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The effect of the menstrual cycle on fluid balance during physical work in the heat when fluids are freely available is unknown. This study demonstrates that fluid balance is not modified in women across three distinct phases of the menstrual cycle during physical work in the heat These results indicate that when women have free access to cool fluid during physical work in the heat, they respond similarly across all three phases to maintain fluid homeostasis across the menstrual cycle.

Activity-related energy expenditure (AEE) correlates with physical activity volume; however, between-person differences in body size and walking economy (net V̇o2) can influence AEE. The ratio of total energy expenditure (TEE) and resting energy expenditure (REE) estimates physical activity level (PAL) relative to body mass, yet does not account for variance in walking economy. The activity-related time equivalent (ARTEwalk) circumvents such constraints by adjusting for individual-specific walking economy. Herein, we compared AEE, PAL, and ARTEwalk index in a cohort ( n = 81) of postmenopausal women while examining possible associations with biomarkers of cardiometabolic health. Secondary analyses were performed on postmenopausal women dichotomized above/below age group 50th percentile for body fat percent. TEE was reduced by 10% for the thermogenesis of digestion wherein AEE was calculated by subtracting REE from adjusted TEE. PAL was calculated as the ratio of TEE/REE. AEE was divided by the mean net energy expenditure of nongraded walking to calculate the ARTEwalk index. Between-group differences were not detected for AEE or PAL. However, the ARTEwalk index revealed that participants with less adiposity were more physically active (258 ± 149 vs. 198 ± 115 min·day−1; P = 0.046; g = 0.46). AEE and PAL did not correlate with cardiorespiratory fitness or biomarkers of cardiometabolic health. Cardiorespiratory fitness ( r = 0.32), arterial elasticity ( r = 0.24), total cholesterol/HDL-c ratio ( r = −0.22), and body fat% ( r = −0.24) were correlated with ARTEwalk. The ARTEwalk index may offer utility in detecting possible differences in physical activity volume among postmenopausal women and appears better associated with cardiometabolic biomarkers compared with AEE or PAL.

PURPOSE: Aging associated with progressive declines in physical function is well-known; however, little is known about the trajectories of physical function before and after breast cancer diagnosis. The current study examined the trajectories in objective measures of physical function over 20 years for women with breast cancer and matched controls. METHODS: 2712 community-dwelling women (452 breast cancer cases and 1:5 matched cancer-free controls) aged 65 years or older at baseline (1986-1988) within the Study of Osteoporotic Fractures were followed for 20 years. Objective physical function was assessed up to 9 times, including hand-grip strength, timed chair stand, gait speed and quadriceps strength. Linear mixed models were used to model physical function changes in terms of secular time trend, group (cases or controls), period (pre-and post-diagnosis status), and their interaction terms. RESULTS: We observed all measures of physical function declined over time. While no differences in trends between cases and controls during the pre-diagnosis period were observed, after cancer diagnosis, grip strength and gait speed declined significantly faster in cases than controls. Quadriceps strength significantly decreased ~7 pounds shortly after breast cancer diagnosis, and then improved over time. CONCLUSION: Our prospective study revealed that older breast cancer survivors had significantly worse declines in grip strength and gait speed and a sharp, short-term drop followed by gradual improvement over time in quadriceps strength, compared to women without cancer. These findings suggest exercise training targeting muscle strength and mobility would be beneficial among older breast cancer survivors.

NEW FINDINGS: What is the central question of this study? Are chronotropic responses to a 6-minute walk test different in women with post-acute coronavirus disease 2019 (COVID-19) syndrome compared with control subjects? What is the main finding and its importance? Compared with control subjects, the increase in heart rate was attenuated and recovery delayed after a 6-minute walk test in participants after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Women reporting specific symptoms at time of testing had greater impairments compared with control subjects and SARS-CoV-2 participants not actively experiencing these symptoms. Such alterations have potential to constrain not only exercise tolerance but also participation in free-living physical activity in women during post-acute recovery from COVID-19. ABSTRACT: The short-term cardiopulmonary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well defined. However, the implications of cardiopulmonary sequelae, persisting beyond acute illness, on physical function are largely unknown. Herein, we characterized heart rate responses to and recovery from a 6-minute walk test (6MWT) in women ∼3 months after mild-to-moderate SARS-CoV-2 infection compared with non-infected control subjects. Forty-five women (n = 29 SARS-CoV-2; n = 16 controls; age = 56 ± 11 years; body mass index = 25.8 ± 6.0 kg/m2 ) completed pulmonary function testing and a 6MWT. The SARS-CoV-2 participants demonstrated reduced total lung capacity (84 ± 8 vs. 93 ± 13%; P = 0.006), vital capacity (87 ± 10 vs. 93 ± 10%; P = 0.040), functional residual capacity (75 ± 16 vs. 88 ± 16%; P = 0.006) and residual volume (76 ± 18 vs. 93 ± 22%; P = 0.001) compared with control subjects. No between-group differences were observed in 6MWT distance (P = 0.194); however, the increase in heart rate with exertion was attenuated among SARS-CoV-2 participants compared with control subjects (+52 ± 20 vs. +65 ± 18 beats/min; P = 0.029). The decrease in heart rate was also delayed for minutes 1-5 of recovery among SARS-CoV-2 participants (all P

Numerous elements of the COVID-19 pandemic have proven challenging to overcome. We now recognize a perplexing characteristic of SARS-CoV-2 features mixed, unresolving symptoms that can last 4 weeks or longer after initial diagnosis, termed post-acute sequelae of SARS-CoV-2 (PASC). Full recovery can thus become a protracted ordeal as conservative estimates indicate 20% of SARS-CoV-2 cases will develop PASC, with women at increased risk. Emerging evidence suggests latent virus reactivation including cytomegalovirus, Epstein-Barr virus, and/or varicella zoster virus may perpetuate the burden of PASC. This is problematic because immune dysfunction is linked to obesity and psychological stress, both of which disproportionately affect socioeconomically disadvantaged people and racial/ethnic minorities. Applying a patient-centered approach in which the principal factors guiding decision-making are based on the needs and abilities of the individual is essential. Still, the independent and combined influence of obesity and psychological stress on immune function necessitates due consideration in the context of PASC recovery.

