Racial/ethnic disparities in access to social and environmental supports for physical activity (PA) exist at each level of Bronfenbrenner’s ecological-systems model. African American and Latino youth are less likely to have PA equipment at home, more likely to have access to electronic-media devices, and more likely to attend schools with insufficient PA programming (microsystem). Parents of African American and Latino youth tend to have lower involvement at schools, resulting in fewer opportunities to provide social support for their children’s PA (mesosystem). African American and Latino youth also lack safe places to exercise in their neighborhoods (exosystem) and may experience socioeconomic and cultural barriers to engaging in PA (macrosystem). Yet, there are vast opportunities to intervene—policy approaches, developing school- and family-based programming, and altering the built environment can foster the adoption and maintenance of health-enhancing PA in ethnic-minority youth. This review highlights prominent disparities in PA supports for African American and Latino children and adolescents, as well as current strategies used to reduce disparities in youth PA.
Matthew Nagy, Molly O’Sullivan, Shannon Block, and Rebecca E. Hasson
Purpose: To investigate the acute effects of intermittent activity performed at varying intensities on the perceptions of exercise-related fatigue in children. Methods: A total of 30 children completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary breaks. The perceptions of exercise-related fatigue were determined via the Subjective Exercise Experience Scale at the beginning (0 breaks), middle (after 10 breaks), and end (after 20 breaks) of each condition. Results: The average heart rate was significantly higher with increasing exercise intensity (sedentary: 89.6 ± 1.2 beats/min, low: 114.6 ± 1.8 beats/min, moderate: 147.2 ± 1.8 beats/min, and high: 172.3 ± 1.8 beats/min, P < .0001). There was no significant main effect of condition (sedentary: −0.5 ± 0.6, low: −1.0 ± 0.7, moderate: −0.2 ± 0.5, and high: −0.6 ± 1.2; P = .86) and time (10–0 breaks: −0.7 ± 0.5 and 20–0 breaks: −0.5 ± 0.5; P = .45), nor time by condition interaction (P = .99) on change in exercise-related fatigue. Conclusions: Incorporating intermittent activity into physical activity programs may help to reduce barriers to regular exercise by minimizing perceptions of exercise-related fatigue in children.
Rebecca E. Hasson, Kirsten E. Granados, David Xavier Marquez, Gary Bennett, Patty Freedson, and Barry Braun
Racial differences in psychological determinants of exercise exist between non-Hispanic blacks (blacks) and non-Hispanic whites (whites). To date, no study has examined racial differences in the psychological responses during and after exercise. The objective of this study was to compare psychological outcomes of single exercise bouts in blacks and whites.
On 3 separate occasions, sedentary black (n = 16) and white (n = 14) participants walked on a treadmill at 75%max HR for 75 minutes. Questionnaires assessing mood, state anxiety, and exercise task self-efficacy were administered before and after each exercise bout. In-task mood and rating of perceived exertion (RPE) were measured every 5 minutes during exercise.
Exercise self-efficacy and psychological distress significantly improved in both blacks and whites. However during exercise blacks reported more positive in-task mood and lower RPE compared with whites.
These data suggest that racial differences exist in psychological responses during exercise. Further research should confirm these findings in a larger, free-living population.
Emma Weston, Matthew Nagy, Tiwaloluwa A. Ajibewa, Molly O’Sullivan, Shannon Block, and Rebecca E. Hasson
Purpose: To compare the acute effects of intermittent physical activity (PA) across 4 different intensities on blood pressure. Methods: Thirty children (12 males and 18 females; aged 7–11 y; 33% overweight/obese; 53% nonwhite) completed 4 experimental conditions in random order: 8 hours sitting interrupted with 20, 2-minute low-, moderate-, high-intensity PA breaks, or sedentary screen-time breaks. PA intensity corresponded with 25%, 50%, and 75% of heart rate reserve. Blood pressure was measured during each condition in the morning (0800 h), noon (1200 h), and afternoon (1600 h). Results: There were no significant differences across conditions for systolic blood pressure (SBP; all Ps > .05). There was a significant effect of time with SBP decreasing throughout the day for all conditions (average morning SBP: 106  mm Hg, average noon SBP: 101  mm Hg, average afternoon SBP: 103  mm Hg; P = .01). There were no significant effects of condition or time on diastolic blood pressure (all Ps > .05). Conclusion: While sedentary behavior is known to be associated with hypertension in both adults and children, a single bout of prolonged sitting may be insufficient to produce hypertensive effects in otherwise healthy children. Future research should examine the appropriate dose of intermittent PA to accrue hypotensive responses in preadolescent children.
