Improvement after a supplement is not the same as a comparative result
Start with the comparison. A before-and-after change alone cannot isolate the contribution of an ingredient.
Beetroot Extract
Selected research topic
Exercise performance
Some measured outcomes improved in human comparison studies. Read these findings with their populations and conditions.
Findings from a combination study cannot be attributed to this ingredient alone.
Some findings concern patients or people with a deficiency.
- Publications for this topic
- 26
- Human comparison publications
- 10
- Publications needing review
- 11
Findings in the studies
1,000-m run
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
General population · Combination study · two 1,000-m runs with recoveryMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Study comparison: caffeine plus beetroot juice versus placebo and beetroot juice
- Additional measurement information
- Primary outcome
- Measurement time
- two 1,000-m runs with recovery
Endurance Shuttle Walk Time
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
What the comparison group used was not confirmed.
Patient group · Combination studyMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
exercise time
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Patient group · Combination study · acuteMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Study comparison: Beetroot juice vs placebo
- Additional measurement information
- Primary outcome
- Measurement time
- acute
maximal knee extensor speed (Vmax)
- A better result than the comparison group was reported.General population
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Unknown intervention
- How results were compared
- Results were compared between groups. · Study comparison: acute nitrate-rich beetroot juice versus placebo
- Additional measurement information
- Primary outcome
- Measurement time
- acute; during the approximately 3-hour experiment
Other measured outcomes (13)
mean power
- A better result than the comparison group was reported.General population · Single ingredient · 2 hours before exercise
Measurement and study conditions
- Study type
- Controlled trial
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: counterbalanced crossover BRJ vs placebo
- Additional measurement information
- Secondary outcome
- Measurement time
- 2 hours before exercise
Peak power output
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
What the comparison group used was not confirmed.
Combination studyMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Participant characteristics were not confirmed.
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups.
- Measurement time
- Not confirmed.
peak walking time
- A better result than the comparison group was reported.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Patient group · Combination studyMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Patient group
- Ingredients tested
- Ingredient combination
- How results were compared
- Results were compared between groups. · Study comparison: beetroot juice vs placebo
- Additional measurement information
- Primary outcome
- Measurement time
- 3 hours for plasma nitrite; during exercise testing
power (Pmax)
- A better result than the comparison group was reported.General population
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Unknown intervention
- How results were compared
- Results were compared between groups. · Study comparison: acute nitrate-rich beetroot juice versus placebo
- Additional measurement information
- Primary outcome
- Measurement time
- acute; during the approximately 3-hour experiment
rowing time
- A better result than the comparison group was reported.General population · Single ingredient
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: beetroot beverage versus placebo
- Additional measurement information
- Secondary outcome
- Measurement time
- after 6 days of daily supplementation
Total work done during the sprints of the IST
- A better result than the comparison group was reported.General population · Day seven of supplementation
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Unknown intervention
- How results were compared
- Results were compared between groups. · Study comparison: Nitrate-rich beetroot juice versus nitrate-depleted beetroot juice during intermittent sprint testin
- Additional measurement information
- Primary outcome
- Measurement time
- Day seven of supplementation
Vo(2)
- A better result than the comparison group was reported.General population · Single ingredient
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Results were compared between groups. · Study comparison: nitrate-rich beetroot juice versus placebo
- Additional measurement information
- Biomarker
- Measurement time
- 6 days; exercise tests on days 4–6
1500-m TT
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.General population · Single ingredient
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Changes within the same group were compared. · Study comparison: Beetroot juice versus nitrate-free beetroot placebo in crossover design
- Additional measurement information
- Primary outcome
- Measurement time
- Eight-day supplementation; acute day 1 and chronic day 8
Isokinetic knee flexion power
Other human research, including observational studies and reviews
- A change was reported before and after use. Its cause cannot be isolated.General population · Single ingredient
Measurement and study conditions
- Study type
- Controlled trial
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Changes within the same group were compared. · Study comparison: Nitrate-rich versus nitrate-depleted beetroot juice in a crossover comparison; knee flexion power di
- Additional measurement information
- Secondary outcome
- Measurement time
- Testing three hours after the final supplement
resistance exercise performance
Other human research, including observational studies and reviews
- A change was reported, but the comparison could not be confirmed.General population · Single ingredient · 2.5 hours after supplementation
Measurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · General population
- Ingredients tested
- Single ingredient
- How results were compared
- Study comparison: Beetroot juice with negligible, low, moderate, or high nitrate versus placebo
- Additional measurement information
- Primary outcome
- Measurement time
- 2.5 hours after supplementation
Time-to-exhaustion
Other human research, including observational studies and reviews
- A change was reported, but the comparison could not be confirmed.
