Greater Cardiorespiratory Fitness Research Articles

Sleep Quality Moderates the Associations between Cardiorespiratory Fitness and Hippocampal and Entorhinal Volume in Middle-Aged and Older Adults.

As individuals age, the entorhinal cortex (ERC) and hippocampus-crucial structures for memory-tend to atrophy, with related cognitive decline. Simultaneously, lifestyle factors that can be modified, such as exercise and sleep, have been separately linked to slowing of brain atrophy and functional decline. Yet, the synergistic impact of fitness and sleep on susceptible brain structures in aging adults remains uncertain. We examined both independent and interactive associations of fitness and subjective sleep quality with regard to ERC thickness and hippocampal volume in 598 middle-aged and older adults from the Human Connectome Lifespan Aging Project. Cardiorespiratory fitness was assessed using the 2-minute walk test (2MWT), while subjective sleep quality was measured with the continuous Pittsburgh Sleep Quality Index (PSQI) global score. High-resolution structural magnetic resonance imaging was used to examine mean ERC thickness and bilateral hippocampal volume. Through multiple linear regression analyses, we investigated the moderating effects of subjective sleep quality on the association between fitness and brain structure, accounting for age, sex, education, body mass index, gait speed, and subjective physical activity. We found that greater cardiorespiratory fitness, but not subjective sleep quality, was positively associated with bilateral hippocampal volume and ERC thickness. Notably, significant interaction effects suggest poor subjective sleep quality was associated with a weaker association between fitness and both hippocampal volume and ERC thickness. Findings suggest the potential importance of both cardiorespiratory fitness and subjective sleep quality in preserving critical, age-vulnerable brain structures. Interventions targeting brain health should consider potential combined effects of sleep and fitness on brain health.

Life's Essential 8 Cardiovascular Health Score and Cardiorespiratory Fitness in the Community.

The relation of cardiorespiratory fitness (CRF) to lifestyle behaviors and factors linked with cardiovascular health remains unclear. We aimed to understand how the American Heart Association's Life's Essential 8 (LE8) score (and its changes over time) relate to CRF and complementary exercise measures in community-dwelling adults. Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise testing for direct quantification of peak oxygen uptake (V̇O2). A 100-point LE8 score was constructed as the average across 8 factors: diet, physical activity, nicotine exposure, sleep, body mass index, lipids, blood glucose, and blood pressure. We related total LE8 score, score components, and change in LE8 score over 8 years with peak V̇O2 (log-transformed) and complementary CRF measures. In age- and sex-adjusted linear models (N=1838, age 54±9 years, 54% women, LE8 score 76±12), a higher LE8 score was associated favorably with peak V̇O2, ventilatory efficiency, resting heart rate, and blood pressure response to exercise (all P<0.0001). A clinically meaningful 5-point higher LE8 score was associated with a 6.0% greater peak V̇O2 (≈1.4 mL/kg per minute at sample mean). All LE8 components were significantly associated with peak V̇O2 in models adjusted for age and sex, but blood lipids, diet, and sleep health were no longer statistically significant after adjustment for all LE8 components. Over an ≈8-year interval, a 5-unit increase in LE8 score was associated with a 3.7% higher peak V̇O2 (P<0.0001). Higher LE8 score and improvement in LE8 over time was associated with greater CRF, highlighting the importance of the LE8 factors in maintaining CRF.

Abstract P216: Physical Fitness and Incidence of Metabolic Syndrome Before Midlife in Military Young Adults: A Cohort Study

Background: Cardiorespiratory fitness (CRF) could reduce the risk of metabolic syndrome (MetS), while the association of muscular endurance capacity (MEC) with incident MetS before midlife was rarely investigated. Methods: A total of 2,890 military men and women, aged 18-39 years, free of baseline MetS were followed for new-onset MetS from baseline (2014) through the end of 2020 in Taiwan. All subjects received annual health examinations for an assessment of MetS. Physical fitness was evaluated by CRF (estimated VO 2 max (mL/kg/min), from a 3000-m run) and MEC (2-min push-up numbers), respectively. MetS was defined based on the International Diabetes Federation criteria. The CRF and MEC were divided by tertiles, respectively against the subjects free of MetS for the Kaplan-Meiner survival analysis. Multivariable Cox regression model with adjustments for baseline demographics, body mass index, and physical activity was used to determine the associations of CRF and MEC (continuous variables) with incident MetS. Subgroup analyses within major MetS components were performed. Results: During a median follow-up of 5.8 years, there were 673 (23.3%) incident MetS. The Kaplan-Meiner Curves are shown in Figure 1. Greater CRF and MEC were associated with a lower risk of MetS [HRs and 95% CI: 0.956 (0.926-0.988) and 0.992 (0.985-0.999), respectively]. In the subgroup analyses, there were no heterogeneities within groups, e.g., body mass index, except that the associations for incident MetS were significantly lower in subjects with serum triglycerides &lt;150 mg/dL [HRs: 0.943 (0.900-0.987) and 0.989 (0.981-0.997), respectively] than those with hypertriglyceridemia (both p for interaction =0.01). Conclusion: Both CRF and MEC were inversely associated with incident MetS in military young adults, which was obviously observed in those without hypertriglyceridemia. This cohort study suggests that obtaining greater physical fitness and lower serum triglycerides are important preventive measures to reduce the risk of MetS before midlife.

