8 Evidence-Based Supplements: What Actually Works for Athletes
Walk into any supplement store or scroll online, and it’s easy to feel like you’re missing out if you’re not taking the “latest” performance product. Powders, capsules, and drinks are often marketed as shortcuts to better strength, endurance, or recovery. In reality, only a handful of sports supplements are consistently supported by solid research.
As a sports dietitian, I always come back to the basics first: training, fueling enough, hydration, sleep, and recovery. Supplements don’t replace those foundations.
That said, in the right context, some supplements can support performance or recovery when used correctly. Let’s break down which supplements are actually worth considering, how they’re typically used, and what athletes should keep in mind before starting them.
Why Supplement Safety Matters
One of the biggest concerns with supplements isn’t whether they “work,” but whether they’re safe. Some products contain ingredients that aren’t listed on the label, are contaminated, or include substances that could cause a positive drug test.
For athletes, this matters whether you compete at a high level or simply care about your health. When supplements are used, they should:
Come from reputable brands
Be third-party tested (for example, NSF Certified for Sport or Informed Sport)
Have a clear purpose tied to training or performance
This is where working with a sports dietitian is helpful. Supplements should solve a specific problem, not just be added “just in case.”
Supplements With Strong Scientific Support
Below are supplements that consistently show benefits in research when they’re used for the right reasons and in the right amounts.
1. Creatine
What it helps with: Creatine supports short, intense efforts like sprinting, lifting weights, and repeated high-power movements. It can also help with strength gains over time.
What we know from research: Creatine is one of the most researched supplements in sports nutrition and is considered safe for most healthy athletes.
How it’s usually taken:
Optional loading phase: 20 g per day for 5–7 days
Ongoing dose: 3–5 g per day
Things to keep in mind: Some athletes notice a small increase in body weight due to water stored in the muscles. Not everyone responds the same way.
2. Beta-Alanine
What it helps with: Beta-alanine can help you push a little longer during hard efforts that last about 1–4 minutes, such as repeated sprints or high-intensity intervals.
What we know from research: Studies show small but meaningful performance improvements for certain types of high-intensity exercise.
How it’s usually taken:
4–6 g per day, split into smaller doses
Things to keep in mind: A tingling or “pins and needles” feeling is common and harmless.
3. Caffeine
What it helps with: Caffeine can improve endurance, focus, reaction time, and how hard exercise feels.
What we know from research: Caffeine has strong evidence across endurance sports, team sports, and strength training.
How it’s usually taken:
3–6 mg per kg of body weight
About 60 minutes before exercise
Things to keep in mind: Some athletes are more sensitive than others. Too much can increase anxiety, upset your stomach, or interfere with sleep.
4. Nitrates (Beetroot Juice)
What it helps with: Nitrates help your body use oxygen more efficiently, which can support endurance performance.
What we know from research: Beetroot juice has been shown to help some athletes, especially at recreational or sub-elite levels, and endurance long-distance athletes (like runners).
How it’s usually taken:
5–9 mmol of nitrate
Often around 500 mL of beetroot juice
Taken 2–3 hours before exercise
Things to keep in mind: Not everyone responds, and some people don’t tolerate the taste or volume well.
5. Protein Supplements
What they help with: Protein supports muscle repair and recovery after training.
What we know from research: Getting enough protein across the day supports training adaptations, especially with resistance exercise.
How it’s usually used:
Total daily intake: ~1.2–2.0 g/kg body weight
Supplements are helpful when food isn’t practical or appetite is low
Things to keep in mind: Most athletes can meet their needs through food. Protein shakes are a convenience tool, not a requirement.
6. Omega-3 Fatty Acids
What they help with: Omega-3s may support recovery and help manage muscle soreness.
What we know from research: Some evidence suggests benefits for muscle recovery and inflammation.
How they’re usually taken:
1,000–3,000 mg of EPA + DHA per day
Things to keep in mind: The ideal dose for athletes is still being studied.
7. Vitamin D
What it helps with: Vitamin D supports bone health, immune function, and muscle performance.
What we know from research: Low vitamin D levels are common, especially in athletes who train indoors or live in northern climates.
How it’s usually used:
Dosing should be based on blood work
Most recommendations are 1000-2000 IU per day
Things to keep in mind: More isn’t better. Too much vitamin D can be harmful.
8. Iron
What it helps with: Iron is essential for oxygen delivery and energy levels.
What we know from research: Supplementation improves performance only when iron levels are low.
How it’s usually taken:
Around 100 mg of elemental iron per day for deficiency (very important under medical guidance)
Things to keep in mind: Only take in case of deficiency to prevent iron overload. Iron should never be taken “just in case.”
Not sure which supplements (if any) make sense for you?
Book a free 15-minute discovery call to get personalized, evidence-based guidance. No more guesswork!
Final Words
Supplements can be helpful tools, but they’re not magic. If your training, fueling, and recovery aren’t dialed in, supplements won’t fix that. When used strategically, a small number of evidence-based supplements may support performance or recovery for certain athletes.
If you’re unsure whether a supplement is right for you, working with a registered sports dietitian can help you make informed, personalized choices that actually match your sport, training load, and health needs.
Hope this helped!
Maria Tanielian
Registered Dietitian/Nutritionniste
IOC Diploma in Sports Nutrition
ODNQ # 7223, CDBC # 2815, SDA # 949, CDO #16856
Studies Worth Reading With An Open Mind
Burke, L. (2017). Practical issues in evidence-based use of performance supplements: supplement interactions, repeated use and individual responses. Sports Medicine, 47(S1), 79-100. https://doi.org/10.1007/s40279-017-0687-1
Maughan, R. (2018). Infographic: helping athletes make decisions on dietary supplement use. British Journal of Sports Medicine, 52(23), 1492-1493. https://doi.org/10.1136/bjsports-2018-099510
Maughan, R., Burke, L., Dvořák, J., Larson‐Meyer, D., Peeling, P., Phillips, S., … & Engebretsen, L. (2018). Ioc consensus statement: dietary supplements and the high-performance athlete. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 104-125. https://doi.org/10.1123/ijsnem.2018-0020
Maughan, R., Shirreffs, S., & Vernec, A. (2018). Making decisions about supplement use. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 212-219. https://doi.org/10.1123/ijsnem.2018-0009
Schwenk, T. and Costley, C. (2002). When food becomes a drug: nonanabolic nutritional supplement use in athletes. The American Journal of Sports Medicine, 30(6), 907-916. https://doi.org/10.1177/03635465020300062701
International olympic committee expert group statement on dietary supplements in athletes. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 102-103. https://doi.org/10.1123/ijsnem.2018-0055
