Beetroot for marathon — the interest is in dietary nitrate, which converts to nitric oxide in the body. Nitric oxide relaxes blood vessels and may reduce the oxygen cost of running.
Over 42.2km, small improvements in running economy compound. A 1–2% reduction in oxygen cost can mean minutes off your finish time.
This article explains what the research shows and how to use beetroot as part of a marathon fueling strategy.
Beetroot for Marathon: The Short Answer
The research suggests that dietary nitrate from beetroot may improve running economy and time-to-exhaustion. For marathon runners, this means the same pace may feel slightly easier — or a faster pace may become sustainable.
It is not a replacement for training, carbohydrate fueling, or pacing. It is a supplement to those things.
What the Research Says
Running Economy
Lansley et al. (2011) studied trained runners and found that beetroot juice reduced oxygen cost during moderate-intensity running. Runners used less oxygen at the same pace.
For a marathon, this matters. Running economy is one of the strongest predictors of marathon performance.
What the Research Says
Running Economy
Lansley et al. (2011) studied trained runners and found that beetroot juice reduced oxygen cost during moderate-intensity running. Runners used less oxygen at the same pace.
For a marathon, this matters. Running economy is one of the strongest predictors of marathon performance.
Source: Lansley et al. (2011) — Journal of Applied Physiology
Time-to-Exhaustion
Bailey et al. (2009) found that dietary nitrate extended time-to-exhaustion by up to 16%.
This doesn't mean you'll run 16% faster. But the direction is consistent across studies.
Source: Bailey et al. (2009) — Journal of Applied Physiology
Individual Variation
Not all runners respond the same way. Baseline fitness, diet, and oral bacteria composition all influence the effect.
The only way to know if it works for you is to test it during training.
5 Key Fueling Strategies
1. Start Loading 5 Days Pre-Race
Begin the loading phase 5 days before race day. This builds baseline nitric oxide levels.
| Day | Dose |
| Day 1–3 | 1–2 tablespoons daily |
| Day 4–5 | 2 tablespoons daily |
Why? Consistent daily intake elevates baseline levels before the acute race-day dose.
2. Race Morning Dose: 2–3 Hours Pre-Start
Take 2–3 tablespoons of beetroot powder in 500ml water, 2–3 hours before the start.
Why? Peak plasma nitrite occurs 2–3 hours after ingestion. This is when the effect is strongest.
Important: Do not take it 30 minutes before the start. You'll miss the window.
3. Do Not Mix With Mouthwash
Mouthwash kills the oral bacteria that convert nitrate to nitrite. Skip mouthwash, tongue scraping, and breath mints during race week.
4. Test During Training First
Never try a new protocol on race day. Test it during a hard long run first. See how your stomach reacts. See if you notice a difference.
5. Use It With Your Normal Fueling
Beetroot does not replace gels, electrolytes, or carbohydrate loading. It works alongside them. Think of it as an additional layer — not a substitute.
Marathon Race Week Protocol
| Day | Dose | Notes |
| Monday | 1 tbsp | Morning |
| Tuesday | 1–2 tbsp | Morning |
| Wednesday | 2 tbsp | Morning |
| Thursday | 2 tbsp | Morning + evening |
| Friday | 2 tbsp | Morning + evening |
| Saturday | 1–2 tbsp | Morning only |
| Race Day | 2–3 tbsp | 2–3 hours pre-start |
Why reduce on Saturday? Maintains baseline without risking GI issues the day before the race.
Athlete Experiences
Individual reports. Not clinical evidence.
Omar Hassan — Danish Marathon Runner, 2:12:17 Copenhagen Marathon
"Stamox, taken daily throughout the camp, improved oxygen efficiency and sustained the engine when it mattered."
Yohan Zaradzki — Belgian Marathon Champion, 2:12 Marathon
"1 tbsp easy days. 2 tbsp threshold blocks. 3 tbsp long runs."
Common Mistakes
1. Testing It on Race Day
If you've never used beetroot before, race day is not the time to start. Test it during training.
2. Taking It Too Late
The effect peaks at 2–3 hours. Taking it 30 minutes pre-start misses the benefit.
3. Ignoring GI Sensitivity
Some runners experience stomach discomfort with concentrated beetroot juice. Powder mixed in water tends to be easier.
4. Expecting a Transformation
The effect is measurable but modest. It won't fix poor pacing or inadequate carbohydrate fueling.
Common Questions
How far before a marathon should I take beetroot?
2–3 hours before the start.
Should I load for multiple days?
Yes. 5 days of loading builds baseline nitric oxide levels.
Can I take beetroot during the marathon?
It's not practical mid-race. The benefit comes from pre-race loading and the acute dose.
Will it upset my stomach?
Some runners report mild GI sensitivity. Test it during training to see how you respond.
Related Reading
Beetroot loading protocol — the full race week plan.
Beetroot for runners — the 7-day protocol.
Best time to take beetroot powder — the 2–3 hour window.
Stamox Oxy-Plus — a beetroot powder used by athletes since 2007.
Stamox Oxy-Plus is a beetroot powder used by athletes since 2007. Measurable results. 12-week guarantee.
