This study used a daily diary approach to examine associations between day-level physical activity (PA) behavior, PA-specific motivational profile, and days since the COVID-19 national emergency declaration during the early months (April-June 2020) of the pandemic. A total of 468 US adults (Mage = 34.8 y, 79% female) participated in a 28-day smartphone-based daily diary study assessing PA. A baseline survey assessed PA and motivation for PA using the Behavioral Regulation in Exercise Questionnaire. Multilevel linear regression models examined the main effects and interactions of motivational profile and time (days since the US March 13, 2020, COVID-19 national emergency declaration) on daily PA minutes. Latent profile analysis identified 4 distinct motivational profiles for PA among this sample: profile 1: high amotivation (n = 100, 21%); profile 2: low controlled motivation (n = 55, 12%); profile 3: high external regulation (n = 47, 10%); and profile 4: moderate autonomous motivation (n = 266, 57%). After controlling for baseline PA, there were significant interactions between profile and time on daily PA (-0.21, P < .01). Profile 2 showed greater decreases in daily PA minutes over time than profile 1 (b = -0.29, P < .01). Profiles 3 and 4 did not indicate significant decreases in PA compared with profile 1 (b = 0.14, P = .31 and b = -0.16, P = .05, respectively). Contrary to previous research, individuals with lower controlled or moderate autonomous motivation demonstrated the largest decreases in PA over time, whereas individuals with higher amotivation or external regulation demonstrated smaller decreases over time. These findings suggest that external motivation may have provided short-term protection against declines in PA observed during early months of the COVID-19 pandemic.
Keywords: ecological momentary assessment; health behavior; lockdown.