Cardiorespiratory fitness is associated with cortical thickness of medial temporal brain areas associated with spatial cognition in young but not older adults.

Cardiorespiratory fitness has a potent effect on neurocognitive health, especially regarding the hippocampal memory system. However, less is known about the impact of cardiorespiratory fitness on medial temporal lobe extrahippocampal neocortical regions. Specifically, it is unclear how cardiorespiratory fitness modulates these brain regions in young adulthood and if these regions are differentially related to cardiorespiratory fitness in young versus older adults. The primary goal of this study was to investigate if cardiorespiratory fitness predicted medial temporal lobe cortical thickness which, with the hippocampus, are critical for spatial learning and memory. Additionally, given the established role of these cortices in spatial navigation, we sought to determine if cardiorespiratory fitness and medial temporal lobe cortical thickness would predict greater subjective sense of direction in both young and older adults. Cross-sectional data from 56 young adults (20-35 years) and 44 older adults (55-85 years) were included. FreeSurfer 6.0 was used to automatically segment participants' 3T T1-weighted images. Using hierarchical multiple regression analyses, we confirmed significant associations between greater cardiorespiratory fitness and greater left entorhinal, left parahippocampal, and left perirhinal cortical thickness in young, but not older, adults. Left parahippocampal cortical thickness interacted with age group to differentially predict subjective sense of direction in young and older adults. Young adults displayed a positive, and older adults a negative, correlation between left parahippocampal cortical thickness and sense of direction. Our findings extend previous work on the association between cardiorespiratory fitness and hippocampal subfield structure in young adults to left medial temporal lobe neocortical regions.

Abstract 16232: Life’s Essential 8 Cardiovascular Health Score and Cardiorespiratory Fitness in the Community

Background: Cardiorespiratory fitness (CRF) is a key indicator of cardiovascular health (CVH) and is inversely associated with cardiovascular disease (CVD) and mortality, but its relations with lifestyle behaviors and factors linked with CVH are incompletely elucidated. Hypothesis: Greater CVH, as assessed by a score comprising lifestyle and standard risk factors, is associated with greater CRF. Aim: To evaluate the cross-sectional relations of AHA’s Life’s Essential 8 (LE8) metrics with CRF in the community. Methods: Maximal cardiopulmonary exercise tests (CPET) were performed in the Framingham Heart Study (FHS). An LE8 score was constructed for each participant by averaging scores across all LE8 components (ranging 0-100). We related CRF and other CPET measures with total LE8 score, individual LE8 components as three-level variables (optimal/suboptimal/poor), and changes in LE8 score over an ≈8 year interval. Results: In 1838 FHS participants (age 54±9 years, 54% women, BMI 28±5 kg/m 2 ), mean LE8 score was 76±12. In age- and sex-adjusted models, a higher LE8 score was associated with higher peak VO 2 , better ventilatory efficiency, lower resting heart rate, and favorable blood pressure response to exercise (p&lt;0.0001 for all). A clinically meaningful 5-point higher LE8 score was associated with a 6.0% greater peak VO 2 (≈1.4 ml/kg/min at the sample mean). There was no evidence of effect modification by age, sex, or CVD status. The eight LE8 score components were statistically significantly associated with peak VO 2 in models adjusted for age and sex, but blood lipids, diet, and sleep health were no longer statistically significant after adjustment for all other LE8 components ( Figure ). Over an ≈8-year interval, a 5-unit increase in LE8 score was associated with a 3.7% higher peak VO 2 (p&lt;0.0001). Conclusion: Higher LE8 score is associated with greater CRF in the community, highlighting the importance of CVH as assessed by LE8 metrics in maintaining and promoting CRF.

Influence of Cardiorespiratory Fitness on Cardiac Autonomic Recovery Among Active-Duty Firefighters.

