Biological age is a research construct, not one property that can be read directly from the body. Models built from different inputs can give the same person different results, and there is no generally accepted clinical standard that makes one commercial test definitive. InBody, InGrip and Max Pulse do not measure biological age. They show specific aspects of body composition, strength or the peripheral pulse wave, which are more useful under their real names.
Chronological age is time since birth. “Biological age” attempts to summarise molecular, physiological or functional changes associated with ageing, but models choose different inputs and outcomes. Some clocks are trained mainly on chronological age, while others target mortality, disease or function.
Biological age is therefore not a fixed property that can be measured once with certainty. A blood-based model, an epigenetic clock and a functional test may answer different questions for the same person and need not agree. Any result requires the algorithm name, inputs, reference population and known uncertainty.
A Nature Medicine review notes that there is still no consensus on how ageing biomarkers should be validated before clinical translation. A consumer result should not determine a diagnosis or treatment, or promise a number of years of life.
No. The InBody 970/970S used by MojeInBody does not list metabolic or biological age among its standard outputs. It measures bioelectrical impedance and uses it with other inputs to estimate body composition. It reports an estimated basal metabolic rate, but it does not turn that estimate into an age.
Some other consumer scales call an age-group comparison of estimated BMR “metabolic age”. That is a feature of a particular algorithm, not a universal BIA metric and not biological age.
On InBody, it is more useful to track muscle and fat mass, water, estimated BMR and their trends directly. Our separate metabolic-age article explains why an appealing age label may hide more than it clarifies.
Epigenetic clocks estimate age or a risk profile from methylation patterns at selected DNA sites. Methylation can influence gene regulation, but a value at one site does not simply mean that a gene is switched on or off. The reported result is a mathematical prediction from a specific model.
Different generations of clocks were designed for different targets and use different inputs. Their results are not automatically interchangeable, and a score change does not by itself prove that whole-body ageing or a future health outcome has changed.
These tools are valuable in research and clinical trials. For personal decision-making, however, there is no single standard, sufficient cross-laboratory repeatability or validated care pathway based on one commercial age number.
Grip strength measured with a dynamometer is one of the most robustly documented single predictors of functional aging and overall mortality in large population studies. The PURE study, which followed nearly 140,000 adults across 17 countries, found that every 5 kg drop in grip strength was associated with roughly a 16% higher risk of death – and grip strength predicted mortality more strongly than systolic blood pressure.
This is an observational association between groups, not a personal lifespan forecast or evidence that increasing grip alone will lower risk by the same percentage. Grip captures one part of muscle function and is also associated with age, illness, activity, nutrition and body size.
The European consensus group EWGSOP2 uses a grip strength threshold below 27 kg for men and below 16 kg for women as a screening signal for probable sarcopenia. That's exactly what it is – a screening cue, not a diagnosis. A low value means it's worth taking a closer look at muscle mass and activity levels, and possibly discussing it with a doctor, not that anything is automatically fine or automatically wrong.
Phase angle is calculated directly from resistance and reactance measured by bioimpedance. It relates to the electrical properties of tissue and the relative distribution of intracellular and extracellular fluid, but it does not directly measure every cell membrane, cellular health or biological age.
It varies with age, sex, body build, hydration, device and protocol. Lower values are associated with poorer status or prognosis in several clinical populations, but those associations cannot be turned into a universal personal health score.
Muscle mass from InBody is an estimate of body composition, not a direct measurement of muscle function. Combined with weight, water and grip-strength trends it can add context, but none of these values converts into a validated biological age.
Max Pulse optically records the fingertip pulse wave with photoplethysmography and derives APG indices and a proprietary vascular classification from its shape. The peripheral waveform is influenced by age and vascular tone, but also by blood pressure, temperature, posture, movement, signal quality and the device algorithm.
Single-site APG is not the same as clinical carotid–femoral pulse wave velocity. Max Pulse does not directly measure aortic stiffness or the mechanical properties of the whole arterial wall, and its device score must not be converted into a diagnosis or personal cardiovascular risk.
It can serve as an orientation-level screen when repeated under similar conditions and read with blood pressure and established risk factors. It is neither a biological clock nor a third pillar directly comparable with an epigenetic test.
The clearest approach is not to translate every result into years. Read each value according to the question it actually answers: body composition estimates structure, InGrip measures one functional performance, blood pressure measures arterial pressure and Max Pulse records a short peripheral optical pulse waveform.
A trend is useful only under a comparable protocol and is not automatic proof that the rate of ageing changed. Repeated loss of strength or unintended loss of muscle mass may prompt broader assessment; a one-off phase-angle or APG shift may also reflect measurement conditions.
None of these measurements or commercial age tests determines a diagnosis, treatment or lifespan. For healthy ageing, it is more practical to follow function and established modifiable factors than to chase one unvalidated age number.
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FAQ
No. The InBody 970/970S used by MojeInBody does not report metabolic or biological age. Some other scales call their own age-group comparison of estimated BMR “metabolic age”; it is neither biological age nor a universal BIA output.
Accuracy depends on the specific model and its target. Different clocks can give the same person different results, and there is no generally accepted clinical standard for changing care based on one consumer test.
Specific modifiable areas such as strength, physical fitness or blood pressure can improve. A change in a commercial ageing clock does not by itself prove whole-body rejuvenation, and no test can reliably promise a number of years gained.
Grip strength measures a maximal voluntary squeeze under a defined protocol. Population studies link it with function and health outcomes, but it is not a measure of biological age or a personal lifespan prediction.
No. They are different values with different methods, uncertainty and meaning. Keep their real names, compare like with like and do not pretend that together they form a validated clock.
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One age number tells you little. A series of repeated measurements of grip strength, muscle mass, phase angle and vascular elasticity shows you how your body actually changes over time – and where it's worth paying closer attention. At a measurement in Prague you can go through all of these functional markers in one place and compare your results in the portal, measurement by measurement.