Hunter, GR, Singh, H, Martins, C, Baranauskas, MN, and Carter, SJ. Stretch-shortening cycle potentiation and resistance training-induced changes in walking economy/ease and activity-related energy expenditure in older women. J Strength Cond Res 35(5): 1345-1349, 2021-Use of elastic energy to improve economy and ease of walking may be important for older adults. The purpose of this investigation was to determine whether baseline (i.e., untrained) stretch-shortening cycle potentiation (SSCP) was associated with potential changes in free-living activity-related energy expenditure (AEE) after supervised exercise training. Sedentary, postmenopausal women (n = 64) between 60 and 74 years of age were evaluated before and after 16 weeks of combined aerobic and resistance training. Assessments included: (a) body composition (dual-energy X-ray absorptiometry), (b) resting energy expenditure (indirect calorimetry), (c) submaximal and maximal walking (treadmill/indirect calorimetry), (d) total energy expenditure (doubly labeled water), and (e) one repetition maximum performed on an incline leg press and SSCP (calculated as the difference between concentric and countermovement leg press throw). Results indicated that baseline SSCP was related (r = -0.29; p < 0.02) to changes in AEE. However, subjects who possessed a high baseline SSCP did not increase SSCP or AEE, whereas subjects with low to moderate baseline SSCP demonstrated a significant increase in both SSCP (low +0.54 and moderate +0.47 m·s-1) and AEE (low +158 and moderate +333 kcal·d-1) post-training (all p less than 0.05). Our findings suggest that among subjects with low to moderate baseline SSCP, 16 weeks of combined aerobic and resistance training can increase SSCP and free-living AEE. However, subjects with high baseline SSCP may require tailored exercise to increase SSCP and possibly AEE.

Over the last decade, there has been a growing interest in the utility of nitrate (NO3(−)) supplementation to improve exercise-related performance. After consumption, dietary NO3(−) can be reduced to nitric oxide, a free radical gas involved in numerous physiological actions including blood vessel vasodilation, mitochondrial respiration, and skeletal muscle contractile function. Emerging evidence indicates that dietary NO3(−) supplementation has a small but nevertheless significant beneficial effect on endurance performance through the combined effects of enhanced tissue oxygenation and metabolic efficiency in active skeletal muscle. There is further evidence to suggest that dietary NO3(−) exerts a direct influence on contractile mechanisms within the skeletal muscle through alterations in calcium availability and sensitivity. Response heterogeneity and sizeable variability in the nitrate content of beetroot juice products influence the effectiveness of dietary NO3(−) for exercise performance, and so dosing and product quality, as well as training history, sex, and individual-specific characteristics, should be considered.

This study tested the hypotheses that compared to drinking water, consumption of a caffeinated soft drink sweetened with high‐fructose corn syrup (HFCS) attenuates the cutaneous vasodilatory response to local skin heating without (Protocol 1) and following ischemia‐reperfusion injury (Protocol 2). In a randomized, counterbalanced crossover design, 14 healthy adults (25 ± 3 year, 6 women) consumed 500 ml of water (water) or a caffeinated soft drink sweetened with HFCS (Mtn. Dew, DEW). Thirty minutes following beverage consumption local skin heating commenced on the right forearm (Protocol 1), while on the left forearm ischemia‐reperfusion commenced with 20 min of ischemia followed by 20 min of reperfusion and then local skin heating (Protocol 2). Local skin heating involved 40 min of heating to 39℃ followed by 20 min of heating to 44℃. Skin blood flow (SkBf, laser Doppler) data were normalized to mean arterial pressure and are presented as a cutaneous vascular conductance (CVC) and as percentage of the CVC response during heating to 44℃ (%CVCmax). Protocol 1: During local heating at 39℃, no differences were observed in CVC (water: 2.0 ± 0.6 PU/mmHg; DEW: 2.0 ± 0.8 PU/mmHg, p = 0.83) or %CVCmax (water: 59 ± 14%; DEW 60 ± 15%, p = 0.84) between trials. Protocol 2: During local skin heating at 39℃, no differences were observed in CVC (water: 1.7 ± 0.5 PU/mmHg; DEW: 1.5 ± 0.5 PU/mmHg, p = 0.33) or %CVCmax (water: 64 ± 15%; DEW 61 ± 15% p = 0.62) between trials. The cutaneous microvascular vasodilator response to local heating with or without prior ischemia‐reperfusion injury is not affected by acute consumption of a caffeinated soft drink sweetened with HFCS., We examined the effect of consumption of a caffeinated soft drink sweetened with high‐fructose corn syrup on the cutaneous vasodilatory response to local skin heating without and following ischemia‐reperfusion injury. We identified that the cutaneous microvascular vasodilator response to local heating with or without prior ischemia‐reperfusion injury is not affected by acute consumption of a caffeinated soft drink sweetened with high‐fructose corn syrup.

