Association of cardiorespiratory fitness and adiposity with inflammatory biomarkers in young adults.

OBJECTIVES: Cardiorespiratory fitness (fitness) has been inversely associated with inflammation, but whether the association is attributed to fitness itself or lower levels of adiposity remains uncertain in young adults. The purpose of this study was to determine the association of fitness and adiposity with inflammation in young adults. METHODS: A cross-sectional study was conducted with 88 participants aged 20-34 years. Fitness was assessed by a submaximal treadmill walking test. Adiposity was assessed by body mass index (BMI) and waist circumference (WC). Inflammation was measured by plasma C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) levels using immunoassays. Biological data were log10 transformed. A separate multiple regression analysis was conducted with each inflammatory biomarker as a dependent variable. Covariates (sex, oral contraceptive use, and education level) were adjusted. RESULTS: Fitness was inversely associated with log10 CRP after adjustment for covariates but not after adjusting for BMI or WC. Fitness was inversely associated with log10 IL-6 after adjustment for WC and covariates (ß = -0.341, P = .049) but not after adjusting for BMI. Fitness × WC interaction (partial eta2 = 0.056, P = .033) indicated that high fitness was more strongly associated with low log10 IL-6 in young adults with high WC than those with low WC. CONCLUSIONS: Although adiposity has a stronger association than fitness with CRP and IL-6, higher levels of fitness could be essential for maintaining low levels of IL-6, especially in the presence of high levels of central adiposity.

Engagement in Physical Activity Among Young Adult Childhood and Adolescent Cancer Survivors: Integration of Nature Technology.

This report addresses physical activity (PA) levels and education preferences in young adult cancer survivors (YACS) and outlines strategies for the design of successful interventions. A cross-sectional design was used to assess PA in 124 YACS, using the International Physical Activity Questionnaire-Short Form. Recommended levels were reported by 20.2% and 42.5% for high and moderate PA in metabolic equivalent of task (MET) minutes/week, respectively, while 37.3% reported low level PA in MET-minutes/week. Eighty percent reported likely to use technology for education about PA. Prior research supports using technology to administer tailored interventions to promote consistent PA among YACS, ideally in nature-based activities.

Cardiorespiratory fitness, adiposity, and ambulatory blood pressure in adolescents.

BACKGROUND: This study examined the association of cardiorespiratory fitness (fitness) and adiposity (Body Mass Index [BMI] and waist circumference [WC]) with ambulatory blood pressure (ABP) and tested the moderating effect of adiposity on the association between fitness and ABP. METHODS: A cross-sectional study was conducted with 370 adolescents aged 11-16 years. Fitness was assessed by a height-adjusted step test and estimated by heart rate recovery, defined as the difference between peak heart rate during exercise and heart rate two minutes postexercise. Adiposity was measured using dichotomized values for percentiles of BMI (≥85th) and WC (≥50th). ABP was measured every 30-60 minutes over 24 hours on a school day. Mixed-effects regression analysis was used. RESULTS: Each unit increase in fitness was associated with a decrease of systolic blood pressure (SBP) [-0.058 mmHg, P=0.001] and diastolic blood pressure (DBP) [-0.043 mmHg, P<0.001] after adjustment for WC and covariates. Each unit increase in fitness was associated with a decrease in SBP [-0.058 mmHg, P=0.001] and DBP [-0.045 mmHg, P<0.001] after adjustment for BMI and covariates. Fitness and BMI≥85th percentile (or WC ≥ 50th percentile) interactions were not associated with ABP after adjustment for covariates. CONCLUSIONS: Our findings indicate a small but statistically significant inverse effect of fitness on ABP in adolescents. No evidence of a modifying effect of adiposity on this association suggesting that fitness and weight management have essential roles for maintaining lower ABP in adolescents.