Post-acute exercise cardiovagal modulation in older male adults with and without type 2 diabetes.

PURPOSE: We examined heart rate variability (HRV) and baroreflex sensitivity (BRS) disease- and age-related response at 10-and 60-min after an acute high-intensity interval (HIIE) and moderate continuous exercise (MICE) in older adults with and without type 2 diabetes mellitus (T2DM) and healthy young adults. METHODS: Twelve older male adults with (57-84 years) and without T2DM (57-76 years) and 12 healthy young male adults (20-40 years) completed an isocaloric acute bout of HIIE, MICE, and a non-exercise condition in a randomized order. Time and Wavelets-derived frequency domain indices of HRV and BRS were obtained in a supine position and offline over 2-min time-bins using Matlab. RESULTS: HIIE but not MICE reduced natural logarithm root mean square of successive differences (Ln-RMSSD) (d = - 0.85; 95% CI - 1.15 to - 0.55 ms, p < 0.001), Ln-high-frequency power (d = - 1.60; 95% CI - 2.24 to - 0.97 ms2; p < 0.001), and BRS (d = - 6.32; 95% CI - 9.35 to - 3.29 ms/mmHg, p < 0.001) in adults without T2DM (averaged over young and older adults without T2DM), returning to baseline 60 min into recovery. These indices remained unchanged in older adults with T2DM after HIIE and MICE. Older adults with T2DM had lower resting Ln-RMSSD and BRS than aged-matched controls (Ln-RMSSD, d = - 0.71, 95% CI - 1.16 to - 0.262 ms, p = 0.001; BRS d = - 3.83 ms/mmHg), 95% CI - 6.90 to - 0.76, p = 0.01). CONCLUSIONS: Cardiovagal modulation following acute aerobic exercise is intensity-dependent only in adults without T2DM, and appears age-independent. These findings provide evidence of cardiac autonomic impairments in older adults with T2DM at rest and following aerobic exercise.

Home- vs gym-based exercise delivery modes of two multicomponent intensity training regimes on cardiorespiratory fitness and arterial stiffness in adults with intellectual and developmental disability during the COVID-19 pandemic - a randomized controlled trial.

Background: We compared the effects of home- vs gym-based delivery modes of two 8-week supervised multicomponent intensity training regimes on cardiorespiratory fitness and arterial stiffness in 17 adults with intellectual and developmental disability during the COVID-19 pandemic. Methods: Participants were assigned to sprint interval training or continuous aerobic training, both incorporating resistance training. The intervention started with 8-weeks of online training (M1-M2), 1-month of detraining, plus 8-weeks of gym-based training (M3-M4). Results: Peak oxygen uptake decreased from M1-M2 and increased from M2-M4. Central arterial stiffness decreased between M1-M2, and M1-M4, along with peripheral arterial stiffness. Central systolic blood pressure decreased from M1-M2 only with sprint interval training. Conclusion: Home-based training minimized the negative impact of the lockdown on central arterial stiffness and central blood pressure, but it did not match the benefits on cardiorespiratory fitness and peripheral arterial stiffness of a gym-based intervention, irrespective of the multicomponent intensity training regime. Registered in ClinicalTrials.gov NCT05701943.

Cardiovagal Modulation in Young and Older Male Adults Following Acute Aerobic Exercise.

We compared response patterns of cardiovagal modulation through heart-rate variability (HRV) and baroreflex sensitivity (BRS) indices at 10 and 60 min after an acute bout of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) in active young and older adults. Twelve young (aged 20-40 years) and older (aged 57-76 years) healthy and active male adults performed an isocaloric acute bout of HIIE, MICE, or a non-exercise condition in a randomized order. HRV and BRS indices were analyzed offline with R-R intervals obtained from a supine position. HIIE decreased natural logarithm (Ln) standard deviation of NN intervals (d=-0.53; 95% CI: -0.77 to -0.30 ms, p<0.001), Ln-root mean square of successive differences (d=-0.85; 95% CI: -1.09 to -0.61 ms, p<0.001), Ln-high-frequency power (d=-1.60; 95% CI: -2.11 to -1.10 ms2; p<0.001), and BRS (d=-6.28; 95% CI: -8.91 to -3.64 ms/mmHg, p<0.001) after exercise in young and older adults, whereas MICE did not. Indices returned to baseline after 60 min. We found no evidence of age-associated response patterns in HRV or BRS to a single bout HIIE or MICE in active participants. HIIE reduced cardiovagal modulation in active young and older adults, returning to baseline values 60 min into recovery.

