Body · topic 4 of 4
Intrinsic capacity
Why grip, walking speed, chair stand and SPPB belong in the same room — and which parts of the picture Verve does not measure
Intrinsic capacity is the World Health Organization's name for everything a person's body and mind can do — their functional reserve, taken as a whole rather than as a list of diseases. It was defined in the 2015World Report on Ageing and Health as the centrepiece of a deliberate shift: away from asking what conditions an older adult has, and toward asking what they are able to do and whether that is changing.
The five domains
The framework scores a person across five areas: locomotion(strength and mobility), vitality (energy, nutrition and resilience to physical stress), cognition,sensory capacity (vision and hearing) andpsychological wellbeing. Many of the instruments are ones geriatric medicine already uses: grip strength, usual-pace walking speed, the five-times chair rise, and the Short Physical Performance Battery that scores balance, gait and chair stand together.
Lower intrinsic capacity predicts disability and mortality in older adults, and in 2022 the WHO added ageing-associated decline in intrinsic capacity to the eleventh revision of the International Classification of Diseases. What researchers most want from it, though, is not a single reading but a trajectory: a person followed over time, so that a decline is seen early enough to do something about it — often while they are still robust and have no diagnosis at all.
What Verve measures, and what it does not
| Domain | WHO's screening measures | In Verve |
|---|---|---|
| Locomotion | chair rise, gait speed, SPPB, grip | All four, with cited cut-offs |
| Vitality | weight loss, appetite, muscle mass | Lean mass, ALMI, FFMI, body fat, physical activity level |
| Cognition | orientation, recall | Not measured |
| Sensory | vision, hearing | Not measured |
| Psychological | mood, depression screen | Not measured |
Two of the five domains, and those are the two whose instruments are objective rather than questionnaires — the half of intrinsic capacity a phone and a tape measure can honestly do. The other three are screened in clinic with validated tools, and Verve does not attempt them: a reaction-time widget presented as a cognition score would be exactly the kind of invented measure this app exists to avoid.
The ceiling, and the measure that has none
The locomotion tests were designed to detect decline in people over about 65. In a healthy 40-year-old, SPPB reads 11 or 12 out of 12, chair stand is comfortably under the cut-off, and gait speed is well above it — and that will stay true for a long time. Verve keeps these tests because they are the right instruments for later, and because a baseline recorded while a number is boring is what makes a later change visible. But they are not where a younger user's signal lives.
The measure that varies across the whole lifespan and predicts mortality at every age iscardiorespiratory fitness. That is why METs are Verve's primary metric rather than a functional battery: it is the one capacity that is already informative at 30, and still informative at 80.
What Verve deliberately does not do
Verve does not compute an intrinsic capacity score. The composite's value as a proxy for healthy ageing is still being established — that is the explicit purpose of the current research programmes — and a single number synthesised from two of five domains would be an overclaim wearing the WHO's vocabulary. Each measure is shown on its own, against its own cited range, with its own history. The trajectory is the point; the arithmetic can wait for the evidence.
References
- World Health Organization. World Report on Ageing and Health. Geneva: WHO; 2015.
- Beard JR, Officer A, de Carvalho IA, et al. The World report on ageing and health: a policy framework for healthy ageing. Lancet. 2016;387(10033):2145-2154.
- World Health Organization. Integrated Care for Older People (ICOPE): Guidelines on community-level interventions to manage declines in intrinsic capacity. Geneva: WHO; 2017.
- Cesari M, Araujo de Carvalho I, Amuthavalli Thiyagarajan J, et al. Evidence for the domains supporting the construct of intrinsic capacity. J Gerontol A Biol Sci Med Sci. 2018;73(12):1653-1660.
- Beard JR, Si Y, Liu Z, Chenoweth L, Hanewald K. Intrinsic capacity: validation of a new WHO concept for healthy aging in a longitudinal Chinese study. J Gerontol A Biol Sci Med Sci. 2022;77(1):94-100.
- World Health Organization. ICD-11 for Mortality and Morbidity Statistics, MG2A: Ageing associated decline in intrinsic capacity. 2022.
- Guralnik JM, Simonsick EM, Ferrucci L, et al. A short physical performance battery assessing lower extremity function. J Gerontol. 1994;49(2):M85-94.
- Mandsager K, Harb S, Cremer P, et al. Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open. 2018;1(6):e183605.