Matthew R. Nagy, Molly P. O’Sullivan, Shannon S. Block, Trevor R. Tooley, Leah E. Robinson, Natalie Colabianchi, and Rebecca E. Hasson
Background: The purpose of this study was to examine the acute effects of intermittent physical activity (2-min bouts of varying intensities) on psychological mood and enjoyment in elementary school-age children and to examine the effect of weight status on these psychological outcomes. Methods: A total of 39 children (healthy weight, n = 26; overweight/obese, n = 13) completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute screen-time breaks. Mood was assessed using the Feeling Scale immediately following each break. Enjoyment was assessed using the Physical Activity Enjoyment Scale immediately following 10 and 20 breaks. Results: Mood was significantly higher during the sedentary versus active conditions (P < .01). Overweight/obese children reported lower mood scores compared with healthy weight children at the initiation of the low- (P < .05) and high-intensity conditions (P < .001) but experienced improvements in mood throughout the day in all 3 active conditions (P = .02). Enjoyment was significantly higher after completing the active versus sedentary conditions (P = .02). Conclusion: These findings suggest that both healthy weight and overweight/obese children felt better immediately after engaging in screen-time breaks but subsequently rated the activity breaks as more enjoyable compared with screen-time breaks.
Molly P. O’Sullivan, Matthew R. Nagy, Shannon S. Block, Trevor R. Tooley, Leah E. Robinson, Natalie Colabianchi, and Rebecca E. Hasson
Purpose: The purpose of this study was to compare the effects of intermittent activity performed at varying intensities and of prolonged sitting on physical activity compensation. Methods: A total of 33 children (14 boys and 19 girls; age 7–11 y; 24% overweight/obese; 61% nonwhite) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary computer game breaks. Physical activity energy expenditure (PAEE) was assessed via accelerometry to establish baseline PAEE and throughout each condition day (8-h in-lab PAEE, out-of-lab PAEE, and 3-d postcondition). Results: Compared with baseline PAEE, total daily PAEE was significantly higher during the high-intensity condition day (153 ± 43 kcal, P = .03), unchanged during the low-intensity (−40 ± 23 kcal, P > .05) and moderate-intensity condition days (−11 ± 18 kcal, P > .05), and decreased in response to prolonged sitting (−79 ± 22 kcal, P = .03). There were no significant differences in PAEE 3-day postcondition across conditions (P > .05). Conclusion: Despite the varying levels of PAEE accumulated during the 8-hour laboratory conditions, out-of-lab PAEE during each condition day and 3-day postcondition did not change from the baseline. These findings provide preliminary evidence that spontaneous physical activity in children does not change in response to intermittent activity or prolonged sitting.
Shannon S. Block, Trevor R. Tooley, Matthew R. Nagy, Molly P. O’Sullivan, Leah E. Robinson, Natalie Colabianchi, and Rebecca E. Hasson
Purpose: The purpose of this study was to compare the acute effects of video game breaks and intermittent exercise breaks, performed at varying intensities, on math performance in preadolescent children. Methods: A total of 39 children (18 males and 21 females; aged 7–11 y) completed 4 experimental conditions in random order: 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity exercise breaks or 20 two-minute sedentary computer game breaks. The intensity of exercise breaks for the low-, moderate-, and high-intensity conditions corresponded with 25%, 50%, and 75% of heart rate reserve, respectively. Math performance was assessed 3 times throughout each condition day using a 90-second math test consisting of 40 single-digit addition and subtraction questions. Results: There were no significant differences in percent change in math scores (correct answers out of attempted) by condition [low: −1.3 (0.8), moderate: 0.1 (1.3), high: −1.8 (0.7), and computer: −2.5 (0.8); P > .05]. There were significant differences in percent change in math scores over the course of the condition days with lower math scores reported at end-of-day test compared with midday test [−2.4 (0.5) vs −0.4 (0.3); P = .01]. There were no significant condition × time, time × age, condition × age, or condition × time × age interactions (all Ps > .05). Conclusion: Action-based video game and exercise breaks elicit the same level of math performance in children; however, time of day may impact this relationship. These findings may have important implications for instructional time in elementary classrooms.