Acute effects of exercise on cardiac autonomic function and arterial stiffness in patients with stable coronary artery disease.

Objectives. To examine the acute effect of a maximal aerobic exercise effort on aortic, peripheral arterial stiffness and cardiovagal modulation of trained and untrained patients with coronary artery disease (CAD). Design. Cross-sectional study. Methods. Eighteen untrained patients with CAD, 18 trained patients with CAD, and 18 apparently healthy trained subjects were sampled and matched for age and body mass index. Aortic and peripheral stiffness were measured by applanation tonometry estimates of carotid-femoral (cfPWV), carotid-radial (crPWV), and carotid-dorsalis pedis pulse wave velocity (cdPWV), respectively. Cardiovagal modulation was assessed by heart-rate variability (HRV) indices including the standard deviation of normal-to-normal RR intervals (SDNN), root-mean-square of successive differences (RMSSD), and the high-frequency power band (HF). cfPWV, crPWV, cdPWV, and HRV indices were measured at rest, 10 and 30 min following a maximal cardiopulmonary exercise test on a cycle ergometer. Results. No differences were observed between groups at rest nor over time in indices of HRV, cfPWV and cdPWV. Still, main effects of time were observed in cfPWV (p < .001; ɳ2 = 0.313) and cdPWV (p = .003, ɳ2 = 0.111), RMSSD (p < .001, ɳ2 = 0.352), HF (p < .001, ɳ2 = 0.265) and LF/HF (p = .001, ɳ2 = 0.239), as cdPWV, RMSSD, and HF were reduced 10 min following exercise, whereas cfPWV and LF/HF were increased. Changes in cPP were associated with changes in HRV from rest to min 10 (HF, r = 0.302), and to min 30 (HF, r = 0.377; SDNN, r = 0.357; RMSSD, r = 0.429). Conclusion. Training level and CAD do not seem to influence arterial stiffness and cardiac autonomic responses to maximal exercise.

The effects of 12-months supervised periodized training on health-related physical fitness in coronary artery disease: a randomized controlled trial.

We compared the impact of a one-year periodized exercise training versus a non-periodized exercise training on health-related physical fitness (HRPF) including body composition, cardiorespiratory and muscular fitness in patients with coronary artery disease (CAD). Fifty CAD patients (60.4 ± 9.9 years) were randomized to either a periodized training group (PG) (n = 25) or a non-periodized training group (NPG) (n = 25). Both consisted of a combined training programme, performed 3 days/week for 12 months. Thirty-six CAD patients (PG: n = 18, NPG: n = 18) successfully completed the exercise regimes. In both groups, a favourable main effect for time was evident for peak VO2, peak workload, anaerobic threshold and respiratory compensation point workloads and VO2, whole body skeletal muscle mass and quality index at 12 months.In conclusion, a periodized model is as effective as a non-periodized model in promoting increases in HRPF outcomes following a one-year intervention. These findings indicate that health-professionals can add variation to cardiac rehabilitation workouts without compromising effectiveness.

Relationship of left ventricular global longitudinal strain with cardiac autonomic denervation as assessed by 123I-mIBG scintigraphy in patients with heart failure with reduced ejection fraction submitted to cardiac resynchronization therapy : Assessment of cardiac autonomic denervation by GLS in patients with heart failure with reduced ejection fraction submitted to CRT.

