Endpoint
Maximal oxygen uptake
CAT:outcome/vo2maxreported in mL/kg/min
Method
Maximal oxygen uptake (VO2max, VO2 peak) by breath-by-breath indirect calorimetry during an incremental exercise test to volitional exhaustion. Modality and ramp protocol recorded on the edge.
The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.
Notes
Added 2026-08-16 after a search-precision review found creatine trials reporting aerobic endpoints with nowhere to map them. Not interchangeable with time-to-exhaustion, and the distinction is the point: VO2max is a physiological ceiling, time to exhaustion is a performance duration, and a supplement can move one without the other. Recording an aerobic finding against time-to-exhaustion because no better node existed is exactly the near-miss the object-plausibility validator refuses.
Findings
3 findings from 3 compounds, strongest first.
nitrate — no detected effect on
LikelyGrade B, Likely. Human evidence, limited replication or design limits.FindingNull result“Nitrate supplementation decreased VO2 (MD - 0.04 L/min, P < 0.00001) but had no significant effect on VO2max or blood lactate levels.”
Quoted verbatim from The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis.. - Study
- meta-analysis
- Population
- adults engaging in endurance-based activity
The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis.2021PMID:34243756An author is affiliated with a producer
L-arginine — increases
LikelyGrade B, Likely. Human evidence, limited replication or design limits.Finding“This meta-analysis indicated that supplementation with L-arginine could increase VO2 max in healthy people.”
Quoted verbatim from The effect of L-arginine supplementation on maximal oxygen uptake: A systematic review and meta-analysis.. - Study
- meta-analysis
- Population
- healthy people; overall pooled estimate across 11 randomized clinical trials
The effect of L-arginine supplementation on maximal oxygen uptake: A systematic review and meta-analysis.2021PMID:33587327
magnesium(2+) — decreases
PreliminaryGrade D, Preliminary. Non-human or in vitro only.Finding“Compared with the placebo, the VO2max was lower ( p = 0.005) after magnesium supplementation in 11/15 participants (mean decrease: 3.1 ± 3.6 mL/kg/min).”
Quoted verbatim from Short-Term Magnesium Supplementation Has Modest Detrimental Effects on Cycle Ergometer Exercise Performance and Skeletal Muscle Mitochondria and Negligible Effects on the Gut Microbiota: A Randomized Crossover Clinical Trial.. - Study
- crossover
- Participants
- 15
- Duration
- 9 days
- Dose
- magnesium chloride 300 mg (ReMag) twice per day for 9 days
- Population
- Healthy regularly exercising adults aged 18-40 (8 male, 7 female); primary outcome; incremental cycle ergometer test to volitional fatigue with breath-by-breath indirect calorimetry
Short-Term Magnesium Supplementation Has Modest Detrimental Effects on Cycle Ergometer Exercise Performance and Skeletal Muscle Mitochondria and Negligible Effects on the Gut Microbiota: A Randomized Crossover Clinical Trial.2025PMID:40077784Industry funded