Abstract Cornell, DJ, Flees, RJ, Shemelya, CM, and Ebersole, KT. Influence of cardiorespiratory fitness on cardiac autonomic recovery among active-duty firefighters. J Strength Cond Res XX(X): 000–000, 2023—It has been suggested that an inability of the autonomic nervous system (ANS) to recover after strenuous events is a potential cause of sudden cardiac death among firefighters. The purpose of this study was to examine the influence of cardiorespiratory fitness (CRF) on the heart rate recovery (HRR) kinetics of firefighters. Thirty-seven male career active-duty firefighters completed both a submaximal step test and a maximal treadmill graded exercise test. A monoexponential curve was fit to postexercise submaximal and maximal HRR data of each subject. Subjects were placed into Low CRF (n = 13) and High CRF (n = 24) groups based on the standard peak aerobic capacity (V̇O2peak) criterion of &lt;42 ml·kg−1·minute−1 and ≥42 ml·kg−1·minute−1, respectively. After controlling for age and body mass index, CRF was significantly (p &lt; 0.05) correlated with the decay rate ( ) and asymptote ( ) after submaximal exercise (r sp = −0.556; r sp = −0.637, respectively), as well as the , , and amplitude ( ) after maximal exercise (r sp = −0.353; r sp = −0.416; r sp = 0.603, respectively). High CRF firefighters demonstrated a significantly faster after both submaximal (p = 0.003) and maximal exercise (p = 0.043), a lower after submaximal exercise (p = 0.002), and a higher after maximal exercise (p = 0.001), than Low CRF firefighters. Greater CRF was associated with enhanced HRR kinetics after submaximal and maximal exertion, suggesting that CRF may positively influence the ANS recovery of firefighters.

FRI112 HS135, A Novel Activin And GDF Trap With Dual Cardiopulmonary And Metabolic Mode Of Action, Is Efficacious In An Obesogenic Model Of Heart Failure

Abstract Disclosure: G. Schang: Employee; Self; 35Pharma Inc. M. Poujol de Molliens: Employee; Self; 35Pharma Inc. E. Brûlé: Employee; Self; 35Pharma Inc. C. Chauvet: Employee; Self; 35Pharma Inc. J. Denis: Employee; Self; 35Pharma Inc. A. Sours: Employee; Self; 35Pharma Inc. V. Ganesh: Employee; Self; 35Pharma Inc. G. Tremblay: Employee; Self; 35Pharma Inc. J. Schoelermann: Employee; Self; 35Pharma Inc. M. O'Connor-McCourt: Employee; Self; 35Pharma Inc. Introduction: Heart failure with preserved ejection fraction (HFpEF) remains one of the largest unmet medical needs in cardiovascular medicine. Eighty percent of HFpEF patients are obese, and adiposity is associated with increased HF-related hospitalization. Lean mass, conversely, is a major driver of cardiorespiratory fitness (CRF) in HFpEF, with greater CRF being a predictor of more favourable survival. Therefore, improvement of body composition in addition to cardiac parameters is a desirable treatment goal for novel HFpEF agents. Activins and growth differentiation factors (GDFs) have been validated preclinical and clinically as targets driving the pathophysiology of cardiopulmonary diseases as well as controlling body composition and metabolism. While previous activin targeting agents have shown therapeutic promise in clinical trials, full pathway inhibition remains unachieved. HS135 is an activin receptor ectodomain-based (ActRII) Fc-fusion protein, rationally designed to achieve best-in-class potency against activins and GDFs, without dose-limiting effects that would impede achieving full activity. We have previously demonstrated that HS135 achieves best-in-class in vivo target engagement and induces positive effects on lean body mass and muscle metabolism. Here we sought to assess the combined effect of HS135 on cardiac efficacy and body composition in an obesogenic model of HFpEF. HS135 was also explored in combination with empagliflozin, a recently approved SGLT2 inhibitor in HFpEF which, though effective at reducing HF-related hospitalization, has minimal effect on body composition in patients. Methods: The ability of HS135 to improve heart function was assessed using a validated HFpEF rodent model. Mice were fed a high-fat diet in conjunction with water containing L-NAME for a period of 5 weeks. The mice were then treated with HS135 (5 or 25 mg/kg, twice weekly), empagliflozin (10 mg/kg daily), or a combination of both over 3 weeks. The efficacy of HS135 and empagliflozin was assessed at the end of study by echocardiography, hemodynamics, histological assessments, and biomarker readouts. Results: Animals treated with HS135, empagliflozin, or both, displayed improvements in HF-related readouts. Specifically, test agents significantly decreased heart hypertrophy and lung congestion, and improved cardiac diastolic function and exercise tolerance. Notably, HS135 alone and in combination with empagliflozin significantly increased lean body mass while decreasing fat mass. Conclusion: Potent and selective inhibition of activins and GDFs represents a novel treatment strategy in HFpEF targeting both cardiac effects as well as improvement in body composition in this largely obese patient population. Collectively, these data support the development of HS135 as a novel agent in cardiometabolic and cardiopulmonary diseases, including heart failure. Presentation: Friday, June 16, 2023

Neuro-Cardiovascular Responses to Sympathetic Stimulation in Fighter Pilots.

