how much exercise for 5 month old?

Hello all,
Rocky is a few days short of 5 months old, and i'm just curious how much to exercise per day? i've talked to Howard33 a little bit and he puts about 3-4 miles per day on Tiberius which is i think 1 year old. i recently discovered the route i've been walking Rocky is only half of a mile! he runs and plays in the yard with my wife's yorkie, which is super fast so he puts on a good game of chase for Rocky, i'm just wondering if he is getting enough exercise. and are there any exercise guidelines to go by for each age/life stages?
Rocky's Information:
19 Weeks Old
45 Pounds
About 18"-19" Tall
Eating -Chicken Soup for the Puppy Lovers Soul (Large Breed Puppy) close to 2 Cups x 3 times a day

From what I understand it is not good to 'exercise' our dogs until they are at least 9mos. So, my wilson gets walked everyday and he does a couple 'sprints', but nothing excessive, nothing strenuous. From what I understand the emphasis is on bone development nothing to 'stress' the bones at an early age.

I didn't do anything special in terms of exercise - nothing routine or regimented - lots of play with the other dogs or myself. You don't want to stress the growing bones with long walks, and avoid walks on asphalt if possible - dirt/sand or grass - softer surfaces.

I also didn't limit her from jumping, which many folks advised me to do to protect her growing joints - when she was able, she was jumping on and of of the bed and pretty much anything else she was able to get up onto. Her OFA results are Excellent hips & Normal Elbows - so apparently the jumping didn't affect her at all!!!

At 19 weeks old I'd let the puppy decide to some degree when he's had enough - does he settle nicely at night when you settle down to watch TV and/or go to bed? If so, I'd say he's getting enough exercise. Also, exercise his MIND as well as his body - obedience training will tire him out much faster than running in the yard! Fifteen minutes of agility training for Jayda and she's wiped out for the night - but 20 minutes of play and fetch int he yard and she'll be ready to go in 2 hours!

you NEVER what to hard excercise a dog till the growth plates in their legs are closed!taht is anywhere from a year to 18 months. you are doing more damage to a dog than you think! please stop! your dog will have problems by the time he is at least 4 to 5 and wont be able to walk or get up. arthritis will set early. no concrete. so a little fetch in the back yard, no hard surfaces. walking, no running on sidewalks, let them walk in the grass.

hips and elbows are hereditary wether good or bad. its the joints on the "knees'" and "ankles" that you need to worry about of pounding and excessive exercise. and concrete in kennels.

This thread is helpful to me...thank you. Parts of our yard are concrete for walkways but have a lot of space with grass and soil. I do not take Elmo out on very hot weather because our roads are asphalt, I take him very early at dawn at 4am when the weather is cooler. I take him for walks more for socialization rather than exercise at 5 months. When the sun is up I just let him play with the other dogs, which is really mayhem with all those running, jumping and chasing, etc...and then he'd go inside the house, and lie there for hours...then he'd go again.