Cross Training is for Everyone

The American Academy of Orthopaedic Surgeons suggests how to create a cross-training exercise program:
Opt for 30 minutes of aerobic exercise three times weekly as one component of your cross-training. Examples include walking, climbing stairs or skating.

Perform strength training exercises twice weekly, although not on consecutive days. An example is lifting weights.

Focus on flexibility as the third component. Examples that can be performed for five to 10 minutes daily include stretching or yoga.