How Pre-Training Dietary Nitrate From Swiss Chard and Beetroot Greens Can Improve Endurance Economy, Blood Flow, and Repeated-Set Performance
Use nitrate-rich greens before training to reduce oxygen cost, support blood flow, and improve repeated efforts. Here’s the dose, timing, and practical plan.
If you’ve ever felt a little more efficient on a day you had beets or beet greens before training, that is not random. In controlled studies, dietary nitrate can lower the oxygen cost of submaximal exercise and improve performance in tasks that depend on repeated high-force or high-velocity efforts (Bailey et al., 2009; Lansley et al., 2011). The same mechanism can matter for hybrid athletes who need better endurance economy and less fade across repeated sets.
What dietary nitrate actually does
Dietary nitrate is converted to nitrite by oral bacteria and then to nitric oxide, especially when oxygen availability is limited or muscle acidity rises during hard work. Nitric oxide improves vasodilation, supports blood flow distribution, and appears to reduce the ATP cost of force production in skeletal muscle (Lundberg et al., 2008; Jones, 2014). The practical result: you may need less oxygen at a given pace or load, and you may recover a bit better between bouts.
This is why nitrate is different from generic “pump” supplements. It is not just about acute vasodilation. It changes how efficiently muscle uses oxygen and may improve contractile efficiency at the level of the muscle fiber and mitochondria (Jones, 2014). That is why endurance athletes, rowers, cyclists, runners, and mixed-modal lifters all have reason to care.
Why Swiss chard and beetroot greens matter
Most people know beetroot juice. Fewer know that beet greens and Swiss chard are also nitrate-dense. In practice, leafy greens can give you a meaningful nitrate dose without relying on processed shots or juice. Nitrate content varies by soil, season, and storage, but these foods can contribute materially to intake, especially if you use a large serving before training.
For performance purposes, the target is the nitrate, not the color. A high-nitrate meal built around Swiss chard, beet greens, or a concentrated beet product can support the same pathway if the dose is high enough and the timing is right (McMahon et al., 2017).
What the evidence says about performance
The best-supported benefits are in submaximal endurance performance and repeated high-intensity efforts. In a foundational trial, beetroot juice reduced the oxygen cost of submaximal cycling and improved time-trial performance (Bailey et al., 2009). Later work showed that nitrate can improve running economy and endurance performance, especially in less-trained individuals and in tasks where efficiency matters (Lansley et al., 2011; Jones, 2014).
For strength athletes, the story is more selective. Nitrate does not reliably increase maximal one-rep strength, but it can help with repeated-set performance, power maintenance, and fatigue resistance during clustered or high-rep work. That matters if your session includes multiple sets of squats, pulling, sled work, intervals, or mixed conditioning blocks. Some studies show enhanced muscle contractile efficiency and improved performance in repeated sprint or high-intensity protocols, although response is variable (Wylie et al., 2013; McMahon et al., 2017).
The key point: if your training outcome depends on sustaining output, nitrate is more likely to help than if your session is a single maximal lift.
Best dose and timing
The most practical performance range is 5 to 9 mmol of nitrate, taken about 2 to 3 hours before exercise. That is the window used in many successful trials and aligns with the time required for nitrate-to-nitrite conversion and peak circulating nitrite (Wylie et al., 2013; Jones, 2014).
Here is the working protocol:
- Target dose: 5–9 mmol nitrate pre-training
- Timing: 2–3 hours before the session
- Form: beetroot juice, concentrated beet shot, or a nitrate-rich whole-food meal using beet greens/Swiss chard
- Frequency: use on key sessions, not necessarily every day
Whole foods make exact dosing harder. That is fine if you are using them as part of a consistent routine. If the goal is precision, nitrate-standardized products are easier to control. If the goal is a food-based approach, you need a large serving and you should keep the rest of the pre-workout meal simple.
A practical food-based approach:
- 2–3 large cups cooked Swiss chard or beet greens
- 1 medium beetroot added if tolerated
- A carb source such as rice, potatoes, or bread
- Low-fat, low-fiber add-ons if the session is intense and gut comfort matters
This will not always match a standardized 6–8 mmol dose, but it can get you into the relevant range depending on produce nitrate content.