Limited work has evaluated how leg press strength (LPS), relative to body mass (i.e., rLPS), affects heart rate (HR) responses during activities of daily living. Such information would prove useful by informing a specific level of rLPS needed to promote independent mobility and physical activity. Secondary analyses were performed on baseline measures of 76 untrained older (65 ± 4 y) women. After familiarization, one-repetition maximum leg press was converted to rLPS by dividing the external load lifted (kg) by body mass (BM). Participants were stratified according to percentile of age-group norms of rLPS: ≤50 % (low, ≤0.99 kg/BM, n = 15), 51-89 % (middle, 1.0-1.31 kg/BM, n = 31), and ≥90 % (high, ≥1.32 kg/BM, n = 30). HR was measured at rest and during laboratory-based tasks including fixed-speed (0.89 m·s

Recent reports have acknowledged the underrepresentation of women in the field of dietary nitrate (NO3-) research. Undoubtedly, greater participation from women is warranted to clarify potential sex differences in the responses to dietary NO3- interventions. However, careful consideration for the effects of sex hormones - principally 17β-estradiol - on endogenous nitric oxide (NO) synthesis and dietary NO3- reductase capacity is necessary for improved interpretation and reproducibility of such investigations. From available literature, we present a narrative review describing how hormonal variations across the menstrual cycle, as well as with menopause, may impact NO biosynthesis catalyzed by NO synthase enzymes and NO3- reduction via the enterosalivary pathway. In doing so, we address methodological considerations related to the menstrual cycle and hormonal contraceptive use relevant for the inclusion of premenopausal women along with factors to consider when testing postmenopausal women. Adherence to such methodological practices may explicate the utility of dietary NO3- supplementation as a means to improve vascular function among women across the lifespan.

Whether slowing disease progression or combatting the ills of advancing age, the extensive utility of exercise training has contributed to the outright declaration by the American College of Sports Medicine that ‘exercise is medicine’. Consistent with general framework of adaptation, the advantages of exercise training are indiscriminate—benefitting even the most susceptible clinical populations. Still, the benefit of exercise training presupposes healthy adaptation wherein progressive overload matches sufficient recovery. Indeed, a difference exists between healthy adaptation and non-functional over-reaching (ie, when internal/external load exceeds recovery capacity)—a difference that may be blurred by cancer treatment and/or comorbidity. Recent advances in smartwatches make them ideally suited to non-invasively monitor the physiological stresses to exercise training. Resolving whether individuals are successfully adapting to exercise training via load monitoring bears clinical and practical relevance. While behaviour-change research aims to identify positive constructs of exercise adherence, further attention is needed to uncover how to optimise exercise prescription among cancer populations. Herein, we briefly discuss the constituents of exercise load monitoring, present examples of internal and external load and consider how such practices can be applied to cancer populations.

NEW FINDINGS What is the central question of this study? Does the link between cardiorespiratory fitness and gut microbiota diversity persist after adjusting for the potential effects of percentage body fat and activity-related energy expenditure (AEE)? What is the main finding and its importance? This is the first study to examine the link between cardiorespiratory fitness and gut microbiota diversity while accounting for the underlying effects of percentage body fat and free-living AEE. Results from the present work suggest that cardiorespiratory fitness, not physical activity, is a superior correlate of gut microbiota diversity among post-primary treatment, non-metastatic breast cancer survivors. ABSTRACT Cancer treatment uniquely triggers multiple physiological shifts detrimental to overall health. Although previous research indicates a link between the gut microbiota and cardiorespiratory fitness, it is unclear whether these findings are attributable to potential underlying effects of percentage body fat or free-living activity energy expenditure (AEE). The microbe composition of faecal specimens from 37 breast cancer survivors was determined using 16S microbiome analyses. Individual-sample microbiota diversity (α-diversity) and between-sample community differences (β-diversity) were examined. Peak oxygen uptake ( VO2peak ) was estimated from a graded exercise test consistent with the modified Naughton protocol, in which exercise terminates at 85% of age-predicted maximal heart rate. The AEE was measured over 10 days using doubly labelled water, wherein the percentage body fat was calculated from total body water. Pearson correlations revealed α-diversity indices (Chao1, observed species, PD whole tree and Shannon) to be positively associated with VO2peak (r = 0.34-0.51; P

Diet and physical activity share an association with cancer mortality. We investigated whether empirically-defined dietary patterns modified the association between a composite of physical health and cancer mortality. METHODS: We performed analysis among participants from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. Physical health (PH) composite was assessed by the product of baseline heart rate and systolic blood pressure, a reliable measurement of myocardial oxygen demand, and self-reported physical activity. Participant adherence was assessed with empirically-defined dietary patterns including: Convenience (including Chinese and Mexican foods, pasta, pizza), Plant-based (including fruits, vegetables), Southern (including added fats, fried foods, sugar-sweetened beverages), Sweets/Fats (including sugary foods) and Alcohol/Salads (including alcohol, green-leafy vegetables, salad dressing) was examined as an effect modifier. We performed comparisons across PH composite risk groups (i.e., severe, high, moderate, and low risk). We estimated hazard ratios (HRs) and associated 95% confidence intervals (CIs) by PH composite groups, stratified by dietary patterns. RESULTS: Among 20,857 participants, 18% were defined as severe-risk PH, 30% were high-risk, 15% were moderate-risk PH, and 38% were low-risk PH. The most common dietary pattern adhered to by severe-risk PH participants was the southern based diet (30% adhering, p value CONCLUSIONS: Dietary patterns influence cancer mortality risk; however cardiovascular health is independently associated with greater long-term risk of cancer death. Citation Format: Akwasi O. Aduboffour, Stephen J. Carter, George Howard, Saira Khan, Marquita Lewis-Thames, Justin Xavier Moore, PhD, MPH X. Moore. The moderating role of dietary patterns on physical health and risk of cancer mortality in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3653.

