Track Your Physical Reserves in Just 5 Minutes

From peak power to lasting endurance—getting the full picture of vitality

A single squeeze on a traditional devices can tell you peak grip strength, A single maximum squeeze on a dynamometer might measure strength—but it misses a key element: fatigability. EFORTO’s approach—combining Grip Work (strength × endurance, normalized for body weight) and a self-perceived fatigue score—creates the Capacity-to-Perceived Vitality (CPV) ratio, offering a full-spectrum vitality assessment. (De Dobbeleer, L., Swart, M.M., Geerds, M.A.J., Baggen, R.J., Jansen, A.J.S., Tielemans, R., Silva, H., Lieten, S., Barbé, K., Peeters, G. and Vollenbroek-Hutten, M.M.R., 2023. Validity and reliability of Eforto®, a system to (self-) monitor grip strength and muscle fatigability in older persons. Aging Clinical and Experimental Research, 35(4), pp.835–845).

While dynamometers only capture one-time grip strength, EFORTO also captures how long strength is sustained—telling us about muscular endurance and fatigue, not just maximal output. (De Dobbeleer, L., Swart, M.M., Geerds, M.A.J., Baggen, R.J., Jansen, A.J.S., Tielemans, R., Silva, H., Lieten, S., Barbé, K., Peeters, G. and Vollenbroek-Hutten, M.M.R., 2023. Validity and reliability of Eforto®, a system to (self-) monitor grip strength and muscle fatigability in older persons. Aging clinical and experimental research, 35(4), pp.835-845.)

Isometric repetitive handgrip strength testing effectively detects increased muscle fatigability in frail older adults, highlighting its potential as a sensitive tool for early identification of functional decline. Kapan, A., Ristic, M., Leser, A., Felsinger, R. and Waldhoer, T., 2025. Assessment of muscle fatigability using isometric repetitive handgrip strength in frail older adults. A cross-sectional study. Journal of Translational Medicine, 23(1), p.215.

Among octogenarians who didn’t report fatigue, those with lower Grip Work and CPV scores and higher self-perceived fatigue were more likely to be pre-frail, even though traditional strength tests appeared normal.

(De Dobbeleer, L., Swart, M.M., Geerds, M.A.J., Baggen, R.J., Jansen, A.J.S., Tielemans, R., Silva, H., Lieten, S., Barbé, K., Peeters, G. and Vollenbroek-Hutten, M.M.R., 2023. Validity and reliability of Eforto®, a system to (self-) monitor grip strength and muscle fatigability in older persons. Aging clinical and experimental research, 35(4), pp.835-845.)

Lower Grip Work is tied to higher self-perceived fatigue, showing that diminished endurance often aligns with daily energy limitations reported by older adults.

(Knoop, V., Costenoble, A., Debain, A., Azzopardi, R.V., Vermeiren, S., van Laere, S., Jansen, B., Scafoglieri, A., Bautmans, I., Verté, D. and Beyer, I., 2021. The interrelationship between grip work, self-perceived fatigue and pre-frailty in community-dwelling octogenarians. Experimental Gerontology, 152, p.111440.)

Each unit increase in the CPV ratio corresponded to significant lower odds of being pre-frail (De Dobbeleer, L., Swart, M.M., Geerds, M.A.J., Baggen, R.J., Jansen, A.J.S., Tielemans, R., Silva, H., Lieten, S., Barbé, K., Peeters, G. and Vollenbroek-Hutten, M.M.R., 2023. Validity and reliability of Eforto®, a system to (self-) monitor grip strength and muscle fatigability in older persons. Aging clinical and experimental research, 35(4), pp.835-845.)

The connection between endurance and lived experience is clear: older adults with lower Grip Work tend to report higher self-perceived fatigue, meaning that a decline in hand endurance is often matched by a decline in daily energy levels (Knoop, V., Costenoble, A., Debain, A., Azzopardi, R.V., Vermeiren, S., van Laere, S., Jansen, B., Scafoglieri, A., Bautmans, I., Verté, D. and Beyer, I., 2021. The interrelationship between grip work, self-perceived fatigue and pre-frailty in community-dwelling octogenarians. Experimental Gerontology, 152, p.111440).