A Theory-Informed, Personalized mHealth Intervention for Adolescents (Mobile App for Physical Activity): Development and Pilot Study

in JMIR Formative Research (2022), 6(6), 35118

Background: Evidence suggests that physical activity (PA) during childhood and adolescence is crucial as it usually results in adequate PA levels in adulthood. Given the ubiquitous use of smartphones by ... [more ▼]

Background: Evidence suggests that physical activity (PA) during childhood and adolescence is crucial as it usually results in adequate PA levels in adulthood. Given the ubiquitous use of smartphones by adolescents, these devices may offer feasible means to reach young populations and deliver interventions aiming to increase PA participation and decrease sedentary time. To date, very few studies have reported smartphone-based interventions promoting PA for adolescents. In addition, most available fitness apps do not include the latest evidence-based content. Objective: This paper described the systematic development of a behavior change, theory-informed Mobile App for Physical Activity intervention with personalized prompts for adolescents aged 16 to 18 years. The within-subject trial results provided the first evidence of the general effectiveness of the intervention based on the outcomes step count, sedentary time, and moderate to vigorous PA (MVPA) minutes. The effectiveness of the intervention component personalized PA prompt was also assessed. Methods: A 4-week within-subject trial with 18 healthy adolescents aged 16 to 18 years was conducted (mean age 16.33, SD 0.57 years). After the baseline week, the participants used the Mobile App for Physical Activity intervention (Fitbit fitness tracker+app), which included a daily personalized PA prompt delivered via a pop-up notification. A paired 1-tailed t test was performed to assess the effectiveness of the intervention. Change-point analysis was performed to assess the effectiveness of a personalized PA prompt 30 and 60 minutes after prompt delivery. Results: The results showed that the intervention significantly reduced sedentary time in adolescents during the first week of the trial (t17=−1.79; P=.04; bootstrapped P=.02). This trend, although remaining positive, diminished over time. Our findings indicate that the intervention had no effect on metabolic equivalent of task–based MVPA minutes, although the descriptive increase may give reason for further investigation. Although the results suggested no overall change in heart rate–based MVPA minutes, the results from the change-point analyses suggest that the personalized PA prompts significantly increased heart rate per minute during the second week of the study (t16=1.84; P=.04; bootstrapped P=.04). There were no significant increases in participants’ overall step count; however, the personalized PA prompts resulted in a marginally significant increase in step counts per minute in the second week of the study (t17=1.35; P=.09; bootstrapped P=.05). Conclusions: The results of the trial provide preliminary evidence of the benefit of the Mobile App for Physical Activity intervention for modest yet significant reductions in participants’ sedentary time and the beneficial role of personalized PAprompts. These results also provide further evidence of the benefits and relative efficacy of personalized activity suggestions for inclusion in smartphone-based PA interventions. This study provides an example of how to guide the development of smartphone-based mobile health PA interventions for adolescents. [less ▲]

The effects of physical activity on emotion regulation in adolescents

Scientific Conference (2016, February 27)

A growing body of evidence suggests an important contribution of physical activity to psychological well-being. While much of this research has focused on mood, less is known regarding emotion regulation ... [more ▼]

A growing body of evidence suggests an important contribution of physical activity to psychological well-being. While much of this research has focused on mood, less is known regarding emotion regulation. The present study investigated acute and chronic effects of exercise on responses to emotional stimuli in adolescents. Male and female students (N=40) aged 15-18 years participated in a two conditions, repeated-measures, fully counterbalanced design. In the first part of each session heart rate, electrodermal activity, respiration rate and heart rate variability were continuously recorded during a 10-min baseline. This was followed by a previously validated anger-provoking video-clip lasting 2-6 minutes. Participants rated the level of arousal and discrete emotions they experienced in response to the clip. The second part of the experiment consisted of a 30 minutes intervention period (rest or stationary cycling), immediately followed by another video-clip and questionnaire. The ongoing data analysis consists of (1) comparisons between conditions (acute effects) and (2) analyses of covariance regarding the physiological changes in response to the emotional stimuli, with participants’ fitness level used as a covariant (chronic effects). Preliminary results indicate that in the exercising condition, participants reported significantly lower levels of arousal, anxiety, anger, surprise and disgust, compared with the resting condition (p≤0.05). In contrast, fear, shame, sadness, and calmness did not differ between conditions. Further analyses will reveal whether participants’ physical fitness and heart rate variability had an impact on their physiological and psychological reactivity to the negative emotional stimuli. [less ▲]

Elicitation of Negative Emotions in Adolescents using Video Clips

Poster (2014, September 05)

Thermal sensitivity to warmth during rest and exercise: a sex comparison

in European Journal of Applied Physiology (2014)

Reduction in thermal sensitivity to cold during post-exercise recovery

Poster (2012, July)

Effects of ethnicity on thermal sensitivity to cold

Scientific Conference (2012)

Regional Variations in sensitivity to cold at rest and during exercise

in Fourteenth International Conference on Environmental Ergonomics (2011)