Hydration and Performance in Young Triathletes During a Competition in Tropical Climate.

PURPOSE: We examined fluid intake, the relation between body mass (BM) loss and performance, and core temperature in young triathletes during a competition in tropical climate. METHODS: Fluid intake and pre and post BM were measured in 35 adolescent athletes, and core temperature was measured in one female and one male. RESULTS: Mean urine specific gravity (1.024 [0.007]) indicated that athletes were in suboptimal state of hydration upon waking. Race time was 73.2 (8.0) minutes. BM decreased by 0.6 (0.3) kg (P < .05). Fluid intake (528.5 [221.6] mL) replaced 47% of the fluid loss (1184.9 [256.4] mL) and was higher during run (11.5 [6.6] mL·min-1) compared to bike (7.3 [3.1] mL·min-1), P < .01. Loss in BM was ≥1.0% in 66% and ≥1.5% in 29% of the athletes. Males showed a moderate association between percentage loss in BM and finishing time (r = -.52), higher sweat rates (1.0 [0.3] L·h-1), and faster times (69.4 [7.5] min; P < .05). Core temperature rose to 40.1 °C in the female and 39.6 °C in the male. CONCLUSION: Young triathletes competing in a hot/humid climate became mildly to moderately dehydrated and hyperthermic even when water and sports drinks were available but did not show symptoms of heat illness.

Sciducio: a practical framework for guiding the development and leadership of the academic research environment.

The goal of this paper is to introduce Sciducio, a practical framework for guiding the development and leadership of an academic research environment. The principal audience for this framework is new academics, that is individuals beginning a tenure-track position in the U.S or a lecturing position elsewhere in the world. However, we also believe this framework will be of use to established academics searching for structure, academics moving to a new institution, and can serve as a training tool for doctoral and postdoctoral mentees. We briefly describe the theory supporting Sciducio, outline the framework and its individual components (blocks), then provide suggested instructions for use. We provide suggested instructions (i.e., descriptive rather than prescriptive), because there is no one-size-fits-all approach for ensuring success. Sciducio incorporates three domains (Plan, Manage, and Deliver), encompasses eight blocks, and is intended to fit on one-sheet of paper or one screen. The Plan domain includes the blocks: value, strategy, and leadership. The Manage domain includes the blocks: activities, key resources, and finances. The Deliver domain includes the blocks: solution and channels. Considering each of the framework blocks is complex, we cannot provide full justice to each component. This paper serves as a general overview and subsequent papers will be more topic specific. Additionally, we encourage others to contribute to and advance this framework.

The relationship between sleep duration and arterial stiffness: A meta-analysis.

Chronically short (<7 h) and long (>9 h) sleep duration may increase cardiovascular disease (CVD) risk relative to the recommended sleep duration (7-9 h). The objective of this study was to evaluate the effects of short and long sleep duration on arterial stiffness, a marker of CVD risk, in adults. Eleven cross-sectional studies were reviewed with a total sample size of 100,050 participants (64.5% male). Weighted mean differences (WMD) and 95% confidence intervals (95% CI) were calculated and pooled using random effects models, and standardized mean differences (SMD) were calculated to determine effect size magnitude. Compared to the recommended sleep duration, both short (WMD = 20.6 cm/s, 95% confidence intervals (CI): 13.8-27.4 cm/s, SMD = 0.02) and long sleep duration (WMD = 33.6 cm/s, 95% CI: 20.0-47.2 cm/s, SMD = 0.79) were associated with higher (detrimental) pulse wave velocity (PWV). The associations between short sleep and higher PWV in adults with cardiometabolic disease, and long sleep and higher PWV in older adults, were also significant in sub-group analysis. These findings indicate short and long sleep duration may contribute to subclinical CVD.

A Cross-Sectional Investigation of Preadolescent Cardiometabolic Health: Associations with Fitness, Physical Activity, Sedentary Behavior, Nutrition, and Sleep.

