Comparative guide · 6 min read

Beetroot vs Citrulline for pumps and performance — two routes to nitric oxide compared

Updated 2026-05-17 · Reviewed by SupplementScore editors · No sponsorships

Beetroot juice (dietary nitrate) and L-citrulline both raise nitric oxide bioavailability, but via different pathways. Nitrate (beetroot) is reduced by oral bacteria and tissue enzymes to nitrite and then NO, particularly under hypoxic conditions — useful in endurance contexts. Citrulline is converted to arginine in the kidneys and then to NO via NO synthase — useful for resistance training pumps and high-rep work where blood-flow-related fatigue is relevant. They occupy different niches in the pre-workout space and can be reasonably stacked. Both have RCT evidence; both are tier-appropriate sports supplements.

Quick verdict

GoalBetter choiceWhy
Endurance (5K, cycling time-trial, mid-distance)BeetrootMeta-analyses show ~3% improvement in time-to-exhaustion and 1–2% in time-trial performance.
Resistance training pump / volume workCitrulline malatePérez-Guisado 2010 trial: 8 g citrulline malate increased reps to failure by ~52% on chest press.
High-altitude / low-oxygen performanceBeetrootNitrate-to-nitrite-to-NO pathway is upregulated in hypoxic tissue; modest signal in altitude trials.
DOMS / recovery from high-volume trainingCitrulline (mild)Modest signal in trials; beetroot's recovery effect is smaller and less consistent.
Blood pressure / cardiovascular adjunctBeetrootMeta-analyses show ~4/2 mmHg reductions in healthy adults; citrulline's BP effect is smaller and inconsistent.
Tolerability / convenienceCitrulline (powder)Beetroot juice is bulky; concentrated shots (e.g., Beet It) are pricey; powder is more convenient.

How they actually work

Beetroot — nitrate → nitrite → NO via the entero-salivary pathway

Dietary nitrate (NO3-) is concentrated in beetroot, leafy greens, and certain root vegetables. About 25% is reduced to nitrite (NO2-) by oral bacteria, then to NO in the stomach and tissues. This pathway is particularly active in hypoxic conditions (working muscle, ischaemic tissue) — making nitrate a candidate ergogenic in endurance contexts where oxygen delivery is limiting. Plasma nitrite rises 2–3 hours after dosing; ergogenic effects are typically seen 2.5 hours post-dose. Effective doses are 6.4–13 mmol NO3- (typically 70–140 mL of concentrated beetroot juice like Beet It, providing 400–800 mg nitrate). Antibacterial mouthwash blocks the effect (it kills the oral bacteria that perform the first reduction step).

Citrulline — kidney arginine production → NOS-mediated NO

L-citrulline is a non-proteinogenic amino acid converted to arginine in the kidneys (more efficiently than supplemental arginine itself due to first-pass intestinal metabolism). Arginine is the substrate for endothelial nitric oxide synthase (eNOS), producing NO at the vascular endothelium. Citrulline is also a buffer in the urea cycle, potentially helping ammonia handling during high-rep work. Effective doses for performance are 6–8 g of citrulline malate (1:1 ratio of citrulline to malate, so 3–4 g of pure citrulline equivalent) or 3–6 g of L-citrulline, taken 30–60 minutes before training.

Endurance — beetroot's strongest case

Meta-analyses of nitrate/beetroot in endurance trials show consistent modest improvements: ~3% in time-to-exhaustion at submaximal intensities, 1–2% in time-trial performance, reductions in the oxygen cost of submaximal exercise. The effect is most pronounced in recreational/sub-elite athletes; elite athletes show smaller effects, likely due to ceiling on improvement. Multi-day dosing (3–6 days at 6–13 mmol/day) appears to outperform single doses for some endpoints.

Resistance training — citrulline's strongest case

Citrulline malate at 6–8 g pre-workout has multiple RCTs showing increased reps to failure on multi-set protocols (bench press, leg press) and reduced post-workout soreness. Effect on 1RM is smaller; the strongest signals are on submaximal high-rep work where ammonia handling and blood flow may be limiting. Bodybuilding-style training (high volume, drop sets, multiple sets to failure) is where the supplement makes the most sense.

Blood pressure and cardiovascular

Beetroot has clearer BP signal: ~4/2 mmHg reductions in healthy adults, larger in hypertensive populations (~5–8/2–4 mmHg). This is a "side benefit" for athletes but a primary benefit for older adults using nitrate-rich vegetables in the diet for cardiovascular health. Citrulline has a smaller, less consistent BP effect.

Stacking

Beetroot + citrulline + caffeine + creatine is a reasonable evidence-based pre-workout stack. The mechanisms don't overlap completely (nitrate pathway vs eNOS pathway vs CNS stimulation vs phosphocreatine). Most "pre-workout" formulas include citrulline (often as citrulline malate) plus caffeine plus beta-alanine; beetroot is less commonly in formulas because of bulk and taste.

Practical rule. For endurance work (running, cycling, rowing): beetroot. For resistance training pumps and high-rep work: citrulline. For mixed (CrossFit, HIIT, hybrid programs): citrulline daily, beetroot before harder cardio sessions, or stack both pre-workout.

Dose, form, and timing

Beetroot: 70–140 mL concentrated shot (e.g., Beet It) providing 400–800 mg nitrate, OR 6–10 g beetroot crystals/powder providing similar nitrate. Take 2–3 hours pre-event for acute use. For multi-day loading, 1 dose/day for 3–6 days before competition. Avoid antibacterial mouthwash on dosing days. Expect dark urine and stool (harmless).

Citrulline: 6–8 g citrulline malate (1:1 ratio), OR 3–6 g L-citrulline, 30–60 minutes pre-workout. Powder form (taste is sour, tolerable) or capsules (need many to hit dose). Daily use is fine.

Safety

Beetroot: GI upset at higher doses; dark urine (beeturia, harmless); avoid in patients on PDE5 inhibitors (sildenafil) due to additive hypotension. Theoretical caution in patients with severe gastritis (nitrate-to-nitrite reduction in stomach).

Citrulline: well-tolerated. Rare GI upset at higher doses. Theoretical caution in patients on PDE5 inhibitors. Citrulline malate adds a small malic-acid load (relevant only at very high chronic doses).

Cost

Beetroot: concentrated shots are $2–4 per dose; powder is cheaper but bulkier. Multi-day loading runs $10–20 per event preparation. Citrulline: $0.30–0.80 per workout dose. Citrulline is generally cheaper per use.

Who should pick each

Pick beetroot if: you do endurance work (running, cycling, rowing, swimming), you have a specific event/race to peak for, you have stage 1 hypertension and want a cardiovascular benefit alongside athletic effect, you can plan 2–3 hours ahead for timing.

Pick citrulline if: you do resistance training with hypertrophy/high-rep focus, you do mixed-modality work (CrossFit, HIIT), you want a daily-use pre-workout staple, you want convenient powder form.

Use both if: you're a recreational endurance athlete who also lifts, you have multiple training goals, and you want to cover both mechanisms.

What we'd actually buy

For a recreational 10K runner with a target race: Beet It concentrated shot 70 mL daily for 6 days pre-race, plus 6 g citrulline malate on hard training days. For a hypertrophy-focused lifter: citrulline malate 6 g 30 minutes pre-workout, daily. For mixed CrossFit/hybrid athletes: 6 g citrulline malate daily; 140 mL beetroot 2 hours before benchmark workouts or competitions.

Sources

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