Organic Acids (Urine) and Training: What Your Results Mean for Women Who Exercise

What Urine Organic Acids Actually Measure

Organic acids are small carbon-containing molecules excreted in urine after your cells burn carbohydrates, fats, amino acids, and neurotransmitters for energy. Think of them as the metabolic exhaust captured in a single urine sample. A comprehensive panel, such as the Genova Diagnostics Organix Comprehensive, groups these molecules into pathways: the citric acid (Krebs) cycle, fatty acid oxidation, B-vitamin-dependent reactions, neurotransmitter metabolism, detoxification markers, and oxidative stress indicators.

Because these analytes reflect real-time cellular chemistry, they respond to what you did in the last 48 to 72 hours, including how hard you trained, how long you slept, and where you are in your menstrual cycle.

How the Krebs Cycle Shows Up on Paper

The Krebs cycle intermediates, citrate, isocitrate, aconitate, succinate, fumarate, malate, and alpha-ketoglutarate, appear as a cascade on the report. In a well-nourished, sedentary state, these are low-to-moderate. During or after high-intensity exercise, citrate and succinate can spike because mitochondria are running faster than the cycle can clear intermediates. A 2020 review in Cell Metabolism demonstrated that citric acid cycle metabolites in blood and urine shift measurably within 30 minutes of aerobic exercise onset, which means a sample taken the morning after a hard interval session will look very different from a true resting baseline.

Fatty Acid Oxidation Markers

Suberic, adipic, and sebacic acids appear when your cells burn fat for fuel. Well-trained women who do fasted cardio or extended aerobic sessions often show elevated dicarboxylic acids. This is not pathology. It reflects efficient fat oxidation. The clinical error is flagging these elevations as a carnitine deficiency or a medium-chain acyl-CoA dehydrogenase (MCAD) problem without correlating to training history.

How Exercise Changes Specific Organic Acid Markers

Exercise is not one stimulus. A 20-minute zone-2 run, a 90-minute heavy lifting session, and a 3-hour trail run produce distinct metabolic signatures.

Lactate and Pyruvate

Lactate and pyruvate are the most exercise-sensitive markers on any organic acids panel. When you work above your lactate threshold, pyruvate production outpaces the mitochondria's ability to feed it into the Krebs cycle, and both metabolites spill into urine. Elevated urinary lactate-to-pyruvate ratio, normally below 25, can indicate mitochondrial dysfunction when seen in a sedentary person. In someone who trained hard the previous evening, a ratio of 30 to 40 may be entirely expected.

8-Hydroxy-2-deoxyguanosine (8-OHdG)

8-OHdG is a DNA oxidation marker included in some organic acids panels. Acute exhaustive exercise increases urinary 8-OHdG by 30 to 80 percent above resting values in studies of endurance athletes. A single 48-hour washout period before collection is the minimum; some sports-medicine practitioners recommend 72 hours after a competition or long training block before drawing a "true" oxidative stress baseline.

Methylmalonate and Methylcitrate

These B12-dependent markers are often used to screen for functional B12 insufficiency. Exercise itself does not dramatically change methylmalonate, but intense calorie restriction during training camps or relative energy deficiency in sport (RED-S) can deplete B12 status over weeks and raise methylmalonate. RED-S has a disproportionate impact on female athletes, particularly those in aesthetic or weight-class sports, making this marker worth watching in women who train hard and under-eat.

Alpha-Ketoglutarate and Succinate

Alpha-ketoglutarate (AKG) is both a Krebs intermediate and a substrate for collagen synthesis. Resistance training acutely lowers urinary AKG because working muscle consumes it rapidly. Chronic low AKG on a resting sample may reflect inadequate dietary glutamine or arginine, but again, sample timing is everything. Succinate elevation after strenuous endurance exercise is well-documented and resolves within 24 hours in most healthy women.

The Hormonal Layer: How Your Cycle and Life Stage Change the Results

Most organic acids reference ranges were built on populations that did not control for menstrual cycle phase, hormonal contraceptive use, or menopausal status. This is a genuine evidence gap, and your clinician should account for it when interpreting your report.

Reproductive Years and Menstrual Cycle Phase

Estrogen and progesterone influence substrate oxidation at the mitochondrial level. In the follicular phase (roughly days 1 to 14), estrogen predominates, and carbohydrate oxidation is slightly favored. In the luteal phase (days 15 to 28), rising progesterone shifts the balance toward fat oxidation and raises resting core temperature by about 0.3 degrees Celsius. Studies using indirect calorimetry show that women oxidize approximately 15 percent more fat per unit of exercise in the luteal phase compared with the follicular phase. This means dicarboxylic acid markers (fatty acid oxidation byproducts) will be naturally higher in the luteal phase even at the same exercise intensity.

