A 2018 study of 122,000 people found cardiorespiratory fitness predicts all-cause mortality more strongly than smoking, diabetes, or hypertension.
Primary source: Mandsager et al., JAMA Network Open, 2018
A six-year follow-up of 700+ adults showed sleep fragmentation, not duration, was the strongest predictor of cognitive decline and Alzheimer's risk.
Primary source: Lim et al., Sleep, 2013
A meta-analysis of 16 studies found strength training alone — independent of aerobic exercise — significantly reduced all-cause mortality in adults over 50.
Primary source: Saeidifard et al., Br J Sports Med, 2019
A landmark 2023 paper organised the chaos of aging into 12 cellular processes. Only three have human evidence behind them — the rest are still being studied in mice and yeast.
Primary source: López-Otín et al., Cell, 2023
The most rigorous trial of 16:8 fasting found no metabolic advantage over normal eating — and lost more than twice the lean mass of standard weight loss.
Primary source: Lowe et al., JAMA Internal Medicine, 2020
Estimate your aerobic capacity from age and resting heart rate. The single biomarker most strongly tied to all-cause mortality.
Daily target by weight and activity, with literature ranges. The 0.8 g/kg guideline is obsolete past forty.
Estimate years lived versus years lived in good health. Five habits with the strongest evidence base.
Calories your body burns at rest, using the Mifflin-St Jeor equation — the most accurate predictor for healthy adults.
Mifflin et al., 1990
Three questions adapted from the Horne-Östberg MEQ. Tells you when to train, eat, and do focused work.
Adapted from Horne & Östberg, 1976
Probability of a cardiovascular event in the next decade. Simplified from the AHA PREVENT 2024 model.
Khan et al., AHA PREVENT, 2024
Indicative — not a clinical diagnosis. Estimates how your metabolism compares to your real age, derived from metabolic syndrome markers.
Indicative model · Based on NCEP ATP III criteria
Stand up and sit down as many times as possible in 30 seconds, no hands. Strong predictor of mortality and functional independence.
Jones & Rikli, Senior Fitness Test, 1999
Walking speed predicts survival as well as many lab biomarkers. Below 1 m/s is the threshold of clinical concern.
Studenski et al., JAMA, 2011
Five-question screener validated internationally. Score ≥ 4 indicates suspected sarcopenia and warrants medical assessment.
Malmstrom & Morley, JAMDA, 2013
Real sleep time divided by time in bed. Above 85% is good, below 75% suggests insomnia. The standard PSG metric.
Buysse et al., Sleep Medicine Reviews, 2008
Approximation of Levine's PhenoAge using 5 of 9 markers. Predicts mortality better than chronological age. Get values from a standard blood panel.
Adapted from Levine et al., 2018