INTRODUCTION: The chronic effects of regular exposure to high acceleration levels (G-force) on the neuro-cardiovascular system are unclear. We compared the mean arterial pressure (MAP) and cardiac autonomic modulation between nonpilots (NP) vs. military fighter (FP) and transport (TP) pilots. Additionally, we correlated the cardiac autonomic indices with the cardiorespiratory fitness and flight experience of FP.METHODS: A total of 21 FP, 8 TP, and 20 NP performed a tilt test (TT), during which beat-to-beat blood pressure and heart rate were recorded.RESULTS: No difference was detected between groups for changes in MAP and heart rate variability indices during the TT. However, the analysis of areas under the curves showed a greater increase in MAP in FP vs. TP and NP. Conversely, there was a greater decrease in indices reflecting vagal modulation in TP vs. FP and NP (rMSSD, pNN50, and SDNN), and a greater increase in heart rate and sympathovagal balance in TP vs. other groups (LF/HF). The maximal oxygen uptake was strongly correlated with the vagal reserve in FP (r = -0.74). Moreover, the total flying hours of FP were positively correlated with resting HFnu (r = 0.47) and inversely correlated with resting LFnu (r = -0.55) and LF/HF (r = -0.46).CONCLUSION: FP had a higher pressor response to TT than TP and NP. Vagal withdrawal and sympathovagal increase induced by TT in FP were similar vs. NP and attenuated vs. TP. Greater cardiorespiratory fitness and accumulated flying hours in FP seemed to favor lower sympathetic and greater vagal modulation at rest.dos Santos Rangel MV, de Sá GB, Farinatti P, Borges JP. Neuro-cardiovascular responses to sympathetic stimulation in fighter pilots. Aerosp Med Hum Perform. 2023; 94(10):761-769.

Train Smart Study: protocol for a randomised trial investigating the role of exercise training dose on markers of brain health in sedentary middle-aged adults

IntroductionRegular aerobic exercise is associated with improved cognitive function, implicating it as a strategy to reduce dementia risk. This is reinforced by the association between greater cardiorespiratory fitness and larger...

Leisure-time physical activity is more strongly associated with cardiometabolic risk than occupational physical activity: Results from a workplace lifestyle modification program

BackgroundRegular physical activity (PA) plays a key role in the management and prevention of numerous chronic diseases. However, recent studies have suggested that occupational physical activity (OPA) may not always have health benefits. The aim of the present study was to examine the respective contributions of OPA vs. leisure-time physical activity (LTPA) to the variation in the cardiometabolic profile, including cardiorespiratory fitness (CRF), of employees involved in a workplace lifestyle modification program. Our study hypothesis was that LTPA would show a stronger association with indices of cardiometabolic health than OPA. MethodsA mobile health assessment unit was used to assess 5145 workers (3397 men and 1748 women) on site at their workplace. Assessments included lifestyle questionnaires (overall diet quality, type of OPA and level of LTPA), blood pressure measurements, blood tests, anthropometric measurements, and a submaximal treadmill exercise test to assess CRF. Results were adjusted for education, household income and age. ResultsWhen workers were classified on the basis of their OPA (sedentary work, standing work, physical work, and heavy manual work), only a few significant differences in the cardiometabolic profile were observed in men, with those in the physical work category having more favorable values than sedentary workers. However, substantial and significant differences were observed among employees classified on the basis of their LTPA, these differences being observed in both men and women. For instance, waist circumference, the cholesterol/HDL cholesterol ratio, triglyceride concentrations and resting heart rate were lower in active individuals compared to inactive and moderately inactive individuals (p < 0.01). Furthermore, irrespective of whether or not employees were sedentary at work, a high level of LTPA was associated with a greater CRF (p < 0.001). Finally, we found that the lowest prevalence of hypertriglyceridemic waist (p < 0.01) and the highest score of overall diet quality (p < 0.001) were observed in active individuals, irrespective of their OPA category. ConclusionLevels of LTPA were more strongly associated with cardiometabolic health than OPA in a cohort of blue- and white-collar employees. Furthermore, high levels of LTPA were found to counteract the potentially deleterious effects of a sedentary work on cardiometabolic health.

