A fenced yard is a must for Jack Russell Terriers. It allows him to run, play, chase balls, etc. safely. Do not let your JRT run loose - a dog in a fenced yard or run is much healthier than one running loose for any car to hit or irate neighbour to shoot.
Planned exercise can be accomplished by walking your dog a mile or two, jogging with your dog, running him on a quiet country road or biking with him - you ride, he runs beside you at a steady pace (on lead of course!). Exercise keeps your dog's muscles in tone and provides an enjoyable experience for him.
Most puppies have big bursts of energy at one time of the day or another. These energy burn off times (we call them ‘crazy time’) can be positive or negative experiences. They can provide you with an excellent opportunity to structure some really fun and educational use of a playtime. The results of this type of session are easy training, fun learning plus the added bonus of a tired out pup at the end of it all.
A tired pup is a quieter and less destructive one. If you will be leaving the pup, do have an energy burn off session with the puppy before leaving. Even 5 to 10 minutes will make a tremendous difference. Puppies should be exercised at least every 4 hours if possible. Ordinary walks are good for your pup but these are not energy burn off where the pup rips and tears around at full speed, being himself, a silly, clumsy, typical puppy.
Try to keep in mind during your interactive playtimes with the pup, that every action, word or command can become a valuable part of the pup’s schooling and education. For example, simply tossing a toy for the pup actually has the potential to teach your puppy to retrieve on command, recall or return to you on command, sit on return to you and give up the article without a struggle or fight. All of these situations are basic, meaning that the pup will use these commands over and over again all through its life. The earlier you start to focus the pup on these commands, the more easily you and puppy will slide through the puppy months.