how much is too much exercise?

Question
My best friend's name is Cooper. He is a 4-5 year old neutered pit mix (we think) and weighs in at a slim 70-80 pounds. Cooper and I enjoy regular bike rides in the woods around my home. I'm no vet but I think he is ostensibly in perfect health (and I endeavor to keep it that way).

During much of the time on our bike rides Coop is not restricted to running next to me. He frequently sets the pace by running out in front of me (in riding behind him I am pelted with pebbles he kicks up as he runs - I imagine that he is getting the same thing when he runs behind me. I know that Ceasar Millan would disapprove but I can wear goggles - I haven't found any for Cooper). His favorite thing to do is to run at full speed through the woods, darting over/under/around obstacles and literally leaping through the underbrush. Undoubtedly this behavior was bred into him and I like to allow him his 'wild dog time'.

The rides range from 3-8 miles (more often on the lower side of that range). We go at night and around a lake so I'm not worried about overheating. We make frequent stops where I'll let him just sniff around or wade in the lake for 10-15 minutes before resuming the ride. He seems to live for the bike rides.

I'm not sure just how many questions I can ask of you... I'll ask in order of importance and you can choose what you're willing to answer if you wish...

Sometimes Coop is a little stiff the next day and walks with a slight limp. My wife contends that this is a sign that I'm overdoing it with him. I argue that sometimes I'm a little stiff the next day too but it's not an injury and it feels fine once I'm using it again. The limp certainly disappears as soon as the bike comes out. How can I tell when he's overdoing it?

The area we frequent is a watershed. Sometimes our rides take us away from the lake and Cooper will find a swampy area to plop down in and drink from. How concerned should I be about the water he is drinking? I'm hoping that he'll be able to sense Giardia or other dangers in the water. I've tried to get him to drink from a water bottle (even bringing a portable bowl) but he'd rather find his own water. Should I be more concerned about what he's drinking?

His maniacal flights through the underbrush result in occasional small puncture wounds on his underside. (last time it looked like road rash - he must've got hung up on a stone wall or log). Do you think I should try to prevent his 'wild time'?

A few times he's torn the pads on his paws. I've been considering Ruff Wear Trex boots for him but my last dog wouldn't wear them. Any thoughts on the booties?


Hmmm... that sure did get long quickly. Sorry about that and thanks sooooo much for your insight!  

Answer
He just sounds like a real dog.  As long as you don't see to be pushing him, likely he knows when to back off.  I am a little concerned about the stiffness and limp.  Can you relate those times to longer or faster rides or more wild time?  You might back off a little, perhaps a little shorter, slower ride.  

Dogs love a chance to run free, and it is fine as long as you are away from traffic or other people and dogs.  She is slowing down now, but I still take my 14 year old Lab out and let her run loose at the river and in warmer weather have a swim,.  Let him enjoy himself.  

Don't worry about what Caesar Milan may think.  While leadership is very important, the better dog trainers have moved on to more positive methods.  

I don't think drinking the foul water is a problem either.  You do have his shots up to date and have him on heartworm remedy and perhaps a flea remedy?  The better ones protect dogs from other things too.