Strength train at least 2 days a week alongside your running
Added
CDC's adult guidelines say adults need at least 2 days a week of muscle-strengthening activity that works all major muscle groups, in addition to aerobic activity. Running counts as vigorous aerobic activity, so runners can hit the aerobic target and still be short on strength.
The result
Result: CDC: 150 minutes moderate or 75 minutes vigorous aerobic activity a week, plus muscle strengthening on 2 or more days.
Note: Not medical advice. Talk to your doctor before changing your training, diet, or supplements.
Source
CDC Physical Activity Basics (opens the original source in a new tab). Check it for the latest numbers before you act.