Influence of running on incidental and integral vitality and fatigue: An intensive longitudinal intervention in young Women's daily life.

Exercise intensity and perceived autonomy are important factors for the affective response toward exercise and adherence. Dual-mode theory suggests an inverted-J response curve of affect with increased exercise intensity, but little is known about how different running programs affect the affective response and subsequent incidental affect in daily life. This ambulatory assessment study examines the short- to long-term effects of two 8-week running interventions (affect-based vs. polarized-prescribed) on subjective vitality and perceived fatigue in young female novices. Participants engaged in 3 × 30 minute running sessions weekly in their natural environments and completed electronic diaries three times daily. Autoregressive multilevel models indicate small effects of training intensity on immediate affective subjective vitality (ß = -2.37; p = .03; f2 = 0.02) but negligible non-significant effects on fatigue (ß = 0.26; p = 0.12; f2 = 0.002). Novices experienced increased vitality throughout the day when their running was evaluated positively (ß = 0.23; p = .03; f2 = 0.04), with effects lasting over two days before returning to baseline (ß = -0.26; p < .001; f2 = 0.004). However, no significant long-term effects were observed over 8 weeks in vitality or fatigue. Results indicate between- and within-person variations, but limited sample power does not allow differentiating between programs. This study supports the dual-mode theory and highlights the importance of distinguishing affective response from incidental affect.