Sustained rhythmic activity that strengthens the heart, vessels, and muscles and improves the body's use of oxygen. Greater fitness is among the strongest predictors of a longer life. Core gains — lower risk of early death, heart disease, high blood pressure, and high blood sugar — are well supported; overuse injuries are common but minor and serious heart events rare. (Full Review)
| Marker | Target | Why |
|---|---|---|
| VO2 max | Above age/sex 75th percentile | Best single predictor of longevity and training progress |
| Resting heart rate | ~50–65 bpm | Falls as fitness improves; sudden rise flags overtraining or illness |
| Heart rate variability (HRV) | Higher and stable vs. personal baseline | Reflects recovery and autonomic balance; guides training load |
| Blood pressure | <120/80 mmHg | Aerobic training lowers it; tracks cardiovascular benefit |
| Resting HR recovery (1 min post-exercise) | Drop of >12–20 bpm | Faster recovery indicates better cardiovascular fitness and autonomic health |
| HbA1c | <5.4% | Confirms metabolic benefit of training |
| Fasting glucose | 75–90 mg/dL | Tracks insulin sensitivity gains |
| hs-CRP | <1.0 mg/L | Marker of systemic inflammation, which training lowers |
| ApoB | <80 mg/dL | Number of artery-clogging cholesterol particles; complements training's cardiovascular effect |
Cadence: Resting heart rate and blood pressure every few weeks early on; aerobic capacity every 8–12 weeks; metabolic and lipid markers every 6–12 months