Sportprofil
Training uses up more than calories. Building muscle needs amino acids as material, minerals for contraction and cofactors for producing energy in the mitochondria. The sport profile measures how much of that is there.
If you train and get nowhere, it is not necessarily that you trained too little. Sometimes a building block is missing — and that can be measured instead of guessed.
What is measured here
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KapillarblutWhat the muscle needs in order to work
From the nerve impulse to a new muscle fibre there are five steps. Each step has its own material needs. If something is missing there, the chain does not break — it runs more slowly.
A simplified picture of what happens in skeletal muscle. The substances named are cofactors and building blocks of these steps, not promises of an effect.
NAD, Q10 and tryptophan — the energy axis
NAD is the coenzyme every cell uses to feed electrons into the respiratory chain. Q10 carries them on from there. Together the two decide how much ATP comes out at the end — and both fall with age.
The recycling route via NAMPT covers most of the demand. Building it anew from tryptophan is the slowest route — and the same one that runs differently during inflammation.
Q10 sits between Complex I and Complex III of the respiratory chain. Without NAD no electrons arrive; without Q10 they are not passed on. That is why the two are looked at together rather than one by one.
One raw material, three directions — and training sets the switch
Over 90 per cent of tryptophan goes into the kynurenine pathway, not into forming serotonin. Where the kynurenine pathway leads depends partly on how well trained the muscle is.
A simplified picture. The proportions are written as text on the branches because they differ so widely — a drawing to scale would not be legible.
The switch at the end of glycolysis
Pyruvate is the end product of sugar breakdown. From here there are two directions: into the mitochondrion, or on to lactate. Which direction wins out says something about how well the cell uses oxygen — and that is exactly why both values are measured together.
These figures come from blood measurements and cannot be carried over to a urine result. They are orientation values from the literature, not reference ranges — what counts is always the range the laboratory states on the lab report. In the specialist literature a ratio above about 25 is taken as a pointer to a disturbance of the respiratory chain, while a normal ratio with raised lactate and pyruvate points to a disturbance before that.
Lactate and pyruvate are organic acids and are part of the organic acids profile, along with the intermediates of the citric acid cycle and around twenty further markers. Urine is the more suitable sample for these substances: they are easier to recover from it than from plasma.
Measuring in blood has a known weakness, and it sits before the laboratory: the ratio needs two sample types collected and processed separately. On top of that, lactate rises from the tourniquet and from clenching the fist during collection, pyruvate is unstable, and the sample keeps for only about two days even when chilled. Unusual blood values therefore often come from the way the sample was taken rather than from the metabolism.
The limit that goes with this: most of these markers are non-specific. They show where it is worth looking more closely — they do not make a diagnosis, and they are read together with the other values in the profile.
View organic acidsProgress happens during the rest
Training sets the stimulus; the building comes afterwards. If the next stimulus comes too soon, or the raw material is missing, the strain adds up instead of the gains.
Schematic diagram of the supercompensation model, not measured performance data.
Where the figures come from
- de Guia RM et al., Aerobic and resistance exercise training reverses age-dependent decline in NAD+ salvage capacity in human skeletal muscle, Physiological Reports 2019.
- Janssens GE et al., Healthy aging and muscle function are positively associated with NAD+ abundance in humans, Nature Aging 2022.
- Chubanava S, Treebak JT, Regular exercise effectively protects against the aging-associated decline in skeletal muscle NAD content, Free Radical Biology and Medicine 2023.
- Agudelo LZ et al., Skeletal Muscle PGC-1α1 Modulates Kynurenine Metabolism, Cell 2014, and Nature Communications 2019.
- Kynurenine connection: how exercise shifts muscle tryptophan metabolism, American Journal of Physiology – Cell Physiology 2020.
- Kreider RB et al., ISSN position stand: safety and efficacy of creatine supplementation, Journal of the ISSN 2017.
- Jäger R et al., ISSN Position Stand: Protein and Exercise, 2018; Morton RW et al., British Journal of Sports Medicine 2018.
- Damas F et al., A review of resistance training-induced changes in skeletal muscle protein synthesis, Sports Medicine 2015.
- Robert Koch Institute, Vitamin D status in Germany, DEGS1.
- Lactate and pyruvate as inborn errors of metabolism screening markers, Discover Applied Sciences 2025.
- Mayo Clinic Laboratories, test description Pyruvic Acid, Blood; Lactate Pyruvate Panel, Plasma.
- Lactate and Lactate:Pyruvate Ratio in the Diagnosis and Outcomes of Pediatric Acute Liver Failure, PMC 2017.
What is NAD and why is it measured here?
NAD is a coenzyme through which nutrients pass their electrons into the respiratory chain. Without NAD there is no ATP. In muscle it is among the substances that decline most clearly with age.
NAD itself is rarely measured directly in routine testing. What can be measured are the building blocks and cofactors of the pathway — vitamin B3, vitamin B6, tryptophan and kynurenine — and they allow the situation to be read.
How are Q10 and NAD connected?
Both sit in the same chain. NAD delivers the electrons to complex I, and Q10 carries them on from there to complex III. If either one is missing, energy production stalls at a different point of the same chain.
The body makes its own Q10, and production falls with age. Statins inhibit the same synthesis pathway that produces Q10 — worth knowing when a value is being interpreted.
Can I have lactate and pyruvate measured?
Yes. Both are part of the organic acids profile and are measured from a urine sample you collect at home — along with the intermediates of the citric acid cycle and around twenty further markers. Urine is the more suitable sample for these substances; they are easier to recover from it than from plasma.
Measuring in blood is the harder route: the ratio needs two separately collected sample types, lactate rises from the tourniquet alone during collection, and pyruvate is unstable and keeps for only about two days even when chilled. One more thing: in a step test, lactate is measured under exertion in order to set training zones — a different question from the resting metabolism dealt with here.
When should I measure?
Not the day after a hard session. Exertion shifts several values for one to three days, among them inflammatory markers and iron parameters.
Two to three days of easy training or rest before the sample give a picture of everyday life rather than an exceptional state.
Does this replace performance testing?
No, it answers a different question. Performance testing measures what the body can do under exertion. These analyses measure what material is available for it.
The two complement each other. A non-medical practitioner or a doctor can tell you what a single value means for you.
Everything on this page comes from study results and describes groups, not individual cases. What a value means for you is something to discuss with a doctor or a non-medical practitioner — or with our expert network near you.