Most OCR athletes have heard of beetroot juice. Fewer have actually used it correctly. And almost none have gone deep enough into the research to understand why it works, when it doesn’t, and how to build a nitrate strategy that fits the specific demands of obstacle course racing.
This isn’t another generic “superfoods for athletes” article. The science behind dietary nitrates is specific, surprisingly robust, and directly applicable to the kind of mixed-intensity, multi-modal effort that OCR demands. If you’ve been ignoring this lever in your nutrition plan, it’s worth a second look.
What Dietary Nitrates Actually Do
When you eat nitrate-rich foods — beetroot, spinach, arugula, celery, chard — your body converts those nitrates through a two-step process. First, bacteria in your mouth convert nitrate (NO₃⁻) to nitrite (NO₂⁻). Then, in the lower gastrointestinal tract and various tissues, nitrite is converted to nitric oxide (NO). That final molecule, nitric oxide, is what does the work.
Nitric oxide is a potent vasodilator. It relaxes the smooth muscle lining of blood vessels, widening them and allowing more blood — and therefore more oxygen and fuel — to reach working muscles. But the performance benefit goes beyond blood flow. Research has identified a second mechanism: nitric oxide reduces the oxygen cost of mitochondrial ATP production. In plain language, your muscles become more fuel-efficient. They can do the same amount of work using less oxygen, which translates directly to improved endurance performance at submaximal intensities.
For an OCR athlete, that efficiency gain matters enormously. The running portions of a race — which constitute the majority of course distance — are largely submaximal aerobic work. A body that can sustain that effort at lower oxygen cost has more capacity left in reserve for the anaerobic spikes the obstacles demand.
What the Research Shows for Endurance Performance
The volume of peer-reviewed research on dietary nitrates and endurance performance has grown substantially over the past decade. Several key findings are relevant to OCR athletes.
Studies using moderate doses of beetroot juice — typically equivalent to around 300–500mg of inorganic nitrate — have consistently shown improvements in time-to-exhaustion at moderate intensities, reductions in VO2 at submaximal workloads, and small but measurable improvements in time-trial performance. Effects have been demonstrated in cycling, running, and rowing — all aerobic-dominant activities with direct parallels to the running and carry portions of an OCR course.
Perhaps more interesting for OCR specifically is research on nitrate supplementation and recovery between high-intensity efforts. Some studies suggest that elevated nitrate status supports faster phosphocreatine resynthesis after intense exercise — meaning your muscles recover more quickly between explosive efforts. On an OCR course where you might face a heavy carry, then run a kilometer, then hit a series of overhead obstacles, that faster recovery between anaerobic spikes could be meaningful.
There’s also evidence for reduced muscle soreness in the days following high-intensity exercise with nitrate loading, potentially related to nitric oxide’s anti-inflammatory effects on muscle tissue. For athletes who race multiple weekends in a season, that’s worth paying attention to.
The Practical Protocol
The research points to a few clear principles for making nitrates work in practice.
Timing matters. Peak blood nitrate levels occur roughly two to three hours after ingestion. For a race with a morning start, consuming a high-nitrate meal or concentrated beetroot shot the evening before and again two to three hours pre-race is the approach most consistent with the research. A single shot of concentrated beetroot juice taken the morning of, grabbed on the way to the start, is better than nothing — but it’s suboptimal.
Dose matters. Commercial beetroot shots vary considerably in nitrate content. Look for products that specify their nitrate content in milligrams — 300–400mg of inorganic nitrate appears to be the effective range in most studies. Whole beetroot juice in larger volumes can achieve similar doses, but requires more preparation and can cause GI issues in some athletes if taken in excess before a race.
Food sources work too. Athletes who consistently eat nitrate-rich vegetables — spinach, arugula, chard, beet greens, celery — throughout their training week maintain higher baseline plasma nitrate levels. The pre-race shot strategy works best as a top-up on an already-elevated baseline, not as a one-time hack on a background of low vegetable intake.
Don’t use antibacterial mouthwash. This one catches people off guard. The first step of nitrate conversion happens in your mouth, via the bacteria on your tongue. Antibacterial mouthwash kills those bacteria and dramatically reduces your ability to convert dietary nitrate into nitrite. Studies have shown that using antibacterial mouthwash before consuming beetroot juice essentially eliminates the ergogenic effect. If you’re going to use nitrates strategically, skip the mouthwash on race morning.
Where the Skepticism Is Warranted
The honest picture on nitrates is more nuanced than supplement marketers would have you believe. A few caveats deserve attention.
Most of the positive research has been done on recreational to moderately trained athletes. At the elite end of the athletic spectrum, several studies have shown smaller or non-significant benefits — possibly because highly trained athletes already have more efficient vascular systems, leaving less room for nitrate-driven improvement. If you’re competing at the elite or age-group elite level, the gains may be smaller than you’d hope. If you’re a competitive recreational athlete, the evidence is more encouraging.
Individual response also varies meaningfully. Some athletes show strong and consistent responses to nitrate loading; others see minimal effects. Genetic variation in nitric oxide synthase activity and gut microbiome composition both appear to influence how well an individual converts and utilizes dietary nitrates. There’s no way to know in advance whether you’re a responder without testing it in training — which is exactly where you should test it, not on race morning for the first time.
And while nitrates from whole food sources appear to be entirely safe, very high doses of concentrated beetroot products carry a small risk of GI distress in sensitive individuals. Start with lower doses in training to assess tolerance before committing to a pre-race loading protocol.
Building It Into Your Season
The smartest approach to dietary nitrates is not thinking of them as a race-week trick but as a nutrition habit with compound benefits. Building a diet that’s consistently high in leafy green vegetables and root vegetables gives you a baseline that makes the pre-race loading protocol more effective and contributes to day-to-day training quality.
For targeted use around race weekends, a simple protocol looks like this: increase nitrate-rich vegetable intake in the two to three days before a race, include a concentrated beetroot shot or high-nitrate meal the evening prior, and consume another dose two to three hours before the start. Avoid antibacterial mouthwash. Keep hydration consistent. That’s it.
There’s no magic here — just a well-supported physiological mechanism that most OCR athletes have left untapped. In a sport where margins matter and training hours are finite, the nutrition tools that are both evidence-backed and low-cost deserve serious attention.
Bottom line: Dietary nitrates aren’t hype — the research is real, the mechanism is understood, and the protocol is straightforward enough to implement without overhauling your entire nutrition plan. Add nitrate-rich foods consistently, time your pre-race loading correctly, and skip the mouthwash. It won’t carry you to a podium on its own, but if it buys you a few more minutes of efficient running on a long course, it was worth the beetroot stain on your kit.
Find the Gear
Shop performance nutrition products and nitrate supplements on Amazon.
- Beetroot Juice Shots for Athletes
- Dietary Nitrate Endurance Supplements
- Nitric Oxide Booster Sport Nutrition
- Organic Beetroot Powder Supplement
- Athletic Greens Powder with Spinach & Superfoods
Wall & Wire is an independent OCR media outlet. We may earn affiliate commissions from purchases made through the links in this article, but our recommendations are based on what actually performs on OCR courses.