BACKGROUND: Cardiometabolic disease (CMD) risk often begins early in life. Healthy lifestyle behaviors can mitigate risk, but the optimal combination of behaviors has not been determined. This cross-sectional study simultaneously examined the associations between lifestyle factors (fitness, activity behaviors, and dietary patterns) and CMD risk in preadolescent children. METHODS: 1480 New Zealand children aged 8-10 years were recruited. Participants included 316 preadolescents (50% female, age: 9.5 ± 1.1 years, BMI: 17.9 ± 3.3 kg/m2). Fitness (cardiorespiratory fitness [CRF], muscular fitness), activity behaviors (physical activity, sedentary, sleep), and dietary patterns were measured. Factor analysis was used to derive a CMD risk score from 13 variables (adiposity, peripheral and central hemodynamics, glycemic control, and blood lipids). RESULTS: Only CRF (ß = -0.45, p < 0.001) and sedentary time (ß = 0.12, p = 0.019) were associated with the CMD risk score in the adjusted multivariable analysis. CRF was found to be nonlinear (VO2 max ≤ ≈42 mL/kg/min associated with higher CMD risk score), and thus a CRF polynomial term was added, which was also associated (ß = 0.19, p < 0.001) with the CMD risk score. Significant associations were not found with sleep or dietary variables. CONCLUSION: The findings indicate that increasing CRF and decreasing sedentary behavior may be important public health targets in preadolescent children.

Adiposity in preadolescent children: Associations with cardiorespiratory fitness.

Lifestyle factors contribute to childhood obesity risk, however it is unclear which lifestyle factors are most strongly associated with childhood obesity. The purpose of this cross-sectional study was to simultaneously investigate the associations among dietary patterns, activity behaviors, and physical fitness with adiposity (body fat %, fat mass, body mass index [BMI], and waist to hip ratio) in preadolescent children. Preadolescent children (N = 392, 50% female, age: 9.5 ± 1.1year, BMI: 17.9 ± 3.3 kg/m2) were recruited. Body fat (%) and fat mass (kg) were measured with bioelectrical impedance analysis. Cardiorespiratory fitness (VO2 max), muscular strength (hand-grip strength), activity, sleep, and dietary pattern was assessed. Multivariable analysis revealed that cardiorespiratory fitness associated most strongly with all four indicators of adiposity (body fat (%) (ß = -0.2; p < .001), fat mass (ß = -0.2; p < .001), BMI (ß = -0.1; p < .001) and waist to hip ratio (ß = -0.2; p < .001). Additionally, fruit and vegetable consumption patterns were associated with body fat percentage, but the association was negligible (ß = 0.1; p = 0.015). Therefore, future interventions should aim to promote the use of cardiorespiratory fitness as a means of reducing the obesity epidemic in children.

Exploration of cerebral hemodynamic pathways through which large artery function affects neurovascular coupling in young women.

Background: The interactions between large artery function and neurovascular coupling (NVC) are emerging as important contributors to cognitive health. Women are disproportionally affected by Alzheimer's disease and related dementia later in life. Understanding large artery correlates of NVC in young women may help with preservation of cognitive health with advancing age. Purpose: To explore the association between large artery function, NVC and cognitive performance in young women. Methods: Vascular measurements were made in 61 women (21 ± 4 yrs) at rest and during a cognitive challenge (Stroop task). Transcranial Doppler was used to measure left middle cerebral artery (MCA) maximum velocity (Vmax), mean velocity (Vmean), and pulsatility index (PI). NVC was determined as MCA blood velocity reactivity to the Stroop task. Large artery function was determined using carotid-femoral pulse wave velocity (cfPWV) as a proxy measure of aortic stiffness and carotid ultrasound-derived measures of compliance and reactivity (diameter change to the Stroop task). Cognitive function was assessed separately using a computerized neurocognitive battery that included appraisal of response speed, executive function, information processing efficiency, memory, attention/concentration, and impulsivity. Results: MCA Vmax reactivity was positively associated with executive function (ß = 0.26, 95% CI 0.01-0.10); MCA Vmean reactivity was negatively associated with response speed (ß = -0.33, 95% CI -0.19 to -0.02) and positively with memory score (ß = 0.28, 95% CI 0.01-0.19). MCA PI reactivity was negatively associated with attention performance (ß = -0.29, 95% CI -14.9 to -1.0). Path analyses identified significant paths (p < 0.05) between carotid compliance and carotid diameter reactivity to select domains of cognitive function through MCA reactivity. Conclusions: NVC was associated with cognitive function in young women. Carotid artery function assessed as carotid compliance and carotid reactivity may contribute to optimal NVC in young women through increased blood flow delivery and reduced blood flow pulsatility.