We tested the hypothesis that ingestion of a caffeinated soft drink sweetened with high‐fructose corn syrup acutely increases arterial stiffness. In a randomized counterbalanced, crossover design, fourteen healthy adults (25 ± 3 years, 6 women) reported to the laboratory for two experimental visits where 500 ml of tap water (H2O) or 500 ml of Mountain Dew® (a caffeinated soft drink sweetened with high‐fructose corn syrup (HFCS)) were consumed. Arterial stiffness (carotid‐to‐femoral pulse wave velocity (cfPWV)), peripheral and central blood pressures were measured pre‐consumption, 30 min post‐consumption, and 120 min post‐consumption. Prior to each measurement period, beat‐to‐beat hemodynamic measures were collected. Changes in heart rate, blood pressure, and cardiac output from pre‐consumption did not differ between trials at any timepoint (p ≥ 0.06). Moreover, changes in peripheral or central blood pressures from pre‐consumption did not differ between trials (p ≥ 0.84). Likewise, changes in cfPWV from pre‐consumption to 30 min post‐consumption (HFCS: 0.2 ± 0.3 m/s, H2O: 0.0 ± 0.3 m/s, p = 0.34) and 120 min post‐consumption (HFCS: 0.3 ± 0.4 m/s, H2O: 0.2 ± 0.3 m/s, p = 0.77) did not differ. Changes in aortic augmentation pressure, augmentation index, augmentation index corrected to a heart rate of 75 bpm, and reflection magnitude did not differ between conditions at 30 min post‐ (p ≥ 0.55) or 120 min post‐ (p ≥ 0.18) consumption. In healthy young adults, ingesting 500 ml of a commercially available caffeinated soft drink sweetened with high‐fructose corn syrup does not acutely change indices of arterial stiffness and wave reflection., This study investigated whether the ingestion of a caffeinated soft drink sweetened with high‐fructose corn syrup acutely modified arterial stiffness. In a randomized counterbalanced, crossover design, fourteen young healthy adults consumed 500 ml of tap water or a caffeinated soft drink sweetened with high‐fructose corn syrup, after which carotid‐to‐femoral pulse wave velocity was measured. This study found that ingesting 500 ml of a commercially available caffeinated soft drink sweetened with high‐fructose corn syrup does not acutely change indices of arterial stiffness.

Summary Quantile regression is a semiparametric method for modeling associations between variables. It is most helpful when the covariates have complex relationships with the location, scale, and shape of the outcome distribution. Despite the method’s robustness to distributional assumptions and outliers in the outcome, regression quantiles may be biased in the presence of measurement error in the covariates. The impact of function-valued covariates contaminated with heteroscedastic error has not yet been examined previously; although, studies have investigated the case of scalar-valued covariates. We present a two-stage strategy to consistently fit linear quantile regression models with a function-valued covariate that may be measured with error. In the first stage, an instrumental variable is used to estimate the covariance matrix associated with the measurement error. In the second stage, simulation extrapolation (SIMEX) is used to correct for measurement error in the function-valued covariate. Point-wise standard errors are estimated by means of nonparametric bootstrap. We present simulation studies to assess the robustness of the measurement error corrected for functional quantile regression. Our methods are applied to National Health and Examination Survey data to assess the relationship between physical activity and body mass index among adults in the United States.

Background Previous narrative reviews have concluded that dietary nitrate (NO3−) improves maximal neuromuscular power in humans. This conclusion, however, was based on a limited number of studies, and no attempt has been made to quantify the exact magnitude of this beneficial effect. Such information would help ensure adequate statistical power in future studies and could help place the effects of dietary NO3− on various aspects of exercise performance (i.e., endurance vs. strength vs. power) in better context. We therefore undertook a systematic review and individual participant data meta-analysis to quantify the effects of NO3− supplementation on human muscle power. Methods The literature was searched using a strategy developed by a health sciences librarian. Data sources included Medline Ovid, Embase, SPORTDiscus, Scopus, Clinicaltrials.gov, and Google Scholar. Studies were included if they used a randomized, double-blind, placebo-controlled, crossover experimental design to measure the effects of dietary NO3− on maximal power during exercise in the non-fatigued state and the within-subject correlation could be determined from data in the published manuscript or obtained from the authors. Results Nineteen studies of a total of 268 participants (218 men, 50 women) met the criteria for inclusion. The overall effect size (ES; Hedge’s g) calculated using a fixed effects model was 0.42 (95% confidence interval (CI) 0.29, 0.56; p = 6.310 × 10− 11). There was limited heterogeneity between studies (i.e., I2 = 22.79%, H2 = 1.30, p = 0.3460). The ES estimated using a random effects model was therefore similar (i.e., 0.45, 95% CI 0.30, 0.61; p = 1.064 × 10− 9). Sub-group analyses revealed no significant differences due to subject age, sex, or test modality (i.e., small vs. large muscle mass exercise). However, the ES in studies using an acute dose (i.e., 0.54, 95% CI 0.37, 0.71; p = 6.774 × 10− 12) was greater (p = 0.0211) than in studies using a multiple dose regimen (i.e., 0.22, 95% CI 0.01, 0.43; p = 0.003630). Conclusions Acute or chronic dietary NO3− intake significantly increases maximal muscle power in humans. The magnitude of this effect–on average, ~ 5%–is likely to be of considerable practical and clinical importance. Supplementary Information The online version contains supplementary material available at 10.1186/s12970-021-00463-z.

