Sustainability of natural movement activity

Introduction In efforts to increase sustainability, various commercial gyms and fitness centers have been redesigned or constructed to lower energy consumption. Such improvements include increased natural light, low-flow toilets, and more efficient lighting (Bogar, 2008; Bloyd, 2010). In the United States, a growing number of fitness centers have also in recent years achieved certification under the program of Leadership in Energy and Environmental Design (LEED). To further reduce energy consumption, studies have proposed, for instance, harnessing the power of treadmills or other exercise machines used by patrons to generate power for the building itself (Haji et al. 2010). In the future, it may be possible for gyms to become "net-zero" facilities or actually become net positive generators of energy.While such efforts are to be commended, energy consumption is only one aspect of sustainability. The United States Department of Health and Human Services (USDHHS) refers to sustainability in terms of the "triple bottom line--human health, environmental health and economic health" (USDHHS, 2011). Commercial gyms, fitness centers, and other physical activity facilities should be analyzed with regard to all components of sustainability. In general, different models of physical activity have different impacts on human and environmental health.The sustainability of different exercise models becomes more important as public health organizations continue to encourage more physical activity within populations. For example, the World Health Organization (WHO) calls for certain levels of activity based on age, but also emphasizes how additional physical movement can further reduce health risks (WHO, 2010). Curiously, there is no mention of where this activity should occur, nor is there any specific discussion of outdoor or indoor exercise, even though engaging in physical movement is influenced by accessibility of facilities, opportunities to participate, weather, safety, and aesthetic attributes (Humpel et al. 2002). Both outdoor and indoor facilities promote physical activity, as the number of gyms and parks per capita is associated with greater exercise participation (McInnes & Shinogle, 2009). Subjects perceive different benefits and costs to outdoor and indoor exercise, which lead to individual preferences for exercise settings (Huber et al. 2009).This article seeks to reframe the sustainability of exercise by looking at physical activity from a natural perspective. By focusing on all aspects of sustainability, the possibilities for how and where to engage in bodily exercise can be widened beyond traditional ideas. Other models of physical activity besides traditional gym exercise may both reduce energy consumption and increase health outcomes.Natural Movement Activity The last few decades have seen strong growth in fitness center memberships in the United States (Stern, 2011). In particular, commercial gyms have become highly competitive and are popular places for recreational exercise. In 2010, there were approximately 50.2 million gym memberships in the United States (IHRSA, 2011). These facilities offer an indoor environment with various machines and other manufactured equipment for exercise.In contrast, a growing area in the health and fitness sector focuses on natural movement, which seeks to replicate physical movements that were necessary for survival in the ancestral world (Cordain et al. 1998; Eaton & Eaton, 2003; O'Keefe et al. 2011). Humans evolved as hunter-gatherers during the Paleolithic era between 2.6 million and 100,000 years ago. During this time, a variety of physical movements were performed on a regular basis, such as walking, running, jumping, climbing, and lifting natural objects (O'Keefe et al. 2011). Early humans did not "exercise," but rather engaged in daily activity to secure food and shelter. As such, humans are genetically programmed to expect physical activity, and healthy gene expression depends upon it (Booth et al. …