Bushman, Barbara A. Ph.D., FACSM
Q:I’VE SEEN SOME RECENT NEWS STORIES THAT SEEM TO SUPPORT THE BENEFITS OF DOG OWNERSHIP ON INCREASING PHYSICAL ACTIVITY OF HUMANS. I’M A DOG OWNER, AND I ENJOY PLAYING WITH MY DOG AS WELL AS DAILY WALKING MY DOG. IS THERE ANY RESEARCH TO SUPPORT MY PERSONAL EXPERIENCE THAT DOGS CAN BE HELPFUL IN ENCOURAGING PHYSICAL ACTIVITY AND PROMOTING OWNER HEALTH?
A:According to the U.S. Centers for Disease Control and Prevention, although approximately 49% of adults met Physical Activity Guidelines (15) for aerobic physical activity, more than half were not engaging in sufficient physical activity and the prevalence declined with increasing age (4) (Figure). In addition, obesity continues to be a concern; more than one third of adults in the United States are obese (2), and approximately 17% of kids (2 to 19 years of age) are obese (3). In turn, physical inactivity and being overweight are risk factors for type 2 diabetes, hypertension, dyslipidemia, and heart disease (1).
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With these realities in mind, finding ways to encourage more physical activity is of paramount importance. One of many areas that continues to receive attention as a possible way to promote physical activity is dog ownership, an area of potential promise considering the number of dog owners in the United States (Box 1). In 2013, the American Heart Association (AHA) released a scientific statement “Pet Ownership and Cardiovascular Risk,” which critically assessed the influence of pet ownership on the presence and reduction of risk factors for cardiovascular disease and cardiovascular disease risk (12). The AHA recommendations include the following: 1) pet ownership, particularly dog ownership, may be reasonable for reduction of cardiovascular disease (CVD) risk; and 2) pet adoption, rescue, or purchase should not be done for the primary purpose of reducing CVD risk (12).
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In this scientific statement, the AHA points out the critical need to find novel strategies and interventions to reduce the risk of CVD and the related morbidity and mortality (12). The AHA scientific statement reviews the impact of pet ownership on a number of health-related issues, including the following (12):
* Some studies have found an association between pet ownership and lower blood pressure
* Few studies are available related to pet ownership and lipid levels
* Dog walking (rather than just pet or dog ownership) seems to be associated with a lower incidence of obesity
* Most, but not all, studies have found a beneficial relationship between pet ownership and reaction to stress (e.g., lower heart rate and blood pressure responses)
* Studies with beneficial effects have included dogs or cats, but other pets also have been found to provide benefits, including goat, fish, chimpanzee, and snake ownership
* Pet ownership was not associated with reduced overall mortality in individuals without established CVD but may provide benefits for patients with established CVD
* Dogs seem to be the pet most likely to provide a positive influence on human physical activity
* Dog owners engage in more physical activity and walking and are more likely to meet recommended amounts of physical activity than are nonowners
* Physical activity levels do not seem to be associated with cat or other pet ownership
* Although data related to dogs are the strongest, this could be because dogs are more commonly owned and are most likely to increase the owner’s physical activity
In the previous list of findings, note the use of the words “associated” or “relationship.” Because most studies did not use a random assignment (most made comparisons between those who were already dog owners and nonowners), the impact of dog ownership on CVD risk reduction is not necessarily cause-and-effect, although an association has been shown. For example, healthier, more active individuals may be more likely to own and walk a dog. The AHA points out that although there could be other factors that are different between owners and nonowners that impact the outcomes, “there are plausible psychological, sociological, and physiological mechanisms for causation for many of the associations, particularly dog ownership and increased physical activity” (12).
Simply owning a dog will not automatically increase an individual’s activity, and not all dog owners walk their dogs (Box 2). When considering reasons that dog owners do not walk their dog, researchers in one study found the most common reason given was that the dog “self-exercised” or was an outside dog; other reasons given included that someone else was responsible for walking the dog, there was limited time or interest, the dog was too strong or did not behave, the dog was too old or unable to walk, or the dog owner was too old or unable to walk (13). When considering reasons owners walk their dog, researchers found a dog provided a source of motivation to be active and provided companionship (i.e., someone to walk with) and that owners felt a responsibility to exercise their dog and felt guilty if they did not regularly walk their dog (5). Obligation and self-efficacy are two potentially modifiable factors that have been identified as potential targets to promote dog walking (9). One way to encourage walking is to emphasize the benefits of walking for the dog’s health (both physical and mental well-being) (9). Improving self-efficacy with dog-handling skills specific to dog walking is another potential way to encourage dog walking (9). These factors could help promote initiation of dog walking and then, once begun, maintenance may be encouraged because of increased enjoyment by the dog and owner (9).
Many of the factors that influence people to walk their dog are similar to the factors reported for walking in general, although dogs may provide a couple of unique benefits: 1) motivation and encouragement to start walking and 2) social support and companionship to maintain the exercise program (5). Havinga plan of regular aerobic activity (e.g., dog walking), along with other prevention measures, is needed (12). The AHA suggests, “The primary mechanism through which acquisition of a dog leads to an increase in physical activity is believed to be behavioral intention (via the dog’s positive effect on the owner’s cognitive beliefs about walking), as well as motivation and social support for walking” (12).