Several ingredients were tested together, so this ingredient’s individual effect is unknown.
Combination studyMeasurement and study conditions
- Study type
- Randomized controlled trial: subjects were randomly assigned to groups for comparison.
- Study population
- Human participants · Participant characteristics were not confirmed.
- Ingredients tested
- Ingredient combination
- Measurement time
- Not confirmed.
muscle strength gains
Research with unclear study subject or type
- Results for this measurement were mixed; no consistent conclusion can be drawn.
Measurement and study conditions
- Study type
- Systematic review
- Study population
- Recorded population category: General population. Whether the research involved humans needs confirmation.
- Ingredients tested
- Unknown intervention
- How results were compared
- Results were compared between groups. · Study comparison: Nitrate supplementation versus placebo across studies; 6 of 12 studies observed an ergogenic effect
- Additional measurement information
- Primary outcome
- Measurement time
- Acute or chronic dosing; optimal timing described as 2–2.5 hours before exercise for specified proto
walk distance
Research with unclear study subject or type
- A change was reported, but the comparison could not be confirmed.
Measurement and study conditions
- Study type
- Meta-analysis
- Study population
- Recorded population category: Patient group. Whether the research involved humans needs confirmation.
- Ingredients tested
- Unknown intervention
- How results were compared
- Study comparison: Exercise-capacity results varied by context; abstract does not state a single comparator
- Additional measurement information
- Secondary outcome
- Measurement time
- Pulmonary-rehabilitation study and short-term studies
This result is held for interpretation. That does not mean research found no effect.
Outcome groups needing additional review (13)
- average repetition time · Distinct papers needing additional review: 1Direction unclear: 1
- countermovement jump performance · Distinct papers needing additional review: 1Evidence criteria check: 1
- GXT trials · Distinct papers needing additional review: 1Evidence criteria check: 1
- isometric strength recovery · Distinct papers needing additional review: 1Evidence criteria check: 1
- modified Yo-Yo IR1 test · Distinct papers needing additional review: 1Evidence criteria check: 1
- MPO · Distinct papers needing additional review: 1Evidence criteria check: 1
- PPO · Distinct papers needing additional review: 1Evidence criteria check: 1
- time to task failure · Distinct papers needing additional review: 1Evidence criteria check: 1
- time-trial · Distinct papers needing additional review: 1Evidence criteria check: 1
- TT performance · Distinct papers needing additional review: 1Evidence criteria check: 1
- TTE · Distinct papers needing additional review: 1Evidence criteria check: 1
- V̇o2peak · Distinct papers needing additional review: 1Evidence criteria check: 1
- work decrement · Distinct papers needing additional review: 1Evidence criteria check: 1
One paper can appear under multiple measured outcomes or review reasons, so these counts should not be added together.
Representative outcome and study details
Human studies reported between-group improvement in 1,000-m run.
combination-ingredient studies · Individual ingredient effects cannot be separated · Human studies · between-group comparison
1 publications linked to this result
- Route, form, dose, or population details are incomplete, so the findings cannot be confirmed as directly comparable.
- Combination, formula, or class studies do not isolate this ingredient or establish synergy.
Data coverage and detailed study classifications
Paper counts are separated by research topic below. One paper may contribute to multiple findings.
Analysis status: Public-ready
Ingredient analysis date:
How the grade was determined: B
The 66.2 evidence score includes 12 independent human studies and 10 clinical studies in the representative benefit area. The B tier reflects evidence directness, repetition, and consistency together.
The grade is based mainly on the research area with the most evidence. It does not mean the same result was found in other areas.
Papers linked to this ingredient overall: 80
Papers linked to this topic 26 · distinct papers 26 · papers with a confirmed human comparison 10 · papers needing additional review 11
A publication may appear in more than one count. These numbers should not be added. Ingredient-wide papers, topic-linked papers, and sources in outcome groups use different scopes. Adding source counts may count the same paper more than once.
