My favorite wooden salad servers are decorated with Bugsy’s teeth marks. Excluding unprovoked attacks on innocent squeaky toys and the occasional disemboweling of one of his stuffed animals, he wasn’t a destructive chewer by nature, and never damaged anything else. When I came home from work and saw him enjoying these Costa Rican souvenirs, I could hardly blame him, and felt no irritation whatsoever. I understood: it was hunting season.
Because we had a strong aversion to being mistaken for deer and accidentally shot, our exercise was severely limited during the 10 days that hunters roamed the area. Instead of two daily off-leash romps in the woods around our 150- acre farm, we took leash walks down the road. It was clearly not enough for Bugsy, who compensated by chewing on the wooden “sticks” that were conveniently lying around. Every time I use the salad set, I’m reminded that even with well-trained dogs, exercise matters if you want good behavior.
Training obviously helps with problem behaviors, but it’s not the only way to avoid trouble. Dog trainers have long valued the role of exercise in minimizing irksome canine activities such as barking, chewing, jumping around like lunatics, being unable to settle down or sleep well, digging, whining and relentless attention-seeking.
One casual experiment supports these views: a group of dogs was divided in half; one half worked on formal training while the other half had their exercise increased to two 30-to-45-minute sessions a day. After six weeks, the dogs who had additional training showed improvements in both their responsiveness to cues and their problem behaviors. The dogs who had extra exercise also exhibited problem behaviors less frequently, although their responsiveness to cues had not improved.
The relationship between exercise and behavior is complex and sometimes surprising. For example, Schneider et al. (2013) reported that more exercise was correlated with lower levels of fear, less aggression towards familiar dogs and reduced excitability. Jagoe and Serpell (1996) found that dogs acquired for the purpose of increasing their owners’ level of exercise have a lower incidence of certain types of aggression, including possessive aggression and socalled dominance aggression. Lindsay (2005) hypothesized that this is due to the general physiological effects of exercise. So, how does exercise affect behavior through physiological means?
Endogenous chemicals (those produced by the body) may play a role in the effects of exercise on physiology and behavior. Like people, dogs can achieve an emotional state described as the “runner’s high,” which may be why the chance to go for a run is greeted with enthusiasm by our canine companions. It may also be why so many people believe the old saying, “A tired dog is a good dog,” though the admirable behavior exhibited by dogs who are well-exercised may be due more to chemistry than to fatigue.
A runner’s high is caused by chemicals called endocannabinoids, which signal the reward centers of our brains. Endocannabinoids lessen both pain and anxiety as well as create feelings of well-being. Running triggers higher levels of these compounds, which is why running makes us feel good.
If you just snorted derisively and thought that running makes you feel terrible and you can’t imagine why people put themselves through such misery on purpose, you aren’t alone. Though most dogs are excited about running, the human species, outside of a small percentage of fanatics of the sport (or weirdoes, as we are sometimes called), isn’t interested. Yet, the potential to activate the chemicals that cause a runner’s high exists within all of us. The capacity to experience that rush of good feelings is shared by dogs and people, even if we aren’t all dipping into it as frequently as our long-ago ancestors, for whom running long distances was part of daily life.