40/25 kg is a test standard, not a training target
This is a reading, not a dial. Grip reflects whole-body strength trained elsewhere — Leong et al. 2015 has not shown that raising it directly changes anything.
A dynamometer reading, not a lift prescription. The 1.16 per 5 kg is a marker slope. Nobody in this set has shown that raising grip cuts death.
Dose
Male ≥40 kg / female ≥25 kg, one hand. Those knots are constructed (HR 0.8 at the cut, not 1.0). SHARE’s maximal-benefit threshold is 42 / 25. FNIH weakness is 26 / 16 — a different cut, not this target.
The 40/25 kg knots are constructed — HR 0.8 at the cut, not 1.0 — and the high side (−0.005/kg to a 0.7 floor) is constructed too; Leong’s slope is per 5 kg lower and has no high-side table.
Dose-response shape: monotone
How to get there
Grip is a readout of whole-body strength trained elsewhere. This set does not prescribe that training.
One-hand dynamometer, same hand, same posture, retested on a fixed interval; 40/25 kg is the standard you test against.
Past that standard there is no evidence more kilos buys anything — the high side of the engine curve is constructed.
Evidence, by endpoint
| Endpoint | Grade | Citation |
|---|---|---|
| All-cause mortality per 5 kg lower grip | B | Leong et al. 2015, The Lancet PURE, 17 countries, ages 35–70. 139,691 with known vital status; 3,379 deaths; median 4.0 y. Jamar; mean of each hand’s maximum. ACM HR per 5 kg reduction 1.16 (1.13–1.20). Stronger ACM predictor than systolic BP in that cohort (per-SD 1.37 vs 1.15). Abstract reports only this slope, not 40/25 knots. |
| All-cause mortality per 5 kg lower grip, pooled | B | Wu et al. 2017, Journal of the American Medical Directors Association 42 studies / 3,002,203 people. Per 5 kg decrease ACM HR 1.16 (1.12–1.20) — same centre as Leong, pooled. Lowest vs highest ACM HR 1.41 (1.30–1.52). Linear within 56 kg. Engine not moved onto this pool. |
| All-cause mortality by kg, dose-response | B | López-Bueno et al. 2022, Ageing Research Reviews 48 prospective cohorts of healthy adults, 3,135,473 people. ACM inverse 26–50 kg, close-to-linear, I² 45.7%. Does not report 16% per 5 kg. Tertile forest (12 studies, vs strongest third): weakest ACM HR 1.58 (1.40–1.78), middle 1.30 (1.17–1.44). |
| All-cause mortality per 5 kg, mean of both hands | B | Celis-Morales et al. 2018, The BMJ UK Biobank, 502,293 adults aged 40–69, 13,322 deaths, mean follow-up 7.1 y. Mean of right and left, not this UI’s one hand. Per 5 kg lower: women ACM HR 1.20 (1.17–1.23), men 1.16 (1.15–1.17). Splines: no deviation from linearity. FNIH weakness <26 kg men / <16 kg women is not this calculator’s 40/25. |
| All-cause mortality, tertile and kg threshold | B | López-Bueno et al. 2022, Age and Ageing SHARE, 121,383 adults (mean ~64) in 27 European countries and Israel, 896,836 person-years. Top vs bottom tertile ACM HR 0.41 (0.34–0.50) men / 0.38 (0.30–0.49) women. Maximal ACM threshold 42 kg men / 25 kg women — close to, not equal to, the engine’s 40/25. |
| All-cause mortality from a randomized strength intervention | X | Leong et al. 2015: further research is needed to test whether improvement in strength reduces mortality. No trial in this set assigned a grip-kg target and counted deaths. |
What the dose is
Forty kilograms in men and twenty-five in women, one hand, on a dynamometer. Those cuts are constructed: the engine sets HR 0.8 there, not 1.0. López-Bueno et al. 2022 (Age and Ageing, SHARE) put a maximal ACM threshold at 42 kg men / 25 kg women — close, not the same. Celis-Morales et al. 2018 used FNIH weakness cuts of 26 / 16 kg, which this calculator does not score.
What the evidence shows
Leong et al. 2015 (The Lancet, PURE) found ACM HR 1.16 (1.13–1.20) per 5 kg lower grip in 139,691 adults, and in that cohort grip out-predicted systolic blood pressure. Wu et al. 2017 pooled the same 1.16 (1.12–1.20) across 42 studies. López-Bueno et al. 2022 (Ageing Research Reviews) is the kg dose-response: inverse and close-to-linear from 26–50 kg, without a 16%-per-5 kg number. Celis-Morales et al. 2018 (UK Biobank, mean of both hands) is 1.20 in women and 1.16 in men per 5 kg lower, linear. All of that is grade B — prospective association with a dose-response, not a training trial.
What the number is not
It is not a demonstration that getting stronger lengthens life. Leong asked for that trial; this set does not contain it, which is why the intervention endpoint is grade X. It is not “16% more death” on the calculator track: 5 kg below 40/25 prints 0.96. It is not a both-hands mean, and it is not the FNIH sarcopenia cut.
How the kg are measured
PURE used a Jamar and, after a mid-study protocol change, the mean of each hand’s maximum. UK Biobank used the mean of right and left. The slider is one hand. Wang et al. 2022 (CHARLS) compared tertiles as odds ratios in Chinese adults 45+ — men OR 0.47 (0.35–0.64), women OR 0.51 (0.24–1.08), not significant — a different measure, a different statistic, and a reminder that the women’s signal is not settled in every cohort.
What argues against this
Grip here is a marker. Leong et al. 2015 itself ends by saying further research is needed to test whether improving strength reduces death — that is the claim this target would need, and it is not in the set. Celis-Morales et al. 2018 is the same observational slope on a different instrument (mean of both hands). The engine does not print Leong’s 1.16: 40/25 kg is HR 0.8, not 1.0, and 5 kg below the cut prints 0.96 because the 0.16 is added, not multiplied. López-Bueno et al. 2022 (Ageing Research Reviews) is a 26–50 kg spline, not a 16%-per-5 kg pooling, and its tertile forest (weakest 1.58, middle 1.30) is a steeper gradient than the engine’s additive segments. Wang et al. 2022 (CHARLS) reports tertile ORs, not HRs, and the women’s estimate is not significant (OR 0.51, 0.24–1.08).
Gotchas
- The calculator asks for one hand. Leong used the mean of each hand’s maximum; Celis-Morales used the mean of right and left. Those are not the same number as a single squeeze.
- 5 kg below the knot prints 0.96, not 1.16. Reading “16% more death per 5 kg” off the track overstates what the engine shows.
- FNIH sarcopenia cuts (<26 kg men / <16 kg women in Celis-Morales) are not this target. SHARE’s 42/25 is close to 40/25 by coincidence, not a lift.
- The high side (−0.005/kg to a 0.7 floor) is constructed. Leong’s slope is per 5 kg lower; it has no high-side table.
- López-Bueno 2022 is two papers. Ageing Research Reviews is the 26–50 kg ACM spline. Age and Ageing is the SHARE 42/25 threshold. Do not weld them.
Safety
- A max grip test is a measurement, not training. Screen before heavy loading in untrained, older, or cardiac-history people — this set does not prescribe a lift.
Educational content only — not medical advice, diagnosis, or treatment. Not a medical device; not FDA evaluated. Consult a qualified healthcare professional about your own health, and call emergency services for urgent symptoms. Full medical disclaimer →