Collecting your organic acids test in the same cycle phase each time if you are doing serial monitoring is a practical workaround until phase-stratified reference ranges exist.

PCOS

Women with polycystic ovary syndrome (PCOS) have documented mitochondrial dysfunction, elevated reactive oxygen species, and altered Krebs cycle flux independent of obesity status. A 2019 study in the Journal of Clinical Endocrinology and Metabolism found that women with PCOS had higher urinary markers of oxidative stress and altered amino acid metabolism compared with age- and BMI-matched controls. On an organic acids panel, this may appear as consistently elevated succinate, 8-OHdG, or markers of impaired branched-chain amino acid catabolism. Exercise training in PCOS generally improves these markers over 8 to 12 weeks, but a single pre-exercise intervention baseline may look alarming without context.

Perimenopause

During perimenopause (typically the late 30s to early 50s), estrogen fluctuates and then falls. Mitochondrial biogenesis is partly estrogen-dependent. Declining estradiol in perimenopause is associated with reduced mitochondrial electron transport chain efficiency and increased reactive oxygen species production in skeletal muscle. On an organic acids panel, perimenopausal women who exercise may show persistently elevated succinate or 8-OHdG even after adequate rest, not because they trained too hard, but because mitochondrial clearance is slower. Resistance training and high-intensity interval training (HIIT) are the best-studied interventions for restoring mitochondrial quality in this life stage.

Postmenopause

After menopause, the absence of cycling hormones removes the monthly variability, which actually makes organic acid panels slightly more interpretable. However, the absolute level of mitochondrial function has typically declined. Postmenopausal women may show lower baseline citrate and alpha-ketoglutarate, reflecting reduced Krebs cycle throughput, and higher 8-OHdG at rest. Hormone therapy (HT) in postmenopausal women has been shown to partially preserve mitochondrial membrane potential and reduce oxidative stress markers in skeletal muscle.

Pregnancy and Lactation Considerations

This article covers an interpretive lab, not a drug. The following applies to decisions around ordering and interpreting this test during reproductive transitions.

Pregnancy. Organic acid panels are not validated for use in pregnant women. Normal pregnancy involves profound shifts in amino acid metabolism, fatty acid oxidation, and oxidative stress markers that overlap with the pathological ranges used in non-pregnant adults. For example, urinary succinate and 3-methylhistidine rise in healthy pregnancy as muscle protein turnover increases. Ordering a comprehensive organic acids panel during pregnancy to guide supplement protocols is not supported by current evidence, and several supplements commonly recommended based on organic acids results, including high-dose alpha-lipoic acid and certain mitochondrial support compounds, have limited safety data in pregnancy. If you are pregnant, discuss any metabolic functional testing with your OB-GYN or maternal-fetal medicine specialist before proceeding.

Lactation. Breast milk composition is influenced by maternal metabolic status, but there is no established protocol for using maternal urine organic acids to guide lactation supplementation. Women in the early postpartum period have elevated oxidative stress markers as a physiological consequence of birth and recovery. If you are breastfeeding and concerned about nutritional adequacy, a standard micronutrient panel (B12, folate, ferritin, 25-OH vitamin D, zinc) provides clearer, validated clinical guidance than an organic acids panel.

Trying to conceive. Some functional medicine protocols use organic acids to identify mitochondrial or B-vitamin insufficiencies that may affect egg quality. The direct evidence linking organic acids results to fertility outcomes in humans is thin. This is an area of active interest but not yet clinical guideline territory. ASRM does not currently endorse routine organic acids testing as part of infertility evaluation.

Optimal Ranges vs. Reference Ranges: What the Difference Means for You

Reference ranges on a Genova report are typically the 5th to 95th percentile of a population. "Optimal" is a different concept: the level associated with best clinical outcomes, not merely the level common in the population.

For most organic acids markers, true outcome-linked optimal ranges in exercising women do not exist in the published literature. This is an honest evidence gap. What functional medicine practitioners mean by "optimal" in practice is usually:

• Lactate-to-pyruvate ratio: below 20 at rest (resting, well-nourished state)
• Citric acid cycle intermediates: within the lower half of the reference range on a non-exercise day
• 8-OHdG: below the lab median, ideally in the lowest tertile for age, collected 48 to 72 hours after last intense training
• Methylmalonate: below 2.0 mmol/mol creatinine (the Genova threshold for B12 functional insufficiency)
• Dicarboxylic acids (suberic, sebacic, adipic): mild elevation is acceptable in aerobically trained women; moderate-to-high elevation warrants carnitine status review

A 2022 systematic review on urinary organic acids in clinical nutrition noted that establishing sex-stratified and fitness-stratified normative data is one of the field's most pressing methodological needs.

