Man boobs are caused primarily by one of two things:
1) Excess body fat
2) Gynecomastia
If it's Gynecomastia then you'll have to talk with a doctor. If it's purely excess body fat, then you need to work on reducing overall body fat. HalfHeartedGoal and Big Angry Hippo nailed it on the head.
Running is good, but the best solution to overall body fat reduction is a combination of these 5 tips:
1) Eat 5-6 small meals throughout the day. Each meal should be 2-3 hours apart. Each meal should contain one protein and one carb. The first meal should be eaten within an hour after waking.
2) Drink a cup of water at each meal.
3) Rest properly. This means taking at least 48 hours between strength training the same muscles, and it also means getting at least 7-8 hours of sleep per night. Lastly, it means taking 1-2 days off from exercising per week.
4) Cardio. This should be done at different intensity levels and different session lengths. Consider doing a low intensity/long session, a high intensity/short session and a few medium intensity/medium length sessions.
5) Strength Training. Strength train each muscle 1-3 times per week. You should lift a proper weight and perform the proper amount of sets/reps for your strength training method. If you need more guidance or exercise ideas you can head over
All of the above things combined will result in fat loss.
