Cardiovascular fitness (VO2 max) in your 50s and 60s strongly predicts longevity. People in the top quartile of VO2 max for their age have around half the mortality rate of those in the bottom quartile. Building or maintaining it isn't optional — it's a major longevity intervention.
What to do specifically
Mix of Zone 2 (steady-state cardio, 150-200 min weekly) and Zone 4-5 (high-intensity intervals, 1-2 sessions weekly, 20-30 minutes each). The combination is more effective than either alone.
Examples of effective sessions
Zone 2: brisk walking, easy cycling, swimming, slow jogging. Zone 4-5: hill repeats, interval running, spin classes with intensity, rowing intervals. Stationary bike makes both easier on joints than running.
Test VO2 max if possible (gym or sports lab can measure). Track over years. Most women in their 50s can improve VO2 max by 15-25% over 12 months of consistent training — significant longevity improvement from a few hours weekly.