Do both!

I played around with a fitness calculator today. The most significant variables were frequency, duration, and intensity of exercise and waist size and weight/body mass.

The result was your fitness age, which is younger, equal, or greater than your chronological age.

After trying different combinations of factors that could be changed (obviously factors like height and education level can’t be changed):

Body factors → Intensity of exercise ↓	Weight and waist (actual; no change)	Weight and waist (reduced)
Low intensity	Fitness age same as chronological age	Fitness age several years younger than chronological age
Moderate intensity	Fitness age several years younger than chronological age	Fitness age 10 years younger than chronological age
High intensity	Fitness age 10 years younger than chronological age	Fitness age half of chronological age