Abstract 14958: Association of Smartwatch-Based Resting Heart Rate With Cardiorespiratory Fitness Measures From Cardiopulmonary Exercise Test in the Community

Introduction: Resting heart rate (HR) is an established predictor of cardiorespiratory fitness. Commercial smartwatches permit remote HR monitoring in real world settings over long periods of time, but the relations of smartwatch measured HR and cardiorespiratory fitness in the general public remain uncharacterized. Objective We aimed to examine the associations of resting HR measured with a smartwatch in the electronic Framingham Heart Study (eFHS) with multi-dimensional fitness assessment via cardiopulmonary exercise test (CPET). We hypothesized that participants with lower resting HR would have greater cardiorespiratory fitness. Methods: eFHS participants were enrolled at an FHS research exam (2016-2019) and provided with a study smartwatch that collected longitudinal HR data for up to 3 years. We identified participants’ HR measures in the sedentary state through a classification algorithm to calculate the average resting HR for each participant. At the same exam, participants underwent CPET performed on a cycle ergometer. Multivariable linear models were used to test the association of resting HR with CPET indices. We used P&lt;0.05 for significance. Results: We included 1,051 participants (mean age 52±8 years, 59% women, mean resting HR 77±6 beats/min) with a median of 27,655 HR records for each individual, and median of 266 watch-wearing days. Higher individual resting HR was associated with a lower peak oxygen uptake (VO 2 ; both in ml/kg/min and % predicted), lower VO 2 at the ventilatory anaerobic threshold (VAT), higher (adverse) ventilatory efficiency (VE/VCO 2 ), and unfavorable blood pressure response to exercise (higher mean arterial pressure at 75 watts) ( Table ). Conclusions: Our findings suggest the feasibility of smartwatch-based HR assessment as an indicator of a broad array of cardiorespiratory fitness responses in the community, including measures of global fitness (peak VO 2 ), ventilatory efficiency, and blood pressure response to exercise.

Abstract 10538: Metabolite Profiling Highlights Links Between Healthy Diet and Greater Cardiorespiratory Fitness in the Community

Introduction: Cardiorespiratory fitness (CRF) is a powerful predictor of health outcomes, but its determinants are incompletely understood at the population level. Prior studies have suggested associations between dietary components and CRF, but they have generally been limited by small sample sizes, reliance on estimated CRF, variable dietary instruments, and lack of molecular interrogation to support shared biology. Hypothesis: Shared metabolite associations across dietary quality and CRF will prioritize metabolites potentially responsible for linking dietary quality with improved CRF in the community. Methods: Framingham Heart Study (FHS) participants underwent maximum effort cardiopulmonary exercise tests for quantification of CRF by peak oxygen uptake (VO 2 ) and completed food frequency questionnaires at a routine study visit. Dietary quality was assessed by the Mediterranean-style Diet Score (MDS), and fasting levels of 201 metabolites were quantified. Results: In 2380 FHS participants (age 54 ± 9 years, 54% women, BMI 28 ± 5 kg/m 2 ), a 1-SD higher MDS was associated with 4.4% (3.5% - 5.3%, p &lt; 0.0001) greater peak VO 2 in linear models adjusted for age, sex, cardiovascular risk factors, and physical activity. In a representative subsample that had metabolite profiling (N = 1154), 80 metabolites were statistically significantly associated with MDS, 57 with peak VO 2 , and 27 with both MDS and peak VO 2 in multivariable linear models (FDR &lt; 5% for all, Figure). These metabolites included dimethylguanidino valeric acid, medium chain acylcarnitines, and C16 ceramide, which are markers of insulin resistance and increased risk for cardiovascular disease. Metabolites with less established functions include C38:7 plasmalogens, which correlate with fish intake and may have anti-inflammatory effects. Conclusions: Healthy diet is associated with greater CRF in the community and may be partially explained by favorable metabolic health.

Profile of adults users of smartphone applications for monitoring the level of physical activity and associated factors: A cross-sectional study.