Central Blood Pressure and Subclinical Atherosclerotic Risk in Young Hispanic American Women.

BACKGROUND: The incidence of younger women being hospitalized from cardiovascular disease (CVD) events is on the rise. Hispanic women are generally thought to have higher CVD risk factor burden than non-Hispanic White (NHW) women yet Hispanic Americans have lower mortality from CVD. Traditional measures of CVD may not accurately capture CVD risk in Hispanic Americans. Hence, the purpose of this study was to assess the impact of ethnicity on vascular reactivity and central hemodynamic load to gain insight into subclinical CVD risk in young women. METHODS: Brachial flow-mediated dilation (FMD), low-flow mediated constriction (L-FMC), carotid-femoral pulse wave velocity (cfPWV), and pulse wave analysis (from synthesized aortic pressure waveforms) were measured in 25 Hispanic women and 31 NHW women aged between 18-35 years. FMD and L-FMC were combined to provide an index of total vessel reactivity. RESULTS: NHW and Hispanic women did not differ in age or traditional CVD risk factors (P>.05 for all). Compared with NHW women, Hispanic women had greater vascular reactivity (8.7±4.1 vs 11.7±4.1 %, P=.011), lower central pulse pressure (28±5 vs 24±3 mm Hg, P=.001) and lower pressure from wave reflections (12±2 vs 10±1 mm Hg, P=.001). There were no differences in cfPWV between NHW women and Hispanic women (5.4±0.7 vs 5.3±0.7 m/s, P=.73). CONCLUSION: Young Hispanic women have greater vascular reactivity and lower central pulsatile hemodynamic load compared with NHW women, suggesting lower subclinical CVD risk.

Targeting Sedentary Behavior in Minority Populations as a Feasible Health Strategy During and Beyond COVID-19: On Behalf of ACSM-EIM and HL-PIVOT.

Increased sedentary behavior has been an unintended consequence of social and physical distancing restrictions needed to limit transmission of SARS-CoV-2, the novel coronavirus that causes COVID-19. Sedentary behavior is defined as any waking behavior characterized by an energy expenditure ≤1.5 metabolic equivalents (METs), while in a sitting, reclining, or lying posture. These restrictions negatively impact peoples' cardiometabolic and mental health and disproportionately affect certain sectors of the population, including racial/ethnic minorities. In part, the higher risk for complications of COVID-19 could be the result of increased prevalence of comorbid diseases. Further, regular participation and adherence to current physical activity guidelines, defined as at least 150 minutes per week of moderate intensity physical activity or muscle strengthening activities on 2 or more days a week, is challenging for many and may be especially difficult to achieve during the COVID-19 pandemic. A practical strategy to promote health and well-being during COVID-19 is reducing sedentary behavior. Reducing sedentary behaviors (e.g., breaking up periods of prolonged sitting with light-intensity physical activity) may be more easily achieved than physical activity for all individuals, including individuals of racial/ethnic decent, as it does not require purchasing equipment nor require compromising the physical restrictions necessary to slow the spread of COVID-19. The purpose of this commentary is to argue that sedentary behavior is a feasible, independent target to modify during COVID-19, particularly in minority populations, and to address this behavior we need to consider individual, environmental and policy-level factors.