Beet is rich in nitrate. Your body turns nitrate into nitric oxide, which helps open up blood vessels and move more blood and oxygen to working muscles. This can make hard efforts feel a little easier and may help you hold pace longer.
Aim for about 500 mg of nitrate per serving. That usually comes from roughly 3–6 g of beet powder. Start on the low end to check your stomach tolerance.
Take it 2–3 hours before training so nitrate has time to turn into nitric oxide. For big events, some athletes load daily for 3–6 days and still take a pre-event serving.
Pairs well with citrulline or L-citrulline. You can also take it with carbs or caffeine if those are part of your routine.
Nitrate content varies a lot between products. Pick one that lists the nitrate amount on the label.