The best way to prevent overtraining when combining running and strength training is to be diligent in taking rest days, targeting different muscle groups on different days, and being gradual and deliberate when increasing weight or reps. This can be a tightrope walk and tricky to get right. If you feel like you are on the edge of overtraining or you’re serious about reaching a big goal, consult a coach or trainer who can help you balance your training schedule.