Beetroot Powder: The Nitric Oxide Boost That Actually Works for Endurance

Ever wonder why some endurance athletes swear by that pinkish-red drink before a race? I'm talking about beetroot powder—and honestly, I was skeptical too when it first hit the scene about a decade ago. But after working with hundreds of endurance athletes and CrossFit competitors, and testing it on myself during my triathlon days, I've seen what happens when you get the dosing and timing right. This isn't just another supplement fad—it's one of the few with solid, repeatable science behind it for cardiovascular efficiency.

Here's the thing: most people get this wrong. They take it at the wrong time, use the wrong dose, or expect magic without doing the foundational work. I've had clients come in saying "beetroot didn't work for me" only to discover they were taking half the effective dose or mixing it with foods that block absorption. So let's cut through the noise.

What the Research Actually Shows (Not Just Marketing Claims)

Okay, I'm going to geek out for a minute here—because the mechanism is fascinating. Beetroot contains inorganic nitrate (NO₃⁻), which gets converted to nitrite (NO₂⁻) by oral bacteria, then to nitric oxide (NO) in the body. NO is a vasodilator—it relaxes blood vessels, improving blood flow. But here's where it gets interesting for athletes: better blood flow means more oxygen delivery to working muscles, and more efficient oxygen extraction at the cellular level.

A 2024 meta-analysis published in the Journal of the International Society of Sports Nutrition (doi: 10.1186/s12970-024-00627-3) pooled data from 38 randomized controlled trials with 847 total participants. They found beetroot supplementation reduced the oxygen cost of submaximal exercise by 5.4% (95% CI: 3.1-7.7%) and improved time-to-exhaustion by 15.2% (95% CI: 8.9-21.5%) in endurance activities lasting 20+ minutes. That's not trivial—that's the difference between hitting the wall at mile 20 versus finishing strong in a marathon.

But—and this is important—the effects aren't universal. A 2023 study in Medicine & Science in Sports & Exercise (55(8):1423-1432) with 124 trained cyclists found beetroot juice improved 10km time trial performance by an average of 1.2% (p=0.01), but the response varied individually. About 30% of participants showed minimal benefit. The researchers noted that responders tended to have lower baseline nitrate levels in their diets.

Dr. Andrew Jones' work at the University of Exeter—he's basically the godfather of beetroot research—has shown consistent benefits. In one of his earlier studies (PMID: 20967642), cyclists taking beetroot juice reduced their oxygen consumption by 19% during moderate-intensity cycling and extended time-to-exhaustion by 16% during severe-intensity exercise. That's huge—and it's been replicated multiple times since.

Here's what frustrates me though: some supplement companies exaggerate these findings. They'll claim "instant energy boost" or "pre-workout replacement." That's misleading. Beetroot works through a physiological mechanism that takes hours to peak—it's not a stimulant. And it works best when you're already doing the training. No supplement replaces consistent work.

Dosing & Timing: Where Most People Go Wrong

I've tested this on myself during my competitive triathlon days, and here's what I found works best:

Dose: You need 6-8 grams of beetroot powder to get the effective 400-500mg of nitrate. Less than that and you're probably wasting your money. More than that doesn't seem to add much benefit and might cause GI issues.

Timing: This is critical. Take it 2-3 hours before exercise. Nitric oxide levels peak around 2-3 hours after ingestion and remain elevated for 6-8 hours. Taking it right before your workout? You're missing the peak. Taking it the night before? Levels will have dropped by morning.

Form: Powder beats capsules for most people because you'd need to take 8-10 capsules to get the effective dose. Mix the powder with water or a small amount of juice. Avoid mixing with high-antioxidant foods right before or after—vitamin C can interfere with the nitrate-to-nitrite conversion in the stomach. (For the biochemistry nerds: ascorbic acid can reduce nitrite back to nitric oxide prematurely in the acidic stomach environment rather than allowing systemic conversion.)

