Abstract

In humans, regular physical activity has been associated with a wide range of positive mental health outcomes in various affect-related domains beyond well-established effects on specific aspects of cognition (Hillman, Erickson, & Kramer, 2008). These include reduced symptoms of depression and anxiety (Byrne & Byrne, 1993; De Moor, Boomsma, Stubbe, Willemsen, & de Geus, 2008; Herring, O'Connor, & Dishman, 2010; Herring, Puetz, O'Connor, & Dishman, 2012; Krogh, Nordentoft, Sterne, & Lawlor, 2011; Mead, Morley, Campbell, Greig, McMurdo, & Lawlor, 2009; Morgan, 1985; Ströhle, 2009), lowered odds of developing depressive disorders or feelings of distress (Physical Activity Guidelines Advisory Committee, 2008), and elevated mood (Janal, Colt, Clark, & Glusman, 1984; Wildmann, Kruger, Schmole, Niemann, & Matthaei, 1986). Mood effects range from feelings of general well-being (Knechtle, 2004; Sher, 1996) and accomplishment (Conroy, Smith, & Felthous, 1982) to ecstatic affective states, referred to as “runner's high” (Partin, 1983; Wagemaker & Goldstein, 1980). Deprivation from regular exercise can be associated with mood disturbances, notably increased state anxiety, tension, depression, and confusion (Mondin et al., 1996). Beyond mood, there are indications that exercise training influences pain perception (Koltyn, 2000) and studies in humans (Droste, Greenlee, Schreck, & Roskamm, 1991; Janal et al., 1984; Koltyn, 2000) and animals (Shyu, Andersson, & Thoren, 1982) have demonstrated elevated pain detection thresholds as a consequence of exercise, although muscle pain during intense exercise may not depend on opiodergic influences on nociception (Cook, O'Connor, & Ray, 2000).