BackgroundThere are currently more than 200 million smartphones in Brazil. The potential of mobile technologies for favorable changes in health behavior such as physical activity has been previously described in the literature. Results of surveys in developed countries indicate that applications (APPs) are developed for people who are better educated, younger, and with higher incomes compared to non-users. However, the profile of users in developing countries like Brazil is not well-known. Understanding the profile of APP users might ease the development turned to physically inactive people and those at higher cardiovascular risk. Furthermore, the physiological and functional factors associated with the use of such APP are unknown.ObjectivesTo characterize the profile of APP users to monitor the physical activity level (PAL) and assess the demographic, socioeconomic, clinical, physiological, and functional characteristics associated with the use of smartphone APPs to monitor physical activity in Brazilian adults.MethodsWe assessed 176 asymptomatic men and 178 women (43 ± 12 years; 27 ± 5 kg/m2). We initially asked participants about their current use of a smartphone APP containing PAL monitoring functionality, such as exercise session logs and/or step counts. In a cross-sectional design, we investigated schooling, socioeconomic status (Critério Brasil), and classic self-reported cardiovascular risk factors. We evaluated several physiological and functional variables such as maximum O2 consumption on a treadmill (VO2 max), blood pressure, body composition (bioelectrical impedance), handgrip strength, and isokinetic muscle strength of the dominant lower limb. Participants used a triaxial accelerometer for 7 days to quantify daily physical activity. We also assessed health-related quality of life (WHOQOL BREF), perceived stress (PSS14 Scale), and the built environment (NEWS Scale). We compared continuous variables using the Student's t-test and categorical variables using the χ2 test, between APP users and non-users. After univariate analysis, we included the main variables associated with the use of APP in a multiple logistic regression model.ResultsOne hundred and two participants (28.3%), unrelated to gender, reported using a smartphone APP for physical activity at the time of assessment. Except for perceived stress and the built environment that were not associated with the use of APP, users of APP were younger and had higher education, lower cardiovascular risk, better socioeconomic status, a better quality of life, better cardiorespiratory function, better body composition, greater physical fitness and more moderate to vigorous physical activity in daily life. The results of the multiple logistic regression showed that age, hypertension, VO2 max, socioeconomic status (Critério Brasil), and quality of life (WHOQOL BREF total score) were the variables most significantly associated with the use of the APP.ConclusionsOur results indicate that smartphone APPs to monitor physical activity are developed for younger adults with better socioeconomic status, lower cardiovascular risk, higher quality of life, and greater cardiorespiratory fitness. Greater efforts are needed to develop a science-based APP for people who most need this technology, enabling greater potential to prevent undesirable health outcomes in asymptomatic adults.

Physical fitness and maternal body composition indices during pregnancy and postpartum: the GESTAFIT project

ABSTRACT We explored the association of physical fitness (PF) during pregnancy with maternal body composition indices along pregnancy and postpartum period. The study comprised 159 pregnant women (32.9 ± 4.7 years old). Assessments were carried out at the 16th and 34th gestational weeks (g.w.) and six weeks postpartum. Cardiorespiratory fitness (CRF), muscular strength (absolute and relative values) and flexibility were measured. Body composition indices were obtained by using dual-energy X-ray absorptiometry at postpartum. The results, after adjusting for potential covariates at the 16th g.w., indicated that greater CRF was associated with lower postpartum indices total fat mass, android and gynoid fat mass (all, p < 0.05). Greater absolute upper-body muscular strength was associated with greater pre-pregnancy body mass index (BMI), gestational weight gain (GWG); and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, gynoid fat mass, T-score and Z-score bone mineral density (BMD) (all, p < 0.05). Greater upper-body flexibility was associated with lower pre-pregnancy BMI; and postpartum indices body weight, BMI, lean mass, fat free mass, fat mass, android fat mass and gynoid fat mass, and with greater GWG (all, p < 0.05). At the 34th g.w., greater CRF was additionally associated with greater postpartum T-score and Z-score BMD (both, p < 0.05). In conclusion, this study reveals that greater PF levels, especially during early pregnancy, may promote a better body composition in the postpartum period. Therefore, clinicians and health promoters should encourage women to maintain or improve PF levels from early pregnancy.

Cardiorespiratory Fitness Level Alters Blood Pressure Responses Induced By Histamine H1- And H2-receptor Blockade During Dynamic Exercise

INTRODUCTION: Epidemiological studies have reported that greater cardiorespiratory fitness (CRF) is associated with lower blood pressure (BP). Histamine receptor-mediated peripheral vasodilation contributes to post-exercise hypotension and lowing exercising BP responses. Previously, our laboratory found that overactive BP responses to exercise were induced by the inability of histamine receptors in individuals with prehypertension. However, it is still unknown that CRF can impact BP responses elicited by the inability of the receptors. PURPOSE: This study was to assess whether aerobic fitness is effective in lowering excessive BP responses induced by the blockade of histamine receptors METHODS: In twelve male and female subjects (6 high CRF and 6 low CRF), we examined the effects of histamine H1- and H2- receptor blockades on heart rate (HR), stroke volume (SV), cardiac output (CO), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and total peripheral resistance (TPR) at workloads corresponding to 40% and 60% workloads of VO2peak during cycling exercise. RESULTS: Our study indicated that compared to the high CRF group, changes in MAP from the baselines were higher in the low CRF group before the blockade at each workload (40%: D14±2 vs. 8±1 mmHg; 60%: D21±3 vs. 15±2 mmHg). The changes in MAP in response to the blockade during exercise were substantially lower in the high CRF group (40%: D18±2 vs. 11±1 mmHg; 60%: D29±3 vs. 19±2 mmHg). CONCLUSIONS: Our study suggests that an improvement in CRF likely reduces exaggerated BP responses elicited due to the inability of histamine receptors in pathological conditions such as prehypertension and hypertension.

