It is generally agreed by breeders and vets that environmental factors, including nutrition and exercise, influence development.

Your puppy will usually be on several small feeds daily when you first bring him/her home.  Ask your breeder what the pup has been eating and ensure the diet you feed them has all the nutrients necessary for a growing puppy.  It may be a good idea to check the diet with your vet.  It is also important that you do not let your puppy (or your adult Bernese) become fat.  Obesity is not good for their health or fitness.

Exercise is important for adult and puppies alike.  However be careful not to over-exercise a youngster as this will put excess stress on muscles and joints and may cause irreparable damage.

As your puppy grows, slowing increase exercise and play times.  It is important to supervise puppies at play.  All growing puppies need lots of rest and every effort should be made to ensure this is received.