aerobic activity muscle-strengthening activities moderate-intensity aerobic activity physical fitness Aerobic activity moderate-intensity aerobic activity vigorous-intensity aerobic activity muscle-strengthening activities vigorous-intensity aerobic activity muscle-strengthening activities aerobic moderate-intensity aerobic activity vigorous-intensity aerobic activity muscle-strengthening activities muscle-strengthening activities bone-strengthening moderate-intensity aerobic activity www.cdc.gov/physicalactivity/basics/glossary/index.htm moderate-intensity aerobic activity muscle-strengthening activities muscle-strengthening activities www.cdc.gov/physicalactivity/basics/glossary/index.htm