Midpoint of energy intake, non-fasting time and cardiorespiratory fitness in heart failure with preserved ejection fraction and obesity

BackgroundDelayed time of evening meal is associated with favorable cardiorespiratory fitness (CRF) in patients with heart failure with preserved ejection fraction (HFpEF) and obesity. It is unknown, however, if increasing daily non-fasting time or delaying the midpoint of energy intake may also be associated with CRF. ObjectiveOur aim was to examine whether a longer non-fasting time, delayed midpoint of energy intake, or both, are associated with greater CRF in patients with HFpEF and obesity. MethodsWe measured peak oxygen consumption (VO2), a measure of CRF, in 32 patients with HFpEF and obesity with cardiopulmonary exercise testing, and dietary intake using a five-pass 24-h dietary recall. Participants were divided into groups by having lesser (<11.6) or greater (≥11.6) periods of non-fasting time than the median and similarly, with earlier (<2:15 PM) or later (≥2:15 PM) than median midpoint of energy intake. ResultsMedian non-fasting time was 11.6 [10.6‐12.9] hours and midpoint of energy intake was 2:15 [1:04–3:00] PM. There were no differences in CRF between those with a shorter (<11.6) or longer (≥11.6) non-fasting time. Participants with a delayed midpoint of energy intake (≥2:15 PM) had greater peak VO2 and exercise time. Midpoint of energy intake (r = 0.444, P = 0.011) and time of last meal (r = 0.550, P = 0.001) displayed a positive association with peak VO2, but not non-fasting time nor time of first meal. ConclusionsDelaying the midpoint of energy intake by postponing last meal is associated with better peak VO2 and exercise time in patients with HFpEF and obesity.

Body composition, physical fitness and cardiovascular risk factors in 9-year-old children

The independent associations of body composition and physical fitness components with cardiovascular disease (CVD) risk factors in childhood are not fully understood. Thus, this cross-sectional study examined the independent associations of body composition and physical fitness with CVD risk factors in Swedish 9-year-old children (n = 411). Unadjusted linear regression analyses showed that body mass index (BMI), % fat mass and fat mass index were all positively associated with systolic and diastolic blood pressure, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Metabolic Syndrome (MetS) score (all β ≥ 0.229, P ≤ 0.001). These associations were virtually unaffected by adjustments for basic covariates (child’s age and sex, maternal educational level and maternal BMI), fat-free mass and physical fitness. Fat-free mass index had generally weak associations with CVD risk factors and no associations were statistically significant after adjustments (all P > 0.27). Greater cardiorespiratory fitness and motor fitness were associated with lower HOMA-IR and MetS score in unadjusted models (all β ≤ − 0.158, P ≤ 0.039) but not after adjustments for basic covariates and body composition. These findings indicate that cardiovascular health promotion in childhood may focus on the maintenance of a healthy fat mass.

Cardiorespiratory Fitness, BMI, Mortality, and Cardiovascular Disease in Adults with Overweight/Obesity and Type 2 Diabetes.

We estimated the effects of cardiorespiratory fitness (CRF) and body mass index (BMI) at baseline on mortality and cardiovascular disease events in people with type 2 diabetes who participated in the Look AHEAD randomized clinical trial. Look AHEAD compared effects of an intensive lifestyle intervention with diabetes support and education on cardiovascular disease events in 5145 adults age 45-76 yr with overweight/obesity and type 2 diabetes. In 4773 participants, we performed a secondary analysis of the association of baseline CRF during maximal treadmill test (expressed as metabolic equivalents (METs)) on mortality and cardiovascular disease events during a mean follow-up of 9.2 yr. The mean (SD) CRF was 7.2 (2.0) METs. Adjusted for age, sex, race/ethnicity, BMI, intervention group, and β-blocker use, all-cause mortality rate was 30% lower per SD greater METs (hazard ratio (HR) = 0.70 (95% confidence interval, 0.60 to 0.81); rate difference (RD), -2.71 deaths/1000 person-years (95% confidence interval, -3.79 to -1.63)). Similarly, an SD greater METs predicted lower cardiovascular disease mortality (HR, 0.45; RD, -1.65 cases/1000 person-years) and a composite cardiovascular outcome (HR, 0.72; RD, -6.38). Effects of METs were homogeneous on the HR scale for most baseline variables and outcomes but heterogeneous for many on the RD scale, with greater RD in subgroups at greater risk of the outcomes. For example, all-cause mortality was lower by 7.6 deaths/1000 person-years per SD greater METs in those with a history of cardiovascular disease at baseline but lower by only 1.6 in those without such history. BMI adjusted for CRF had little or no effect on these outcomes. Greater CRF is associated with reduced risks of mortality and cardiovascular disease events.