OBJECTIVES: Intermittent calorie restriction has emerged as an effective alternative to continuous calorie restriction to impart favorable health benefits. However, there remains a degree of uncertainty about the optimal fasting length to simultaneously improve metabolic flexibility and promote positive behavior-change. While a 16-hr fast is commonly employed, it is possible that a shorter fast could result in similar metabolic benefits and better longer term adherence. Thus, we compared changes in hormone response between two 4-hr time intervals of fasting – 11–15 hrs. vs. 15–19 hrs. METHODS: Secondary analyses were performed from a 38-hr fasting study that enrolled 24 healthy, European men (18–30 y) with normal body mass index. Participants initiated a fast at 2300, arrived to the laboratory at 0800, and continued fasting in individual rooms. Venous blood was sampled at 13 time-points to measure insulin, glucose, adrenocorticotropin (ACTH), C-peptide, cortisol, and adiponectin via immunoassays. Data were normally distributed without outliers or missing values. Within-group differences were analyzed with paired t-tests. RESULTS: Insulin (pmol/L) declined between 11–15 hrs. (7.00; CI = 0.97, 13.02; P = .025), but not 15–19 hrs. (5.67; CI = –0.65, 11.98; P = .076). The decline in C-peptide (nmol/L) was sharper between 11–15 hrs. (0.09; CI = 0.05, 0.13; P = < .001), compared to 15–19 hrs. (0.06; CI = 0.02, 0.09; P = .003). Cortisol (nmol/L) also steeply declined between 11–15 hrs. (60.09; CI = 30.58, 89.59; P = < .001), but slightly increased between 15–19 hrs. (10.75; CI = −33.15, 11.65; P = 0.331). The change in glucose (mmol/L) was not different between 11–15 hrs. (0.02 mmol/L; CI = −0.15, 0.19; P = 0.784), but sharply decreased between 15–19 hrs. (0.24; CI = 0.10, 0.39; P = 0.002). No differences were detected for ACTH or adiponectin. CONCLUSIONS: Though substrate oxidation was not measured, changes in insulin, C-peptide, cortisol, and glucose were consistent with increased gluconeogenesis during 11–15 hrs. and lipid oxidation during 15–19 hrs. of fasting. Whereas cortisol often declines throughout the day, a slight increase was noted between 15–19 hrs. – evidence of a heightened sympathetic activity. Further study of hormone response during intermittent fasting will inform optimal length to promote health benefits and longer term adherence. FUNDING SOURCES: None

In the United States, latest projections indicate the number of adults 65 years of age and older is expected to double by 2050. Given that increased oxidative stress is a hallmark of aging, it is understandable that waning nitric oxide and chronic degenerative disease arise in tandem. To this end, translational evidence-based strategies are needed to mitigate the impending toll on personal and public health. Dietary nitrate supplementation, particularly in the form of beetroot juice, is an active area of inquiry that has gained considerable attention in recent years. Compelling evidence has revealed beetroot juice can elicit potent physiological responses that may offer associated health benefits for multiple clinical disorders including hypertension, dementia, and sarcopenia. Even in the absence of overt disease, age-related impairments in cardiovascular and skeletal muscle function may uniquely benefit from beetroot juice supplementation as evidence has shown blood pressure lowering effects and improved muscle function/contractility – presumably from increased nitric oxide bioavailability. This, in turn, presents a practical opportunity for susceptible populations to support ease of movement and exercise tolerance, both of which may promote free-living physical activity. A theoretical rationale details the potential health effects of dietary nitrate supplementation, wherein a working framework hypothesizes beetroot juice consumption prior to structured exercise training may offer synergistic benefits to aid healthy aging and independent-living among older adults.

It is unclear how resting myocardial workload, as indexed by baseline measures of rate-pressure product (RPP) and physical activity (PA), is associated with the overall risk of cancer mortality. We performed prospective analyses among 28,810 men and women from the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. We used a novel physical health (PH) composite index and categorized participants into one of four groups based on combinations from self-reported PA and RPP: 1) No PA and High RPP; 2) No PA and Low RPP; 3) Yes PA and High RPP; and 4) Yes PA and Low RPP. We examined the association between baseline PH composite and cancer mortality adjusted for potential confounders using Cox regression. A total of 1191 cancer deaths were observed over the 10-year observation period, with the majority being lung (26.87%) and gastrointestinal (21.49%) cancers. Even after controlling for sociodemographics, health behaviors, baseline comorbidity score, and medications, participants with No PA and High RPP had 71% greater risk of cancer mortality when compared to participants with PA and Low RPP (adjusted HR: 1.71, 95% CI: 1.42–2.06). These associations persisted after examining BMI, smoking, income, and gender as effect modifiers and all-cause mortality as a competing risk. Poorer physical health composite, including the novel RPP metric, was associated with a nearly 2-fold long-term risk of cancer mortality. The physical health composite has important public health implications as it provides a measure of risk beyond traditional measure of obesity and physical activity.

OBJECTIVE It is unclear whether there are race-specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training. METHODS Overweight, sedentary African American (AA; n = 72) and European American (EA; n = 68) women were provided an 800-kcal/d diet to reduce BMI < 25 kg/m2 . Regional fat-free mass was measured with dual-energy x-ray absorptiometry. Steady-state VO2 and heart rate responses during walking were measured. RESULTS AA women had greater RSMI and preserved RSMI during diet alone, while RSMI was significantly reduced among EA women (EA women -3.6% vs. AA women + 1.1%; P < 0.05). Diet + resistance training subjects retained RSMI (EA women + 0.2% vs. AA women + 1.4%; P = 50.05), whereas diet + aerobic training subjects decreased RSMI (EA women -1.4% vs. AA women -1.5%; P < 0.05). Maintenance of RSMI was related to delta walking ease and economy. CONCLUSIONS Compared with AA women, EA women are less muscular and lose more muscle during weight loss without resistance training. During diet-induced weight loss, resistance training preserves skeletal muscle, especially among premenopausal EA women. Maintenance of muscle during weight loss associates with better ease and economy of walking.