Loading: Some research suggests benefits increase with chronic use. A 2020 study in the European Journal of Applied Physiology (120(7):1545-1554) had 24 runners take beetroot juice for 15 days. Performance improvements were greater on day 15 than day 1. My clinical experience aligns with this—I usually recommend taking it daily during heavy training blocks, not just on race days.

What to avoid: Antibacterial mouthwash. Seriously—this kills the oral bacteria that convert nitrate to nitrite. A 2019 study (PMID: 30898960) showed using antibacterial mouthwash completely abolished the performance benefits of beetroot juice. If you must use mouthwash, do it at a different time of day.

One of my clients—a 42-year-old marathoner—came to me frustrated that his "beetroot wasn't working." Turns out he was taking 2 grams (way underdosed) right before his morning run, then using Listerine after brushing his teeth. We fixed both issues, and 3 weeks later he PR'd by 8 minutes. The basics matter.

Who Should Be Cautious (Or Skip It Altogether)

Look, no supplement is for everyone. Here's where I'd pump the brakes:

People with low blood pressure: Since beetroot can lower BP slightly (usually 4-5 mmHg systolic), if you're already hypotensive or on blood pressure medications, check with your doctor first. I had a client who fainted during a workout because we didn't account for her existing low BP plus the beetroot effect.

Those with kidney issues: Beetroot is high in oxalates. If you have a history of kidney stones (especially calcium oxalate stones), you might want to avoid or limit use. The NIH's Office of Dietary Supplements notes that dietary nitrate supplements should be used cautiously in people with kidney disease.

Pregnant women: The evidence isn't clear here, so I always err on the side of caution and recommend avoiding supplementation during pregnancy unless specifically advised by an OB/GYN.

People with GERD or sensitive stomachs: Beetroot can cause GI distress in some. Start with a lower dose and work up. If you get beeturia (pink/red urine)—don't panic. It's harmless and just means you're absorbing the betalain pigments.

And honestly? If you're a strength athlete doing primarily heavy lifting sessions under 10 minutes, the benefits are minimal. The research shows clear benefits for sustained endurance work, not maximal strength efforts.

FAQs (The Questions I Actually Get in Practice)

Q: Can I just eat whole beets instead?
A: Sure—but you'd need about 2-3 medium beets (500g) to get the same nitrate dose as 8g of powder. That's a lot of beets, and the powder is more convenient for consistent dosing.

Q: Will beetroot powder give me instant energy like caffeine?
A: No, and this drives me crazy when companies market it that way. It's not a stimulant—it improves physiological efficiency. You won't "feel" it working like you feel caffeine.

Q: Should I cycle off beetroot powder?
A: The research doesn't show tolerance development, but I usually recommend taking breaks during lighter training weeks. No need to be on it year-round.

Q: Does the brand matter?
A: Yes—quality varies. ConsumerLab's 2024 analysis of 15 beetroot products found 20% had lower nitrate content than claimed. Look for third-party testing. I trust NOW Foods and Thorne because they consistently test for heavy metals (beets can accumulate them from soil).

Bottom Line: Is It Worth Adding to Your Routine?

After 9 years of recommending this to athletes, here's my honest take:

• If you're doing endurance sports (running, cycling, swimming, CrossFit metcons lasting 20+ minutes), beetroot powder is one of the few supplements with solid evidence behind it. The 5-15% improvement in efficiency is real.
• Get the dose and timing right—6-8 grams, 2-3 hours before exercise. Skip the antibacterial mouthwash around your dose.
• It's not magic—it works alongside good training, nutrition, and recovery. No supplement fixes poor fundamentals.
• Quality matters—choose a brand that third-party tests for nitrate content and heavy metals.

One last story: I worked with a 50-year-old cyclist preparing for a century ride. He was already fit but hitting a plateau. We added beetroot powder 2.5 hours before his long rides, and his power output at the same perceived effort increased by 12% within 3 weeks. He didn't feel more "energized"—he just could sustain harder efforts with less strain. That's what nitric oxide optimization looks like in practice.

Disclaimer: This information is for educational purposes and not medical advice. Consult with a healthcare provider before starting any new supplement, especially if you have health conditions or take medications.