A growing body of literature demonstrates that exercise can enhance well-being and mood (Berger and Motl, 2000; Biddle, 2000; Otto and Smits, 2011) and may even be used to treat moderate to major depression (Barbour et al., 2007). Thus, understanding the underlying mechanisms associated with increasing the intensity of pleasant mood can be beneficial. Mechanisms identified to explain the pleasant effects of exercise on mood include psychological factors, social processes, and physiological factors (Ekkekakis and Petruzzello, 1999; Russell et al., 2003; Schutzer and Graves, 2004). Exercise can increase the intensity of pleasant mood with cardiovascular and weight training (Rocheleau et al., 2004), exercise on a stationary bike or treadmill at a self-selected workload (Rendi et al., 2008), and low-exertion exercise (Netz and Lindor, 2003).
The distractions or surroundings of the exercise setting itself have also been tested as possible factors that may enhance mood during exercise. Listening to music (Hayakawa et al., 2000; Macone et al., 2006), and watching television or reading (Russell et al., 2003) during exercise have been tested as potential factors associated with the increased intensity of pleasant mood during exercise. The extent to which distractions during exercise can enhance pleasant mood is of particular interest to researchers because it could possibly augment (enhance further) the effects of exercise on increasing the intensity of pleasant mood, which could lead to the continuation of a workout routine (Rocheleau et al., 2004).
Yet, while many studies show a consistent pattern of increased pleasant mood following exercise, across multiple sessions and even across a single session (Daley and Welch, 2004; Ekkekakis et al., 2011; Reed and Ones, 2006), there has been inconsistent reporting of how distractions during exercise contribute to pleasant mood changes post-exercise (Berger et al., 2000; Russell et al., 2003). For example, one study showed that exercise enhanced overall mood, as expected, but that including two common distractions during exercise (television watching, reading) did not augment these mood changes more so than exercise alone (Russell et al., 2003). The authors suggested that certain distractors during exercise would be more effective than others at enhancing mood.
In the present study, we examined one possible factor contributing to the effectiveness of distractions on exercise: the enjoyment of the distraction. At present, "distractions" have been treated as standardized, with little effort to identify the extent to which the participants actually enjoy the distraction. For example, participants "watch television" or "read" but the extent to which they desire to do this or the extent to which they enjoy what they are watching or reading has not been identified, despite evidence for increased pleasant mood following more enjoyable activities (Berger, 1996; Wankel, 1993).
Overall, studies show evidence that the more enjoyable an exercise task is to a participant, the more pleasant the mood changes post-exercise (Motl et al., 2000; Raedeke, 2007). We therefore surmised that if an enjoyable exercise activity can enhance mood, then including an enjoyable distraction during a standardize exercise activity could act to augment pleasant mood changes post-exercise. To test this hypothesis, we therefore manipulated the enjoyment of a distraction during exercise, as identified by participants in our study, and compared changes in self-reported affect/mood pre- and post-exercise using an adapted version of the affect grid (Russell et al., 1989).
A sample of 84 undergraduate student volunteers (52 women, 32 men) was recruited through university classroom visits and sign-up sheets. Participant sample characteristics were (M[ + or -] SD) age (19.8 [+ or -] 0.9 years), weight (73 [+ or -] 6.4 kg), height (1.77 [+ or -] 0.05 m), and BMI (24.8 [+ or -] 3.2 kg x [m.sup.-2]). The 84 participants passed an initial screening used to determine if individuals qualified to participate. All participants were light to moderate exercisers (from 0.5 to 1.5 hours of exercise per week), and were nonsmokers who were in general good health with no physical or physician/doctor diagnosed medical conditions including pregnancy, and no dietary or exercise restrictions. Also, all participants ate within the range of 1 to 2 hours prior to the study to control for differences in hunger states, which can otherwise influence changes in affect/mood and arousal (Frank et al., 2010; Privitera et al., 2013).
Measures and equipment
Treadmill: Participants walked on a Life Fitness[R] 95T Inspire TM Treadmill (l x w x h: 2 m x 1 m x 1.5 m) at a standardized walking pace of 3.6 mph for 10 min, which is a sufficient exercise intensity to observe post-exercise changes in mood (Ekkekakis et al., 2000; Hansen et al., 2001). The treadmill had an attached 43 cm LCD television on top of the 18 cm LCD Inspire[TM]...