Age-related declines in health and function make locomotion increasingly difficult leading to reductions in non-exercise activity thermogenesis (NEAT), skeletal muscle size and strength, and increased adiposity. Exercise is an important strategy to attenuate loss of function through the life cycle. Despite claims to the contrary, high-intensity exercise is important for the prevention of obesity and sarcopenia with advancing age. Therefore, the purpose of this mini-review is to present literature supporting the contention that low volume, high-intensity aerobic and/or resistance training can slow sarcopenia, sustain ease of movement, stimulate NEAT, and attenuate the accretion of fat mass.

We hypothesized exercise training-induced improvements in ease of walking would associate with favorable changes in objectively measured physical activity (PA) and self-reported depressive symptoms following a PA behavior-change intervention in non-metastatic breast cancer survivors (BCS). Twenty-seven BCS received random assignment to an intervention (INT) or control group (CON). INT included counseling/group discussions coupled with supervised exercise tapered to unsupervised exercise. PA, depressive symptoms, and ease of walking were evaluated pre-/post-intervention using 10-day accelerometry, HADS depression subscale, and indirect calorimetry during a standardized treadmill test, respectively. PA composite score was calculated by converting weekly minutes of moderate-to-vigorous PA and average steps/day to z-scores then dividing the sum by 2. Cardiac efficiency was determined by dividing steady-state oxygen uptake by heart rate to evaluate the volume of oxygen consumed per heartbeat. ANCOVA revealed a significant time by group interaction showing the INT group exhibited greater positive changes in the PA composite compared to the CON (INT, + 0.14 ± 0.66 au vs. CON, − 0.48 ± 0.49 au; p = 0.019; η p 2 = 0.21). Changes occurring from baseline to follow-up, among all participants, revealed improved ease of walking (less oxygen uptake) associated with increased PA composite (r = − 0.52; p = 0.010) and lower depressive symptomology (r = 0.50; p = 0.012) adjusted for age, race, and months since cancer diagnosis. Increased cardiac efficiency during the standardized treadmill test also associated with less daily sedentary time (r = − 0.52; p = 0.021). These data support the assertion that reducing the physiological difficulty of walking may contribute to greater engagement in free-living PA, less sedentary time, and decreased psychosocial distress among BCS.

IntroductionResting energy expenditure (REE) increases after an intense exercise; however, little is known concerning mechanisms.PurposeThe purpose of this study was to determine effects of a single bout of moderate-intensity continuous (MIC) aerobic exercise, or high-intensity interval (HII

African American (AA) and European American (EA) women often exhibit differences in hemoglobin (Hb) and 25-hydroxyvitamin D [25(OH)D], both of which can be altered by calorie restriction leading to weight loss. Given these known differences, it is of clinical interest to examine the potential for race-specific, adverse responses to weight loss. Sixty-four overweight (BMI 27–29.9 kg/m2), premenopausal women consumed a standardized, very-low calorie diet to reduce BMI < 25 kg/m2. Ancestry informative markers provided estimates of African admixture, an objective mean of expressing race. Blood sampling and anthropometric measures were performed at baseline and upon meeting target BMI. At baseline, in the overweight state, Hb (g/dL) (AA, 11.7 ± 0.9 vs. EA, 12.5 ± 0.8; p < .01) and 25(OH)D (nmol/L) (AA, 35.7 ± 12.9 vs. EA, 57.0 ± 20.0; p < .01) were lower in AAs. After weight loss, Hb decreased (AA, -0.5 ± 0.7 vs. EA, -0.4 ± 0.6; p = .48) to a similar extent among races. Conversely, 25(OH)D increased (AA, 43.4 ± 14.0 vs. EA 68.2 ± 24.3; p < .01) though the magnitude of change (Δ) was not different (AA, +7.8 ± 13.5 vs. EA, +11.2 ± 16.7; p = .37) between races. Multiple linear regression revealed a positive association between ΔHb and Δ25(OH)D (r = .386; p < .01) adjusted for African admixture, Δtestosterone, and Δbody fat%. Path analyses revealed a significant indirect effect of Δbody fat% on ΔHb through Δ25(OH)D, β =-0.023, CI [-0.06, -0.004]. Following 15% weight loss, participants with the largest increase in serum 25(OH)D exhibited the smallest decrease in Hb. Future research should clarify the optimal degree of calorie restriction to stimulate weight loss while mitigating the potential risk of anemia associated with dieting efforts.

In this proof-of-concept pilot study, our purpose was to determine correlations between gut microbiota composition and alterations in cardiorespiratory fitness and psychosocial outcomes among post-primary treatment breast cancer survivors (BCS). Composition of the gut microbiota in BCS (n = 12) was assessed at baseline (M0) and at the end of 3 months (M3) using Illumina MiSeq DNA Sequencing of the 16S rRNA gene. Gut microbiota composition was analyzed using the QIIME bioinformatics software and represented through diversity metrics and taxa analyses. Cardiorespiratory fitness, fatigue, anxiety, depression, and sleep dysfunction were assessed at M0 and M3 via the submaximal treadmill test, Fatigue Symptom Inventory, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index, respectively. Increased fatigue interference in BCS was associated with increased mean within-sample Shannon diversity (organism richness and evenness) (p = 0.009). Weighted UniFrac analysis (shifts in taxa relative abundance) revealed significant differences in between-sample (beta) diversity for changes in fatigue interference (p = 0.01) and anxiety (p = 0.022), with a trend observed for fatigue intensity and sleep dysfunction (p

