Beetroot for people who train: nutrition and timing

Beetroot is one of the few vegetables with a real, measurable link to athletic performance, and it has nothing to do with vitamins. It comes down to nitrate, which means the benefit is narrower than the hype: a specific type of effort, a specific dose, a specific time window. Here are the numbers and a concrete schedule.

Nutrition facts

Per 100 g of cooked beetroot, roughly half a medium bulb or four thick slices:

• 44 kcal
• 10 g carbohydrate, about 8 g of it natural sugar
• 2 g fibre
• 1.7 g protein and 0.2 g fat
• 305 mg potassium, 80 mcg folate, 23 mg magnesium, 0.8 mg iron

Two things worth clearing up right away. Beetroot is not an iron source: that 0.8 mg per 100 g is plant iron your body absorbs poorly, so even half a kilo a day will not fix low ferritin. It is also not a fuel source: 200 g gives you about 20 g of carbohydrate, the same as one large banana, with far more fibre and volume.

What it does deliver is potassium and folate. A 200 g serving covers roughly 15% of daily potassium and around 40% of folate for just 88 kcal. As a side dish, that is a good trade.

Nitrate: the reason anyone talks about beetroot at all

Fresh beetroot contains roughly 200 to 300 mg of nitrate per 100 g, though soil conditions push the range anywhere from 100 to over 1,500 mg per kilogram. Bacteria on your tongue convert nitrate to nitrite, and your body converts nitrite to nitric oxide, which widens blood vessels and cuts oxygen cost at submaximal effort by about 3 to 5%.

In practice, that gives recreational athletes a 1 to 3% improvement in efforts lasting 5 to 30 minutes. On a 20-minute time trial that is 12 to 36 seconds. Not dramatic, but beetroot is one of very few ordinary foods where the effect shows up at all.

When to eat it

Before training

Blood nitrite peaks 2 to 3 hours after the meal. Eating beetroot 20 minutes before your warm-up does nothing except fill your stomach. If the session starts at 18:00, the beetroot goes with lunch around 15:00.

Loading over several days

A single dose works, but taking it 3 to 7 days in a row, once daily, gives a steadier effect. If you are targeting a race or a test, start a week out and take the final dose 2.5 hours before the start.

After training

No particular reason to. Post-session you want protein and carbohydrate, and beetroot supplies little of either. Eat it as a side if you like it, but do not count it as recovery.

How much, and in what form

The dose used in research is roughly 400 to 800 mg of nitrate. From whole beetroot that means 200 to 300 g. Below 100 g, do not expect any performance effect, though it is still perfectly good food.

• Raw and grated: retains the most nitrate. 150 g grated with a tablespoon of oil and some lemon is the most efficient version.
• Roasted or steamed: you lose about 10 to 20%. Roast 45 to 60 minutes at 200 °C, skin on.
• Boiled in water: 40 to 50% of the nitrate leaches into the water. Pour the water out and you pour out half the dose.
• Pickled from a jar: some nitrate survives, but it brings 300 to 600 mg of sodium per serving. A weaker everyday option.

One detail that genuinely kills the effect: antibacterial mouthwash. It wipes out the tongue bacteria that convert nitrate to nitrite and cancels most of the benefit. Skip antiseptic rinses for 2 hours either side of a beetroot meal.

Who this will not do much for

• Highly trained endurance athletes with a VO2max above 65: their nitric oxide production is already efficient and the effect often disappears entirely.
• Pure strength: on triples in the squat or deadlift with 3 to 5 minutes of rest between sets, there is essentially no difference.
• Hypertrophy: maybe one or two extra reps on sets of 15 to 20+, and inconsistently at that.

The clearest benefit is in intervals, team sports with repeated sprints, and efforts in the 5 to 30 minute range.

Side effects and confusing bits

In 10 to 15% of people, urine and stool turn reddish. That is the pigment betanin, not blood, and it clears within 24 to 48 hours.

Servings above 200 g cause bloating in sensitive people because of the fructans. Test your first large serving on an ordinary training day, never for the first time on race day.

The rule that applies to every food before competition: nothing new on the day.

The root holds about 150 mg of oxalate per 100 g and the leaves several times more, which only matters to a small group of people.

When to see a doctor

• If you take nitrates for angina or medication for erectile dysfunction: the combination can drop blood pressure too far.
• If you have had calcium oxalate kidney stones, ask how much oxalate per day you can handle.
• If you have chronic kidney disease or a potassium restriction.
• If red urine lasts more than 48 hours with no beetroot in your diet, or comes with pain and fatigue: get it checked.
• If you are on blood pressure medication and start feeling dizzy when standing up quickly.

The short version

• 200 to 300 g of beetroot gives 400 to 800 mg of nitrate, which is the dose that actually does something.
• Eat it 2 to 3 hours before training, ideally 3 to 7 days in a row.
• Raw or roasted, not boiled in water you throw away.
• No antibacterial mouthwash within 2 hours of the meal.
• Realistic gain is 1 to 3% on 5 to 30 minute efforts, and close to nothing on pure strength work.