Active Voice: Get Fit or Get Hit!
By Laura Chaddock

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.

Laura Chaddock is a research scientist and Ph.D. candidate in Cognitive Neuroscience at the Beckman Institute for Advanced Science and Technology at the University of Illinois in Urbana-Champaign. She uses structural and functional magnetic resonance imaging (MRI) techniques to study the role of aerobic fitness and physical activity in cognitive and brain health across the lifespan. As a fitness enthusiast, she lives what she studies. This commentary presents Ms. Chaddock’s views associated with a research article related to this commentary topic, which she and her colleagues published in the April 2012 issue of Medicine & Science in Sports & Exercise® (MSSE).

We live in a fast-paced, multitasking world where daily situations require efficient processing of environmental stimuli and attention to concurrent tasks. Street crossing is a multitask challenge. To successfully cross a street, pedestrians need to simultaneously attend to the flow of traffic, monitor and remember vehicle distances and speeds, and execute a crossing.

Street crossing is especially dangerous for children. Pedestrian accidents are the second leading cause of injury and mortality in children between the ages of five and 14. Thus, there is a growing initiative to find strategies that improve child pedestrian safety.

Does fitness play a role in childhood street crossing abilities? Recently, in a review of research in our lab and elsewhere, we summarized evidence supporting that increased physical activity and aerobic fitness during childhood are associated with superior brain health. Children with higher aerobic fitness levels show improved academic achievement and cognitive abilities, coupled with larger brain structures and more efficient brain function. Perhaps the performance benefits for higher-fit children in the laboratory and in school extend to a realistic multitask challenge such as street crossing.

To test this idea, and as reported in our April MSSE research article, we recruited 13 higher-fit children and 13 lower-fit children, ages 8-10. Children completed a treadmill test to measure their aerobic fitness. Higher-fit (>70th percentile of VO2 max) and lower-fit (<30th percentile of VO2 max) fitness groups were created. The groups were matched in terms of age, gender, IQ, pubertal timing, and socioeconomic status.

A street intersection was modeled in an immersive virtual reality environment, and higher-fit and lower-fit children used their traffic-dodging skills as they walked on a manual treadmill that was integrated with the virtual world. Cars drove by at 22 miles per hour on a two-lane road, and the participants were told to walk across the virtual road when they thought it was safe. Large viewing screens surrounded the treadmill, and participants wore goggles that provided depth and realism. The children attempted to cross the street while undistracted, as well as while conversing on a cellular phone or listening to music on an iPod -- in essence, creating tasks that might introduce additional multitask challenges. Using technological devices has become a widespread practice with young children.

As predicted, we found that differences in aerobic fitness impacted street crossing success rates. Higher-fit children maintained street crossing performance across all levels of distraction. Lower-fit children showed decreased crossing success rates when conversing on the phone, relative to the undistracted and music task conditions. Together, the results suggest that higher levels of aerobic fitness may play a role in attenuating the impairment typically associated with multitasking in real-world tasks, such as street crossing.

Further, the results do not suggest that the performance differences were a result of higher-fit children being speedier on the treadmill. Higher-fit children did not walk faster than lower-fit students. Thus, cognitive benefits in higher-fit children, rather than street crossing speed, may have contributed to differences in success rates on the street crossing paradigm.

Our findings arrive at an important time. Physical activity opportunities in schools are being reduced, and childhood sedentary behaviors are increasing. The study suggests childhood aerobic fitness not only relates to performance in the classroom and laboratory; it may also extend to childhood pedestrian-automobile accidents and, perhaps more generally, multitasking.

A final note: Please tell children to put away cell phones while navigating roadways. No amount of fitness training makes walking and talking in traffic a wise move. All children were involved in more simulated collisions in our study when chatting on the phone relative to when undistracted or listening to music. Perhaps, by encouraging children to stay fit and focused, we can help them stay healthy and safe.