How to Time Your Collection for the Most Useful Result

Getting the collection right matters more than almost any interpretive nuance. Follow these steps to reduce noise:

1. Rest period. Collect the sample at least 48 hours after any training session of moderate or greater intensity. Seventy-two hours is better if you completed a race, a competition, or a particularly demanding week.
2. First-morning urine. Collect the first void of the morning after an overnight fast. Urine concentration is more consistent, and diurnal variation in amino acid metabolites is minimized.
3. Cycle phase documentation. Note the day of your cycle on the requisition form. Day 3 to 5 of the follicular phase gives the most stable hormone backdrop for serial comparisons.
4. Dietary consistency. Eat your normal diet for at least 3 days before collection. An unusually high-protein day raises markers of amino acid catabolism. An unusually low-carbohydrate day raises dicarboxylic acids.
5. Hydration. Be normally hydrated. The lab adjusts most values to creatinine, but extreme dilution (urine specific gravity below 1.003) can still skew results.

Who This Approach Is Right For (and Who It Is Not)

Women Who May Benefit

• Endurance athletes with unexplained fatigue despite adequate training load and sleep, where you and your clinician want to rule out mitochondrial bottlenecks or B-vitamin insufficiency
• Women with PCOS who are beginning an exercise protocol and want a metabolic functional baseline
• Perimenopausal women with new-onset exercise intolerance or prolonged recovery who have normal standard bloodwork
• Women with a documented history of deficiency in B12, B6, or magnesium who want to track functional, not just serum, repletion

Women for Whom Standard Labs Are More Appropriate First

• Women whose primary concern is weight, cardiovascular risk, or blood sugar: a fasting lipid panel, hemoglobin A1c, fasting insulin, and CBC give clearer, guideline-validated answers faster
• Pregnant women (see section above)
• Women without access to a clinician trained in interpreting functional organic acid panels, because the risk of over-supplementation based on misread results is real

Interpreting Common Patterns in Active Women

The table below summarizes the most frequently flagged patterns in women who exercise regularly, what they often represent in the context of training, and what follow-up is reasonable.

| Finding | Common training-related cause | Follow-up before supplementing | |---|---|---| | Elevated lactate, pyruvate | Recent high-intensity exercise | Repeat after 72-hour rest | | Elevated suberic, adipic acid | Fasted cardio or fat-adaptation phase | Correlate with fasting carnitine | | Low alpha-ketoglutarate | Post-resistance training consumption | Repeat in follicular phase, rested | | Elevated 8-OHdG | Post-exercise oxidative stress | Repeat 72 hours post-training | | Elevated methylmalonate | Functional B12 insufficiency (or vegan diet) | Serum B12, methylmalonate, homocysteine | | Elevated succinate | Mitochondrial stress or post-exercise | Repeat; assess CoQ10 if persistent |

The Evidence Gap You Deserve to Know About

Women have been systematically underrepresented in the foundational studies that established organic acid reference ranges. Most normative databases were built using convenience samples in which the proportion of women, their menstrual cycle phase at collection, hormonal contraceptive use, and training status were either not recorded or not reported. This means every "normal" and "optimal" figure you see on a Genova report is extrapolated, to a meaningful degree, from data that may not represent you.

A 2021 NIH report on sex differences in metabolomics noted that urinary metabolite profiles differ significantly between sexes and are further modified by reproductive hormones, yet most metabolomics reference intervals remain sex-aggregated. This is not a reason to dismiss the test. It is a reason to interpret it in the full context of your training, your cycle, your life stage, and your clinical picture, rather than treating any single flagged value as a diagnosis.

Practical Next Steps After Your Results

If you have your Genova organic acids report in hand, here is a reasonable clinical workflow.

First, ask when the sample was collected relative to training and cycle day. If that information was not recorded, treat any pattern involving lactate, pyruvate, dicarboxylic acids, or 8-OHdG with extra skepticism and consider repeating with proper timing.

Second, cross-reference flagged functional deficiencies with standard serum markers. Methylmalonate elevation should prompt a serum B12 and homocysteine. Elevated xanthurenate (a B6 marker) should prompt a dietary B6 assessment. Functional markers gain credibility when they align with standard markers.

Third, before starting any supplement protocol, confirm that the dosing and duration are evidence-based. A 2020 Cochrane review on CoQ10 supplementation and exercise performance found no consistent benefit in healthy athletes, which illustrates that a functional marker elevation does not automatically translate into a benefit from supplementation.

Your organic acids result is a hypothesis generator, not a prescription pad. Use it as a starting point for a deeper conversation with a clinician who understands both functional medicine and exercise physiology, and who can place your numbers inside the full context of your hormones, training load, and life stage.