How do you define "punishment" for dog training? In the psychological sense, punishment is going to mean either denial of a positive thing (treats, toys, etc) or use of a negative thing (scolding, physical methods like spraying water or citronella, poking (dog whisperer's method) or straight up violence).
To me, this is not the way to train a dog. You can still be a leader by providing their food at set times, by giving them play time and ample walks, and by truly mastering yourself so you do not unnecessarily use physical or verbal abuse on them. To me, I've never had to punish my dogs, all I'll do is say "No" in a particular tone of voice. Other than that, I just reinforce the good behaviors, allow them wiggle-room for breed-specific behaviors, and make sure they have plenty of exercise and a good diet.