How to preserve the effect
The nitric oxide pathway depends on oral bacteria. Strong antibacterial mouthwash and aggressive tongue-scraping can blunt nitrate reduction to nitrite and may reduce the performance benefit (Govoni et al., 2008; Kapil et al., 2013). If you are using nitrate for training, do not sanitize your mouth right before dosing.
That means:
- Skip antiseptic mouthwash on nitrate days
- Do not take nitrate immediately after brushing with harsh antibacterial rinse
- Keep the dose consistent for several sessions before judging response
You also need enough carbohydrate and fluid for the session itself. Nitrate is not a substitute for fuel. It can improve efficiency, but it will not rescue a glycogen-depleted athlete doing a high-volume workout.
Who is most likely to benefit
The strongest responders tend to be athletes and trainees doing:
- 20 to 60 minute endurance efforts
- Repeated sprints or intervals
- High-rep resistance sessions with short rest
- Mixed-modality training where pace preservation matters
In already highly trained athletes, the effect is often smaller and more inconsistent. That does not mean it is useless; it means you should judge it on your own data. If your interval pace, rep quality, or session RPE improves across multiple trials, keep it. If nothing changes, do not force it.
A serious food-first protocol
If you want a food-based nitrate session without guessing, use this setup:
2–3 hours pre-training
- 1 large bowl of cooked Swiss chard or beet greens
- 1–2 medium beets if available
- 60–90 g carbohydrate from rice, potatoes, oats, or bread
- 25–35 g protein if this is a full meal
- 500–750 ml fluid
60–90 minutes pre-training
- Optional top-off snack: banana, jam sandwich, or rice cakes if the session is long
During the session
- Standard hydration and carb plan based on session length
This works best on endurance days, threshold intervals, or lift sessions where you care about maintaining bar speed and set quality across the workout.
A more precise supplement protocol
If you want the cleanest performance experiment, use a standardized beetroot product:
- Dose: 6–8 mmol nitrate
- Timing: 2.5 hours pre-session
- Trial duration: 3 separate sessions before judging
- Use case: key tempo run, interval day, long conditioning session, or dense lower-body lifting day
Run the same workout under the same fueling conditions and compare pace, power, rep count, bar speed, or total work. Nitrate is a tool for measurable output, not a ritual.
How to apply this
Use nitrate on the sessions where better efficiency matters most.
Weekly example for a hybrid athlete:
- Monday: Lower-body strength + accessories, no nitrate needed unless volume is high
- Tuesday: Interval run or assault bike session, take nitrate 2–3 hours pre-workout
- Wednesday: Easy aerobic or recovery work, skip it
- Thursday: High-volume full-body lift or sled/conditioning combo, use nitrate pre-session
- Friday: Rest or low-intensity movement
- Saturday: Long run, tempo ride, or mixed-modal benchmark, use nitrate pre-session
- Sunday: Recovery
Checklist:
- Choose one key session this week
- Use either a standardized 6–8 mmol dose or a large serving of nitrate-rich greens
- Take it 2–3 hours before training
- Avoid antibacterial mouthwash that day
- Keep carbs, fluids, and sodium appropriate for the workout
- Track one metric: pace, power, reps, or session RPE
- Repeat for 2–3 exposures before deciding if it is worth keeping
The bottom line for athletes
Swiss chard and beetroot greens are not just side dishes. Used strategically, they can be a real pre-training nitrate source that supports endurance economy, blood flow, and repeated-set output. The effect is most useful when you care about sustained performance, not one all-out lift. Dose it correctly, time it correctly, and pair it with the right session.
Sources worth knowing
The core mechanism and performance effect are well described in work by Bailey et al., Lansley et al., Jones, and later reviews by McMahon et al. If you want a simple rule, keep it this: high-nitrate greens or beetroot about 2 to 3 hours before demanding work, then measure the result honestly.