time to exhaustion.  

While there still is not a lot of research on it for longer forms of activity, there is evidence that beta-alanine can improve time for a 10km runs. It also can aid aid in the final sprint at the end of a race, which can make a difference in overall outcomes.

Dosage: 4-6g per day (split over multiple dosages if necessary, to avoid paraesthesia)

While research is mixed on the benefits of omega 3’s for endurance athletes, there can be potential benefits. And the likelihood of these potential benefits improves even more for people who have inadequate intakes of fish or omega 3’s in their diet at the baseline before starting supplementation.

The main benefit is that DHA and EPA, which are found in fish oil, can play a role in reducing inflammation.This can help improve recovery and potentially be beneficial from an injury perspective.  

Omega 3’s can also help with vasodilation, which can help promote improved blood flow like beetroot juice does.

Dosage: 1g per day (although certain situations can warrant higher dosages).

Triathletes have higher iron requirements than the average person due to the high volume of training required. This increases the number of red blood cells which increases the physiological demand for iron.  

Low iron status can result in feeling fatigued which is going to impact your ability to train to your full potential. It can also result in a poor appetite and increased frequency/duration of illness, which could translate to worse training and performance.  

Once again though, this is a supplement that is only worthwhile if you have low iron. If your iron status is already optimal, adding a supplement could not potentially be detrimental.

Dosage: Based on doctors’ recommendations to address deficiency if relevant.  

Probiotics can help improve immunity in terms of reducing the frequency, severity, and duration of illness. This is particularly relevant for times of travel or relatively intense phases of training. By having more time being healthy and well, it can result in improved training over a year.

Dosage: 5-10 billion colony forming units per day of a product that is high in species of Bifidobacterium and Lactobacillus.