What are the best exercises for cardiovascular stamina in men over 40?

The most evidence-supported training structure for cardiovascular stamina in men over 40 consists of: (1) zone 2 aerobic base building (brisk walking, easy cycling, rowing at conversational pace), 150–180 minutes per week in 3–5 sessions, which builds mitochondrial density, improves fat oxidation, and lowers resting heart rate; and (2) VO2max intervals (4×4 minutes at 90–95% max effort with 3-minute recoveries) 1–2 times per week, which acutely improves cardiac output ceiling (Wisløff et al., Circulation, 2007).

Zone 2 training is the foundation; interval training is the ceiling-raiser. Neither alone is ideal. The 80/20 distribution (80% of training time at easy/moderate intensity, 20% at high intensity) is used by elite endurance athletes and is supported by cardiovascular medicine research for men over 40 who want maximum longevity-relevant fitness gains without excessive injury risk. Exclusive HIIT without zone 2 base work builds some fitness but misses the mitochondrial density and fat oxidation adaptations that are the most longevity-relevant cardiovascular adaptations.

Honesty Scale: Solid (1) for zone 2 training and its cardiovascular adaptations. Solid (1) for HIIT/VO2max intervals increasing cardiac output.

What to do: Add up your easy aerobic training minutes per week. If it is below 150, build there first before adding any high-intensity work. Your zone 2 target heart rate is approximately 70% of your max heart rate (roughly 220 minus your age). If you can speak in complete sentences comfortably, you are in zone 2.

For the full picture, read The Stamina Deep Dive