Legs need 48–72 hours between sessions.

Arms need 48.

And your cardio needs to fit around both, not compete with them.

Legs

Your largest muscle groups. Highest mechanical stress. Slowest to recover, especially after 40 when estrogen slows repair. Two sessions per week, 48–72 hours apart. That’s the sweet spot.

Arms

Smaller muscles, faster recovery. But don’t rush load: tendons and connective tissue still need time. Two upper body sessions per week, 48 hours apart minimum.

Cardio

Running and hilly walking load bone. Swimming and cycling protect joints and support metabolic health. All four have a place. The key is where they sit in the week, not competing with recovery, supporting it.