Fueling the Long Game: 5 Key Supplements Every Triathlete Should Know

Hi there! My name is Rebekah and I am a sports dietitian living in Ottawa, Ontario. As I have been working with triathletes prepping for their summer race season here in Canada (and training for a few triathlons myself), I often get questions about various sports nutrition supplements and their uses in training and competition. Although I believe in a food-first approach, once diet has been optimized, sports nutrition supplements can certainly offer an additional benefit. So let's get into it!

Triathlon training demands endurance, strength, and mental grit. Nutrition is a major piece of the performance puzzle, and while nothing beats a solid diet, certain supplements can give triathletes a legal, research-backed edge. Here’s a look at five of the most well-studied sports supplements—creatine monohydrate, caffeine, sodium bicarbonate, nitrate (often from beetroot), and beta-alanine—their benefits, and a few caveats to keep in mind.

1. Creatine Monohydrate

Why it helps: While creatine is best known for its role in strength and power sports, it has surprising benefits for triathletes, particularly in sprinting and recovery. It increases phosphocreatine stores in muscles, helping regenerate ATP (your muscles' energy currency) faster during high-intensity bursts.

Pros:

• Improves sprint performance and repeated high-intensity efforts.

• May aid recovery and lean muscle maintenance during intense training blocks.

Cons:

• May cause mild weight gain due to water retention—less ideal during long races.

• Some gastrointestinal discomfort for sensitive individuals.

2. Caffeine

Why it helps: Caffeine is a go-to performance enhancer for endurance athletes. It lowers perceived exertion, increases alertness, and can enhance endurance by helping your body mobilize fat stores for energy.

Pros:

• Increases focus and stamina during long races or training sessions.

• Easy to dose and fast-acting (peak effect usually within an hour).

Cons:

• Can cause jitters, GI upset, or sleep disruption if taken too late in the day.

• Not everyone responds equally—some athletes are “non-responders.”

3. Sodium Bicarbonate

Why it helps: This is a buffering agent that helps delay fatigue during high-intensity efforts by neutralizing acid buildup in muscles. Especially useful in events with bursts of anaerobic effort—think hill climbs or final kicks.

Pros:

• May improve performance in short, intense intervals or during the end stages of a race.

• Can be combined with other supplements for synergistic effects.

Cons:

• Known to cause bloating or GI distress; trial and error needed with dosing.

• Works best in events lasting 1–10 minutes, less so for long steady-state efforts.

4. Nitrate (Beetroot Juice)

Why it helps: Dietary nitrate, often consumed via beetroot juice, boosts nitric oxide production, which improves blood flow and reduces the oxygen cost of exercise.

Pros:

• Enhances endurance and time-to-exhaustion.

• May reduce blood pressure and support cardiovascular health.

Cons:

• Effects can vary; some athletes see little benefit.

• Can cause pink urine or stools (harmless but surprising).

5. Beta-Alanine

Why it helps: Beta-alanine raises muscle carnosine levels, which buffer acid in muscles during high-intensity exercise. This helps delay the "burn" and extend peak effort capacity.

Pros:

• Ideal for sprint finishes and interval training.

• Builds up with daily supplementation—long-term benefit.

Cons:

• Causes tingling (paresthesia) in some people.

• Requires a loading phase of several weeks for full effect.

Final Thoughts

Not all supplements are created equal, and none are a magic bullet. But with smart integration into your routine—alongside proper training and diet—these five can give triathletes a real edge. Always test supplements in training well before race day, and consider working with a sports dietitian to dial in the right plan and learn about safe dosages for your body and goals.

If you are training for a triathlon this summer, consider joining my Nutrition for Long-Distance Triathlon course starting May 16th, 2025. This course runs for 4 weeks and will provide you with the ins and outs of nutrition for triathlon training and competition.

Connect with me to learn more or click here to register! Space is limited.

Talk soon!