The Numbers That Predict How Long You’ll Live

In 122,007 adults referred for treadmill testing, low versus elite fitness had adjusted all-cause mortality HR 5.04. This is a clinical referral cohort and association, not a promise that adding one MET multiplies lifespan. Measure with a lab test, a validated field protocol, or a wearable trend; compare only like with like. Example: a 45-year-old whose watch estimate rises from 28 to 33 mL/kg/min after months of training has a useful fitness trend even if the absolute estimate is biased. Move it with progressive aerobic work; see running and cycling.

PURE followed 139,691 adults in 17 countries: each 5 kg lower grip was associated with 16% higher all-cause mortality (HR 1.16). Measure 2–3 maximal trials per hand with the same dynamometer and protocol; record the best or average consistently. Example: 38 kg today is not “good” without age/sex norms; it is a repeatable baseline. Improve whole-body strength, not forearm squeezing alone, via resistance training.

In 34,485 community-dwelling adults aged 65+, each 0.1 m/s faster usual gait speed was associated with HR 0.88 for mortality. Mark a 4- or 10-meter course, use a rolling start, time the middle distance, and calculate meters ÷ seconds. Example: 4 m in 4 seconds = 1.0 m/s. Slowdown, new asymmetry, pain, dizziness, or falls merits clinical context—not a self-rehabilitation protocol.

Higher resting HR is associated with higher mortality in cohort meta-analyses, but illness, medication, heat, sleep, alcohol, dehydration and measurement all matter. HRV is even more device- and algorithm-dependent. Example: a stable 52 bpm baseline that becomes 68 for several mornings may signal recovery, infection, load or medication change; it is not an aging score.

Divide waist circumference by height in the same units. Example: 86 cm ÷ 178 cm = 0.48. The commonly used under-0.50 screen is useful because it scales waist to body size, but pregnancy, body composition and ethnicity complicate interpretation. Pair it with BP, glucose and function rather than treating it as a body-worth grade.

Use an appropriately sized validated upper-arm cuff, sit quietly, and average multiple readings on multiple days. Example: an isolated 142/88 after coffee is not equivalent to a home average of 142/88. Repeated elevation deserves a clinician-led plan; do not “biohack” pressure with supplements.

ApoB is a count proxy for particles that can enter arterial walls. It is often useful when LDL-C and triglycerides/insulin resistance disagree, but the correct target depends on absolute cardiovascular risk. Example: an ApoB of 82 mg/dL means little without age, BP, smoking, diabetes, LDL/non-HDL and clinical history. Use the lab decoder for context.

HbA1c estimates recent glycemic exposure; U.S. diagnostic categories use <5.7% normal, 5.7–6.4% prediabetes, and ≥6.5% diabetes when confirmed appropriately. Example: 5.8% should lead to context, repeat testing and risk discussion, not an internet diagnosis. Conditions affecting red cells can make A1c misleading.

hs-CRP is commonly categorized <1, 1–3, and >3 mg/L for cardiovascular risk context, but an infection, injury, dental issue, or hard workout can transiently elevate it. Example: a 5 mg/L result during a cold should not become a “chronic inflammation” identity; repeat under stable conditions if clinically appropriate.

Five-times sit-to-stand captures lower-body function; push-up capacity has a notable firefighter cohort association with cardiovascular events but is not general-population mortality proof. Example: record “five rises from a 45-cm chair, arms crossed, 9.4 seconds” rather than just “felt strong.” The protocol is the data.

Epigenetic clocks and pace-of-aging measures may predict outcomes at population level, but consumer offerings differ in assay, algorithm, repeatability and interpretation. Example: a $300 result that says “+4 years” gives no validated instruction more important than fitness, smoking, BP, waist and clinically indicated labs. Pay only if the uncertainty itself is worth it to you.

If you can track only five: choose a fitness proxy, grip or sit-to-stand, waist-to-height, home BP average, and risk-appropriate lipids/ApoB. That mixes function, exposure and clinical risk. A bad functional result can reflect unrecognized disease—do not assume it is merely motivation.