Happy trails: the effect of a media campaign on urban trail use in southern Nevada.

Background: Many Americans do not meet recommendations for physical activity (PA). Communities are building trail networks to encourage PA, but the relationship between trails and PA is not well understood.

Methods: We monitored usage of urban trails (N = 10) in Las Vegas, NV, before and after a promotional marketing campaign (October 2011 and April 2012).

Environmental and social determinants of youth physical activity intensity levels at neighborhood parks in Las Vegas, NV.

Parks can play an important role in youth activity. This study used observational data to evaluate the relationship of environmental and social determinants to youth physical activity intensity levels in Las Vegas neighborhood parks. System for observing play and leisure activity in youth was used to code activity levels as sedentary, walking, or vigorous in five low-income and five high-income parks.

Adolescent gender and ethnicity differences in physical activity perceptions and behavior.

Objectives: To examine gender and ethnicity differences in adolescents' physical activity (PA) behavior and perceptions.

Methods: Surveys designed to measure PA behavior and perception were completed by 175 adolescents. Gender and ethnicity differences in PA behavior were examined using chi-square tests.