Relationship between TV watching during childhood and adolescence and fitness in adulthood in the Raine Study cohort

ABSTRACT To investigate: (1) whether TV watching habits throughout childhood and adolescence, a proxy of sedentary behaviour, impacted cardiorespiratory fitness (CRF) in adulthood, and (2) whether any potential impact of TV watching in childhood and adolescence on CRF in adulthood was changed by adult physical activity (PA) levels. A longitudinal study with questionnaire data available regarding TV watching collected at ages 5, 8, 10, 14, 17 and 20 yrs, allowed trajectories of TV watching to be developed. At age 28 yrs, participants completed a V̇O2peak test and the International Physical Activity Questionnaire. General linear models tested for differences in CRF (time to exhaustion TTE and V̇O2peak mL·kg−1·min−1) between TV watching trajectories. The secondary analysis tested the potential effect current PA levels has on the relationship between TV trajectory and fitness. In total, 449 participants [male n = 255 (56.8%), 28.3 ± 0.5 yrs; female n = 194 (43.2%), 28.2 ± 0.4 yrs] were included in the study. Three distinct trajectories of TV watching were identified: High TV, Increasing TV and Low TV. CRF was lowest in the High TV watching trajectory and increased progressively from High to Increasing TV and Increasing to Low TV (all P < .05). Within each of the TV trajectories, those engaging in high levels of current PA had greater CRF than those engaging in low and moderate PA. TV watching in childhood and adolescence negatively impacts upon adult fitness at the age of 28 years. However, this negative impact of historical TV watching on CRF can largely be attenuated by engaging in higher levels of PA in adulthood. Highlights High levels of TV watching during childhood and adolescence have negative downstream impacts on cardiorespiratory fitness in adulthood. Taking part in high levels of physical activity in adulthood partially reverses the negative impact of historical TV watching on adult fitness. Engaging in low levels of TV watching throughout childhood and adolescence does not protect individuals from the detrimental impact of low current physical activity levels. Our findings support important public health messages with relevance to parents, schools and government; to target low levels of sedentary time throughout the developmental years of life, whilst encouraging the adoption of regular physical activity across the lifespan including young adulthood.

Effects of fitness and sedentarism on a biomarker of early AD progression

AbstractBackgroundGiven the lack of an effective treatment for Alzheimer’s Disease (AD), research on factors that might prevent it or delay its symptoms is needed. Physical activity (PA) stands as a means for favourably altering cognitive performance and neuropathologic processes and has been identified as a relevant and easily modifiable lifestyle factor against AD progression. This study thrives to understand the effects of both cardiorespiratory fitness (CRF) and sedentary behaviours (SB) in adult controls through the assessment of magnetoencephalography (MEG).Method30 healthy adults (age between 50 and 70 years) participated in the study. The sample underwent a five minutes of eyes‐closed resting MEG recording (NMEG = 24), a cycloergometer incremental exercise test to evaluate CRF through VO2peak (Nstress = 17), and carried an accelerometer for one week to estimate SB (NACC = 26). The alpha peak frequency at posterior brain areas was extracted, and then its partial correlation to VOpeak and the relative sedentary time from the accelerometer data were calculated, respectively, while also controlling for age. Partial correlation between VO2max and relative sedentary time was calculated as well.ResultStatistical analysis yielded a significant direct correlation between VO2peak and Alpha peak frequency (N=17, rho = 0.504, p‐value = 0.023), while relative sedentary time and Alpha peak frequency showed a significant inverse correlation (N = 20, rho = ‐0.435, p‐value = 0.032). Partial correlation between VO2peak and relative sedentary time was not significant (N = 17, rho = ‐0.404, p‐value = 0.120).ConclusionDespite the small cohort, results pinpoint a strong influence of both CRF and SB. Greater CRF, described as higher VO2peak, appears associated with increased alpha frequency in posterior brain regions, a robust biomarker of brain health which is negatively affected in AD. At the same time, higher levels of sedentarism show a strong relation to decreased alpha peak frequency, indicating that low levels of PA might put subjects entering old age at risk.