- 1,000-m run: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- 1500-m TT: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- average repetition time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- countermovement jump performance: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Endurance Shuttle Walk Time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- exercise time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- GXT trials: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Isokinetic knee flexion power: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- isometric strength recovery: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- maximal knee extensor speed (Vmax): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- mean power: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- modified Yo-Yo IR1 test: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- MPO: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- muscle strength gains: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Peak power output: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- peak walking time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- power (Pmax): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- PPO: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- resistance exercise performance: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- rowing time: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- time to task failure: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Time-to-exhaustion: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- time-trial: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Total work done during the sprints of the IST: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- TT performance: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- TTE: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- Vo(2): Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 1
- V̇o2peak: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- walk distance: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
- work decrement: Sources represented in this measurement group: 1 · Distinct papers with human comparisons for this outcome: 0
What the research found
1500-m TT
A change was reported before and after use. Its cause cannot be isolated.
Controlled study in people · Single ingredient · General population
Within-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
1,000-m run
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Endurance Shuttle Walk Time
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · Patient group
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
exercise time
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · Patient group
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Isokinetic knee flexion power
A change was reported before and after use. Its cause cannot be isolated.
Controlled study in people · Single ingredient · General population
Within-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
maximal knee extensor speed (Vmax)
The study reported improvement in this measurement.
Controlled study in people · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
mean power
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Peak power output
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · Unspecified population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
peak walking time
The study reported improvement in this measurement.
Controlled study in people · Ingredient combination · Patient group
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
power (Pmax)
The study reported improvement in this measurement.
Controlled study in people · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
rowing time
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Total work done during the sprints of the IST
The study reported improvement in this measurement.
Controlled study in people · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Vo(2)
The study reported improvement in this measurement.
Controlled study in people · Single ingredient · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
muscle strength gains
Results for this measurement were mixed; no consistent conclusion can be drawn.
Review · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
resistance exercise performance
A change was reported, but the comparison could not be confirmed.
Controlled study in people · Single ingredient · General population
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Time-to-exhaustion
A change was reported, but the comparison could not be confirmed.
Controlled study in people · Ingredient combination · Unspecified population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Analysis coverage and paper counts
1 paper · 1 measured outcome
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
walk distance
A change was reported, but the comparison could not be confirmed.
Meta-analysis · Unknown intervention · Patient group
Analysis coverage and paper counts
1 paper · 1 measured outcome
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
average repetition time
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
countermovement jump performance
The study needs further checking before its result can be interpreted.
Meta-analysis · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 2 measured outcomes
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
GXT trials
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
isometric strength recovery
The study needs further checking before its result can be interpreted.
Meta-analysis · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
modified Yo-Yo IR1 test
The study needs further checking before its result can be interpreted.
Controlled study in people · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
MPO
The study needs further checking before its result can be interpreted.
Controlled study in people · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
PPO
The study needs further checking before its result can be interpreted.
Controlled study in people · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
time to task failure
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
time-trial
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
TT performance
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
TTE
The study needs further checking before its result can be interpreted.
Meta-analysis · Unknown intervention · General population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Review overlap with primary papers is unknown; counts stay separate.
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Separable contribution · Unspecified population
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Unspecified population
Between-group comparison
Analysis coverage and paper counts
2 papers · 2 measured outcomes
2 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
Unspecified measured outcome
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · Unspecified population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
V̇o2peak
The study needs further checking before its result can be interpreted.
Controlled study in people · Single ingredient · General population
The comparison could not be confirmed.
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
work decrement
The study needs further checking before its result can be interpreted.
Controlled study in people · Ingredient combination · General population
Several ingredients were used together. This does not establish the effect of this ingredient alone or synergy.
Between-group comparison
Analysis coverage and paper counts
1 paper · 1 measured outcome
1 papers held from direction counts
Direction counts are distinct papers within each row. Outcome contributions count endpoint results, so one paper may contribute more than once.
How to read research findings
How should I read research findings?
Research guidesNo clear difference and an uninterpretable result are different
A reported null comparison contains a result. An abstract without an interpretable comparison leaves a question unresolved.
Paper counts and study counts are different
Count original research separately from research that reanalyzes it. Publication volume is neither replication nor a quality rating.
Side effects and combination findings
Findings from this ingredient alone are shown separately from those involving another supplement or medication.
No combination cautions are available to show in the current data. This does not guarantee safety.
Review 1 combination findings and 0 findings that outperformed an ingredient alone.
Reported improvements with combinations
Combination findings are grouped by how the study compared them. This is not a recommendation to combine ingredients.
Combinations with reported improvement
The combination showed improvement, but each ingredient's contribution is unclear.
CaffeineIn a randomized crossover trial of 20 healthy males, the combination of caffeine and beetroot juice significantly improved 1,000-m running performance compared to placebo (p < 0.01).