As the biomedical community races to disentangle the unknowns associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the virus responsible for causing coronavirus disease (COVID-19) – the link between diminished immune function and individuals with obesity raises important questions about the possibility for greater viral pathogenicity in this population. Increased adiposity may undermine the pulmonary microenvironment wherein viral pathogenesis and immune cell trafficking could contribute to a maladaptive cycle of local inflammation and secondary injury. A further challenge to those with obesity during the current pandemic may involve vitamin D deficiency/insufficiency. In the interest of personal and public health, we caution decision/policy makers alike not to pin all hope on a proverbial ‘silver bullet.’ Until further breakthroughs emerge, we should remember that modifiable lifestyle factors like diet and physical activity should not be marginalized. Decades of empirical evidence supports both as key factors promoting health and wellness.

Hunter, GR, Neumeier, WH, Chandler-Laney, PC, Carter, SJ, Borges, JH, Hornbuckle, LM, Plaisance, EP, and Fisher, G. Ratings of perceived exertion during walking predicts endurance independent of physiological effort in older women. J Strength Cond Res 34(5): 1340-1344, 2020-This study aimed to determine whether ratings of perceived exertion (RPE) and physiological effort at different exercise intensities relate to exercise endurance. Ninety-eight sedentary women (older than 60 years) completed 3 submaximal locomotion tasks: (a) stair climbing, (b) flat walking at 2 mph, and (c) grade walking at 2 mph. Maximal treadmill endurance was measured at least 3 days before the submaximal tests. Oxygen uptake was measured during all tests, and RPE were collected for the submaximal tasks. Ratings of perceived exertion during moderate-intensity exercise (walking on the flat at 43% V[Combining Dot Above]O2max, partial R = -0.35, p0.01), but not higher intensity exercise (grade walk at 59% V[Combining Dot Above]O2max, p = 0.49, and stair climbing at 67% V[Combining Dot Above]O2max, p = 0.17), were related to endurance even after adjusting for aerobic capacity and physiological effort (composite of maximal heart rate, ventilation, and respiratory exchange ratio). However, physiological effort was significantly related to endurance for the higher intensity exercise (both grade walk and stair climbing partial R-0.24, p0.02). Similar to previous findings that subjective ratings of fatigue at rest were related to RPE during low/moderate-intensity exercise, but not higher intensity exercise, these data further support Ekkekakis's dual-mode hypothesis that cognitive factors influence RPE during low/moderate-intensity exercise. A practical application is that the coach and personal trainer should know that physiological effort seems to play a greater role in influencing endurance than RPE as intensity of exercise increases.

PURPOSE: With accelerometry, the utility to detect changes in physical activity are predicated on the assumption that walking energetics and gait mechanics do not change. The present work examined associations between changes (Δ) in walking energetics, exercise self-efficacy, and several accelerometer-derived metrics. METHODS: Secondary analyses were performed among a sub-sample (n=29) of breast cancer survivors participating in a larger randomized trial. During 4 minutes of treadmill walking (0.89 m·s(−1), 0% grade), indirect calorimetry quantified steady-state energy expenditure (EE), wherein, participants were fitted with a heart rate monitor and hip-worn triaxial accelerometer. Exercise self-efficacy was measured using a 9-item questionnaire, while vector magnitude (VM) and individual planes (e.g., mediolateral, vertical, and anteroposterior) of movement were extracted for data analyses. Evaluations were made at baseline and after 3 months. RESULTS: From baseline to 3 months, the energetic cost of walking (kcals·min(−1)) significantly decreased by an average of −5.1% (p = 0.001; d = 0.46). Conversely, VM significantly increased (p = 0.007; d = 0.53), exclusively due to greater vertical accelerations (acc) (+5.7 ± 7.8 acc; p = 0.001; d = 0.69). Changes in vertical accelerations were inversely and positively associated with Δwalking EE (r = −0.37; p = 0.047) and Δexercise self-efficacy (r = 0.39; p = 0.034), respectively. CONCLUSION: Hip-worn accelerometers do not appear well-suited to correctly detect changes in ease of walking as evidenced by reduced energetic cost. Further research should determine if a divergence between measured EE and vertical accelerations could contribute to erroneous inferences in free-living physical activity.

Cardiovascular (CV) drift, the progressive increase in heart rate (HR) and decrease in stroke volume (SV) during constant rate, moderate intensity exercise, is related to reduced maximal oxygen uptake (V̇O(2max)) during heat stress. Once it has already occurred, it is unknown whether the detrimental effects of CV drift on V̇O(2max) can be reversed. This study tested the hypothesis that fan cooling after CV drift has occurred attenuates decrements in V̇O(2max) associated with CV drift. Eight men completed a control graded exercise test (GXT) in 22°C to measure V̇O(2max). Then on separate, counterbalanced occasions, they completed one 15-min (15MIN) and two 45-min bouts (45NF and 45FAN) of cycling in 35°C, 40% RH at 60% V̇O(2max), each immediately followed by a GXT to measure V̇O(2max). For one of the 45-min trials (45FAN), fan airflow (4.5 m/s) was directed at participants beginning ~5 min before the GXT and continuing throughout the remainder of exercise. The purpose of the separate 15- and 45-min trials was to measure V̇O(2max) during the same time interval that CV drift occurred. HR increased (13.8% and 11.4%) and SV decreased (14.4% and 14.1%) for 45NF and 45FAN, respectively; trials were not different (all P > 0.05). Despite a decrease in mean skin temperature of ~1°C with fan use, V̇O(2max) decreased similarly between conditions (17% vs. 15% for 45NF and 45FAN, P = 0.54). Fan cooling after CV drift was insufficient to reverse the negative consequences of CV drift on V̇O(2max) after prolonged exercise in a hot environment. Abbreviations: 15MIN: 15-min trial; 45FAN: 45-min, fan trial; 45NF: 45-min, no fan trial; ANOVA: Analysis of variance; CV: Cardiovascular; GXT: Graded exercise test; HR: Heart rate; SV: Stroke volume; T̅(b): Mean body temperature; T(re): Rectal temperature; T̅(sk): Mean skin temperature; V̇O(2max): Maximal oxygen uptake

