Athletes know that what they eat before training directly impacts performance. But timing that meal or snack properly matters just as much, especially when it comes to nitric oxide foods.
Nitric oxide supports healthy circulation during exercise. It helps move oxygen and fuel to your muscles when you need it most. Many foods that drive this process are rich in dietary nitrates, and your body converts those nitrates into nitric oxide through a specific pathway that takes time to work.
But here’s the thing: if you eat these foods too close to training, the conversion hasn't finished, or if you do it too far out, you've missed the window entirely. Most athletes either don't know about this timing or they're guessing at it.
This guide ranks the top nitrate-rich foods on our list, explains how your body turns them into nitric oxide, and shows you exactly when to eat them for the best results.
Why Nitric Oxide Matters for Athletes
Dietary nitrates go through a two-step conversion in the body. Nitrates become nitrites. Nitrites become nitric oxide. That final molecule plays a key role in how muscles receive oxygen and fuel during exercise, which is why athletes across disciplines have started paying closer attention to what's on their plate.
Nitric oxide supports healthy circulation during exercise. Think of it as the system that moves fuel and oxygen to the places your body needs it most. The foods that are high in nitric oxide and drive this process share one thing in common: they are rich in dietary nitrates. The more nitrates you consume in the right window, the more raw material your body has to work with. And this becomes important because support for endurance and recovery starts here.
The Top Nitric Oxide Foods and Reviewed Nitrate Content
Among nitric oxide beets and leafy greens, nitrate content varies a lot from one food to the next. Some deliver a meaningful dose per serving, while others barely register. Here's how the top options actually stack up.
Red Spinach
Red spinach is notably the king of nitrate foods compared to other whole foods. That's based on nitrate research, which shows why it’s at the top of the ranking.
Part of what makes red spinach so nitrate-dense comes down to its biology. It belongs to the amaranthus family, and plants in this group naturally concentrate nitrates at a higher rate than common green spinach. So when you're looking for a food that genuinely supports nitric oxide pathways through food pathways, red spinach rules.
If you want a consistent, measured serving, red spinach extract and red spinach powder are the same, concentrated form.
Red spinach powder delivers a concentrated dose of dietary nitrate in a small serving. Research suggests 240 mg supports daily nitric oxide pathways, while 400 mg has been clinically studied for healthy circulation during exercise. The plant itself is naturally stimulant-free and any oxalates are scant, making it easier to use consistently without the side effects associated with some other nitrate sources. The potency is reliable because the extraction process concentrates the nitrates from the amaranthus leaves without adding caffeine or sugar.
Beetroot
Beetroot is the nitric oxide food that most athletes already know about. It's accessible and versatile, but labels often list mostly unknown nitrate levels. Beetroot juice has become a staple pre-training ritual for endurance athletes over the past decade, and it earned that spot for good reason. A cup of raw beets contains roughly 100 to 200 mg of nitrate, depending on the variety and growing conditions. That is a lot of beets.
Red spinach is 4-5x more nitrate-dense per serving, but beets remain a smart dietary choice as a workout recovery and for daily circulation support.
Other Foods That Contain Nitric Oxide
When we say “foods that contain nitric oxide,” we mean foods that support making it. Foods don’t contain nitric oxide. It’s a gas made in blood vessels. Nitrate makes nitric oxide. Several everyday foods that contain nitric oxide precursors are worth rotating into your diet, even if none match red spinach in natural concentration. Nitrate levels across these leafy vegetables have been well documented.
Arugula is one of the higher-nitrate leafy greens and works well in salads or smoothies. Celery is surprisingly high in nitrates and easy to juice or top with peanut butter, as a pre-training food. Radishes are an underrated source of dietary nitrate, especially when eaten raw. Kale and Swiss chard are solid contributors, too, though their nitrate levels shift with season and how you prepare them.
Think of these as supporting players. They're useful in a well-rounded diet, but they're not the ones carrying the heaviest load.
How to Time Nitric Oxide Foods Around Training
Timing is where many athletes leave value on the table. The nitrate-to-nitric-oxide conversion isn't instant. It takes roughly 60 minutes for the process to reach full activity after ingestion.
That means eating or taking a supplement about an hour before your session is the window most athletes find effective. Too close and the conversion hasn't finished. Several hours ahead, and the window closes before you start. If you're going the whole-food route, a nitrate-heavy pre-training plate works. But nitric oxide foods can be bulky–a lot, especially right before a hard session. Foods rich in nitric oxide precursors, in concentrated form, like red spinach powder, solve that problem without bulk.
Whole Foods vs. Red Spinach Extract
Both approaches have real value. The question is which path best fits your training lifestyle.
Whole foods give you fiber, micronutrients, and variety, and that's a great foundation for any athlete's diet. However, the nitrate content of whole foods varies. It varies with the season, the soil, and how long the produce sat in storage. You can eat a perfectly fresh beet and still get half the nitrates you expected.
The practical answer is to use both. Eat whole-nitric-oxide foods regularly as part of your everyday diet. Reach for red spinach powder when you need a precise, timed dose before training.
Make It a Habit
Nitric oxide foods aren't the kind of thing you add once and forget. They work because you do them consistently, session after session, week after week.
Red spinach leads in nitrate concentration. Beetroot and some greens round out the foundation. The real edge comes from understanding the timing, choosing the right form for your needs, and showing up with it regularly.
NyhutriGardens publishes ingredient science and educational research on this site to make nutrition science clearer and more accessible. Learn more at NutriGardens.com.
