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[This corrects the article DOI: 10.1371/journal.pone.0198390.].

American Indians (AI) have high prevalence of diabetes in youth and may benefit from increasing physical activity as a strategy to improve metabolic health. We tested whether financial incentives would elicit greater frequency and/or duration of exercise in AI youth at high risk for developing diabetes. Overweight/obese AI boys and girls, 11-20 years old, were instructed to exercise on 3 days/week for 48 weeks at a tribal wellness center. The program was divided into three, 16-week-long phases to test different financial incentive strategies. Within each phase participants were randomly assigned to one of two groups that received different payments for exercise. Phase 1 was designed to test whether the size of the incentive would affect exercise frequency. In Phase 1, the number of exercise sessions did not differ between the group receiving a modest fixed-value payment per exercise session and the group receiving enhanced incentives to exercise more frequently (26 ± 3 versus 28 ± 2 sessions, respectively, p = 0.568). In Phase 2, the provision of an enhanced financial incentive to increase exercise duration resulted longer sessions, as the incentivized and standard payment groups exercised 38 ± 2 versus 29 ± 1 minutes per session (p = 0.002), respectively. In Phase 3, the effect of reducing the incentives on maintenance of exercise behaviors was inconclusive due to high participant withdrawal. Aerobic fitness increased 10% during Phase 1 but was unchanged thereafter. Insulin sensitivity and body composition were unchanged during the study. In conclusion, enhanced financial incentives increased the duration of exercise sessions, but had minimal effects on exercise participation. These results indicate that financial incentives hold promise in motivating previously sedentary, overweight/obese adolescents to exercise longer, but motivating them to sustain an exercise program remains the major challenge.Trial registrationClinicalTrials.gov NCT01848353.

The incidence of skin cancer is rising among American Indians (AI) but the prevalence of harmful ultraviolet light (UVL) exposures among AI youth is unknown. In 2013, UVL exposures, protective behaviors, and attitudes toward tanning were assessed among 129 AI and Non-Hispanic (NHW) students in grades 8–12 in Southeastern Oklahoma. Sunburn was reported by more than half the AI students and most of the NHW students. One-third of AI students reported never using sunscreen, compared to less than one-fifth of NHW students, but racial differences were mitigated by propensity to burn. Less than 10% of students never covered their shoulders when outside. Girls, regardless of race, wore hats much less often than boys. Regardless of race or sex, more than one-fourth of students never stayed in the shade, and more than one-tenth never wore sunglasses. The prevalence of outdoor tanning did not differ by race, but more than three-fourths of girls engaged in this activity compared to less than half the boys. Indoor tanning was reported by 45% of the girls, compared to 20% of girls nationwide, with no difference by race. Nearly 10% of boys tanned indoors. Among girls, 18% reported more than ten indoor tanning sessions. Over one-quarter of participants agreed that tanning makes people look more attractive, with no significant difference by race or sex. Investigations of UVL exposures should include AI youth, who have not been represented in previous studies but whose harmful UVL exposures, including indoor tanning, may place them at risk of skin cancer.