IntroductionAntimicrobial resistance (AMR) is a major global health challenge. Pharmacists play a key role in the health care setting to support the quality use of medicines. The education and training of pharmacy students have the potential to impact on patterns of antibiotic use in community and hospital settings. The aim of this study was to investigate and compare antibiotic use and knowledge of antibiotics and AMR among undergraduate pharmacy students in Australian and Sri Lankan universities.MethodsA cross-sectional survey was conducted in Australian and Sri Lankan universities that offer a pharmacy degree. A paper-based survey was utilised in Sri Lanka and an identical survey distributed online among pharmacy students in Australia. Descriptive and comparative data analyses were performed.Results476 pharmacy students from 14 universities in Australia and 466 students from 6 universities in SL completed the survey. Participants commonly reported previous antibiotic use [Australia (88%) and Sri Lanka (86%)]. The majority of students [Australia (89%) and Sri Lanka (77%)] reported they obtained antibiotics with a prescription. Australian pharmacy students correctly reported regarding optimal antibiotic use for certain disease conditions when compared to Sri Lankan students (PConclusionThis study provides an understanding about antibiotic consumption and knowledge on AMR among pharmacy students in a developed country, Australia and a developing country, Sri Lanka. These findings identify possible misconceptions about antibiotics and a lower level of knowledge of AMR amongst Sri Lankan undergraduate pharmacy students. Future research should focus on implementation of a strategic education plan for undergraduate pharmacy students in Sri Lankan universities. The curricula of pharmacy courses in Australian universities may inform such a plan.

Sarcopenia not only affects the ability to lead an active lifestyle but also contributes to increased obesity, reduced quality of life, osteoporosis, and metabolic health, in part due to reduced locomotion economy and ease. On the other hand, increased obesity, decreased quality of life, and reduced metabolic health also contribute to sarcopenia. The purpose of this mini-review is to discuss the implications sarcopenia has for the development of obesity and comorbidities that occur with aging.

Background Postmenopausal women exhibit higher rates of disability and cardiovascular disease (CVD) with aging compared to men. Whereas habitual exercise training is a known strategy to enhance physiologic function in men and premenopausal women, exercise-related adaptations are often modest in postmenopausal women. We propose dietary nitrate (beetroot juice) administered prior to exercise training may be a feasible approach to improve mobility and cardio-metabolic health outcomes in postmenopausal women. Methods Our randomized, placebo-controlled study aims to determine preliminary effects sizes for changes in functional mobility and endothelium-dependent vasodilation across three study arms: exercise only (EX), exercise + placebo (EX + PL), and exercise + beetroot (EX + BR). Thirty-six postmenopausal women are recruited in small cohorts wherein group exercise is implemented to facilitate social support and adherence to an 8-week training progression. Participants are randomized to one of three study arms (n = 12 per group) following baseline assessments. Post-intervention assessments are used to determine pre-post changes in outcome measures including distance covered during a 6 min walk test, walking economy, muscle speed and power, and endothelial-dependent vasodilation as determined by flow-mediated dilation. Measures of feasibility include recruitment, retention, adherence to exercise prescription, perceived exercise session difficulty, and adverse event rates. Discussion Evidence-based, translational strategies are needed to optimize exercise training-related adaptations in postmenopausal women. Findings will inform larger randomized clinical trials to determine if pre-exercise consumption of beetroot juice is an efficacious strategy to promote mobility and attenuate CVD disease risk.

Research showing a link between exercise-induced changes in aerobic fitness and reduced fatigue after a cancer diagnosis has been inconsistent. We evaluated associations of fatigue and rate-pressure product (RPP), a reliable index of myocardial oxygen demand, at rest and during submaximal walking following a physical activity intervention among post-primary treatment breast cancer survivors (BCS).Secondary analyses of 152 BCS in a randomized controlled trial testing a physical activity intervention (INT) versus usual care (UC) were performed. The INT group completed counseling/group discussions along with supervised exercise sessions tapered to unsupervised exercise. Evaluations were made at baseline and immediately post-intervention (M3) on measures of physical activity (accelerometry), graded walk test, and average fatigue over the previous 7 days. RPP was calculated by dividing the product of heart rate and systolic blood pressure by 100.Resting and submaximal RPPs were significantly improved in both groups at M3; however, the magnitude of change (∆) was greater in the INT group from stage 1 (∆RPP1; INT -13 ± 17 vs. UC -7 ± 18; p = 0.03) through stage 4 (∆RPP4; INT -21 ± 26 vs. UC -9 ± 24; p 0.01) of the walk test. The INT group reported significantly reduced fatigue (INT -0.7 ± 2.0 vs. UC +0.1 ± 2.0; p = 0.02) which was positively associated with ∆RPP during stages 2-4 of the walk test but not ∆aerobic fitness.Lower RPP during submaximal walking was significantly associated with reduced fatigue in BCS.Exercise/physical activity training programs that lower the physiological strain during submaximal walking may produce the largest improvements in reported fatigue.