As an example, consider the PPET Study (People and Pets Exercising Together) in which overweight or obese people along with an obese pet completed a 12-month weight loss study; a control group of overweight or obese people without a pet also received dietary and physical activity counseling (11). Both groups of people lost weight during the course of the year and the overweight pets also lost weight, showing a benefit to dog health along with that of the human owner. Both groups (those without dogs and those with dogs) reported similar levels of support from family, friends, and coworkers, including both helpful (e.g., cheerleader, accountability) and unhelpful (e.g., saboteur, inconsistent) influences. This is in contrast to the companion dogs that served as a buddy with positive influences only (including consistent initiator, enjoyment, and parental pride). The authors suggest that companion dogs can serve an important role as a social support system for engagement in physical activity and participation in a weight loss program (11).
In another study, nonowners who acquired a dog increased recreational walking by 31 minutes (adjusted for baseline variables) more than nonowners who did not acquire a dog (6). Researchers noted that “intention to walk” was associated with both dog acquisition and increased recreational walking (6). However, the order of events is not known. Individuals may have acquired a dog and then, in caring for the dog, increased their intent to walk. Another option is that individuals may have increased their intention to walk and then acquired a dog to help put that intention into action (6). Researchers suggest the former to be the more likely option; acquiring a dog only to promote walking seems unlikely because previous studies indicate the main function of pet dogs to be companionship (6).
In addition to the many identified positive factors associated with dog ownership/walking, the impact of dogs on others should be considered. Dogs have the potential to negatively impact physical activity in urban environments because of dog litter in public places and stray or uncontrolled dogs (14). Thus, responsible dog owners, including those who regularly walk their dogs on a leash and under control and who pick up dog litter, are important to keep environments safe and inviting for everyone to be active (14). For additional considerations on keeping pet ownership healthy and safe, see resources in Box 3.
Numerous potential health benefits of pet ownership have been suggested by researchers, although cause-and-effect conclusions are somewhat limited because most studies are, because of practical reasons, cross sectional rather than randomized interventions. Dogs may promote physical activity through motivation and encouragement to initiate a program, as well as social support and companionship to continue an activity program. Dog walking has the potential to improve owner health through regular physical activity and also can promote pet health at the same time.
Ready to “go for a walk”?
Helpful resources on being active with your pet:
From: WebMD. Exercise for Dogs http://pets.webmd.com/dogs/guide/exercise-dogs
From: American Heart Association. “Staying Active with Your Pet” http://www.heart.org/HEARTORG/GettingHealthy/HealthierKids/HowtoMakeaHealthyHome/Staying-Active-with-Your-Pet_UCM_310807_Article.jsp
1. American College of Sports Medicine. ACSM’s Complete Guide to Fitness & Health
. Bushman BA (editor). Champaign (IL): Human Kinetics; 2011, 396 p.
4. Centers for Disease Control and Prevention/National Center for Health Statistics/Office of Analysis and Epidemiology. Health, United States, 2011; [cited 2013 Aug 5]. Available at http://www.cdc.gov/nchs/hus.htm
5. Cutt HE, Giles-Corti B, Wood LJ, Knuiman MW, Burke V. Barriers and motivators for owners walking their dog; results from qualitative research. Health Promot J Austr. 2008; 19: 118–24.
6. Cutt HE, Knuiman MW, Giles-Corti. Does getting a dog increase recreational walking? Int J Behav Nutr Phys Activity. 2008; 5: 17.
7. Christian HE, Westgarth C, Bauman A, Richards EA, Rhodes RE, Evenson KR, Jayer JA, Thorpe RJ Jr. Dog ownership and physical activity: a review of the evidence. J Phys Activity Health. 2014; 10: 750–9.
9. Hoerster KD, Mayer JA, Sallis JF, Pizzi N, Talley S, Pichon LD, Butler DA. Dog walking: its association with physical activity guideline adherence and its correlates. Prev Med. 2011; 52: 33–8.
11. Kushner RF, Blatner DJ, Jewell DE, Rudloff K. The PPET Study: people and pets exercising together. Obesity. 2006; 14: 1762–70.
12. Levine GN, Allen K, Braun LT, Christian HE, Friedmann E, Taubert KA, Thomas SA, Wells DL, Lange RA. Pet ownership and cardiovascular risk: a scientific statement from the American Heart Association. Circulation. 2014; 127: 2353–63.
13. Reeves MJ, Rafferty AP, Miller CE, Lyon-Callo SK. The impact of dog walking on leisure-time physical activity: results from a population-based survey of Michigan adults. J Phys Activity Health. 2011; 8: 436–44.
14. Toohey AM, Rock MJ. Unleashing their potential: a critical realist scoping review of the influence of dogs on physical activity for dog-owners and non-owners. Int J Behav Nutr Phys Activity. 2011; 8: 46.
15. U.S. Department of Health and Human Services Web site [Internet]. 2008 Physical Activity Guidelines for Americans. 2008. Atlanta (GA): USDHHS; [cited 2013 May 15]. Available at: http://www.health.gov/paguidelines
© 2014 American College of Sports Medicine.