In one sentence
Pulse wave velocity is how fast the pressure wave of each heartbeat travels along your arteries, in meters per second, faster in stiffer arteries; vascular age restates it as the age at which that speed is typical, from a device that reports one or from VT's own estimate.
Why it matters
It measures directly what the pressure indices infer: the stiffness of the large arteries, which rises with age and faster with high pressure, and which decides how well each heartbeat is cushioned. In a meta-analysis of 17 longitudinal studies following 15,877 people for a mean of 7.7 years, those in the stiffest third had pooled relative rates of 2.26 for cardiovascular events, 2.02 for cardiovascular death and 1.90 for death from any cause against the most supple third; each 1 m/s of aortic pulse wave velocity corresponded to 14 to 15 percent higher rates after adjustment for age, sex and the usual factors, and the association was stronger in groups with existing coronary, kidney or blood-pressure conditions than in the general population (Vlachopoulos 2010). The reference VT reads a velocity against is the European collaboration that pooled 16,867 people from 13 centers in eight countries, 11,092 of them free of overt cardiovascular disease, diabetes and treatment, and 1,455 with optimal or normal blood pressure as the normal-value population; pulse wave velocity rose with each decade of age and with each blood-pressure category, the age rise steeper at higher pressures (Reference Values for Arterial Stiffness' Collaboration 2010).
What moves it
Age, most of all, and slowly. The blood pressure at the moment of measurement, because a more distended artery is a stiffer one, so a reading taken rested is not the same as one taken after coffee, a climb up the stairs or a stressful call. Heart rate, a little. Over months: body weight, aerobic exercise, blood pressure itself, and smoking, in the directions you would expect; the evidence for change with lifestyle is weaker than for the pressure and is read as your own trend.
How to measure it well
The clinical standard is carotid-femoral pulse wave velocity by tonometry, lying down and rested. At home, a scale that measures it from the feet: the Withings method combines a ballistocardiogram with an impedance pulse at one foot to time the wave from the heart to the leg and converts the time to a speed with your height. Calibrated on 106 people and tested on a separate 86 against the tonometry standard, the scale's bias was 0.25 m/s with a standard error of 1.39 m/s, graded acceptable on the arterial-stiffness society's classification, and its correlation with the carotid-femoral measure was 0.76; the authors asked for better repeatability (Campo 2017). So: the same scale, the same morning routine as for weight, standing still, before coffee and before training, and your correct height in the profile, because the speed is computed from it. A ring or watch that offers a cardiovascular age estimates stiffness from the shape of the optical pulse, a different method; VT keeps one vascular age a day, from the source you choose (Oura or Withings) or its own estimate, labeled with where it came from.
How Vitality Tracker uses it
The velocity is stored in m/s with the device it came from. Vascular age is stored in years with its source: a device's own figure, such as Withings or Oura, or, on a day with a blood pressure and no device figure, VT's own estimate from your blood pressure, age and height (and, for women, resting heart rate), by Kraushaar's vascular BioAge method (Kraushaar 2018). Vascular age is 40 percent of the arteries area of the Vitality Score, counting in full for 30 days and still used for 90; a change of source does not start a new line. Beside it VT shows the 10th-to-90th-percentile range for your age decade, from the reference population, and marks a value above it.
How far to trust the number
Trend-grade at home. The scale's standard error of 1.39 m/s against the standard is a large share of the difference between neighboring age decades in the reference population, so a single morning's vascular age can sit several years from the next morning's; read the monthly average and the direction over seasons, not a day. The tonometry standard is a measurement; the scale is a calibrated estimate of it; and VT's own vascular age, when no device reports one, is estimated from blood pressure, not measured in the arteries, with no claim beyond it. The age framing is the device makers' convention, kept because members know it; it is a comparison with a population, and it describes a measure.
Sources
- Vlachopoulos C, Aznaouridis K, Stefanadis C. Prediction of cardiovascular events and all-cause mortality with arterial stiffness: a systematic review and meta-analysis. J Am Coll Cardiol 2010;55:1318–27. doi:10.1016/j.jacc.2009.10.061
- Reference Values for Arterial Stiffness' Collaboration. Determinants of pulse wave velocity in healthy people and in the presence of cardiovascular risk factors: 'establishing normal and reference values'. Eur Heart J 2010;31:2338–50. doi:10.1093/eurheartj/ehq165
- Campo D, et al. Measurement of aortic pulse wave velocity with a connected bathroom scale. Am J Hypertens 2017;30:876–83. doi:10.1093/ajh/hpx059
- Vitality Tracker, How it works (shelf life); the engine catalogue of 15 October 2026 (the vascular age record and its source).
- Kraushaar LE, Dressel A, Massmann A. A novel principled method for the measurement of vascular robustness uncovers hidden risk for premature CVD death. J Appl Physiol 2018;125:1931–43. doi:10.1152/japplphysiol.00016.2018.