BACKGROUND: Heart failure (HF) is associated with cardiac autonomic denervation (AD), which can be non-invasively assessed by 123I-metaiodobenzylguanidine (123I-mIBG) scintigraphy and has prognostic implications. We aimed to study the relationship between myocardial contractility assessed by global longitudinal strain (GLS) and AD assessed by 123I-mIBG scintigraphy in advanced HF. METHODS/RESULTS: BETTER-HF is a prospective randomized clinical trial including HF patients (pts) submitted to cardiac resynchronization therapy (CRT) who are submitted to a clinical, echocardiographic, and scintigraphic assessment before and 6 months after CRT. 81 pts were included. An echocardiographic response (absolute increase in left ventricular ejection fraction ≥ 10%) was observed in 73.7% of pts. A higher baseline late heart-to-mediastinum ratio (HMR) was associated with a better echocardiographic response. There was a significant association between late HMR and GLS at baseline and 6 months. At baseline, GLS had an AUC of 0.715 for discrimination for a late HMR < 1.6. A GLS cut-off of - 9% maximized the likelihood of correctly classifying a pt as having severe AD (HMR < 1.6). CONCLUSION: Myocardial contractility as assessed by GLS is moderately correlated with AD as assessed by 123I-mIBG scintigraphy and has a good discrimination for the identification of severe cardiac denervation. GLS may allow for a more readily accessible estimation of the degree of AD in advanced HF pts.

A Post hoc analysis on rhythm and high intensity interval training in cardiac resynchronization therapy.

Objectives. Evaluate the effects of a 6-month High Intensity Interval Training (HIIT) program on (1) functional capacity and health-related quality of life, (2) multiple blood biomarkers, (3) echocardiographic parameters, and (4) exercise performance, in patients in cardiac resynchronization therapy (CRT) stratified by the presence of atrial fibrillation (AF), targeting the following questions: (1) Does CRT provide similar benefits in patients in AF and sinus rhythm (SR)?; and (2) Does HIIT provides similar benefits in patients in AF and SR? Design. Estimates were available at baseline and 6 months after CRT implantation in 37 patients with heart failure. Patients were randomized after CRT to a 24-week HIIT group or to a usual care group (CON). In this sub-analysis, HIIT (AF = 7; SR = 11) and CON (AF = 9; SR = 10) were stratified by the presence of AF. Results. Patients in AF benefitted to a lesser degree from CRT in functional status than patients in SR (23.8-46.0%). However, HIIT induced superior improvements in patients in AF compared to CON (23.9-61.0%). Decreases in TNF-α (8.5-42.9%), BNP (15.3-34.6%) and left ventricular mass (9.6-26.2%) were only observed in patients in SR, whereas increases in peak oxygen uptake were only observed in patients in AF (19.5-23.2%). HIIT improved exercise capacity (8.8-59.4%) in patients in SR. Conclusions. Patients in AF or SR undergoing CRT demonstrated distinct benefits from device implantation and from HIIT as an adjunctive therapeutic strategy. This suggests that both mainstay and adjunctive therapeutics may need to be managed differently in patients in AF and SR.

High-intensity interval training in cardiac resynchronization therapy: a randomized control trial.

AIMS: To determine the effects of high-intensity interval training (HIIT) following cardiac resynchronization therapy (CRT) implantation in patients with chronic heart failure (CHF), on noninvasive estimates of systolic ventricular function, exercise performance, severity of symptoms and quality of life. METHODS: Cardiopulmonary exercise testing, resting transthoracic echocardiogram and health-related quality of life assessment were obtained before and at 6 months after CRT implantation in 37 patients with moderate-to-severe CHF. Patients were randomized after CRT to either a 24-week HIIT group (90-95% peak heart rate, 2 days per week) or to a usual care group (CON). Mixed design 2 × 2 repeated measures ANOVA were used to test for differences within and in-between groups. RESULTS: Improvements in health-related quality of life (HIIT = 98.54%, CON = 123.47%), NYHA class (HIIT = 43.44%, CON = 38.30%) HR recovery at minute 1 (HIIT = 32.32%, CON = 42.94%), pulse pressure at peak effort (HIIT = 14.06%, CON = 9.52%, LVEF (HIIT = 42.17%, CON = 51.10%) and LV Mass (HIIT = 13.26%, CON = 11.88%) were similar in both groups (p > 0.05). Significant increases in CPET duration in the HIIT group (25.94%), and increases in peak VO2 (HIIT = 8.64%, CON = 4.85%) and percent-predicted VO2 (HIIT = 10.57%, CON = 4.26%) in both groups, were observed in the intention-to-treat analysis. CONCLUSION: Six months of HIIT in patients in CRT did not further improved indices of functional capacity and health-related quality of life, and LV structure and function, compared to CRT alone. However, HIIT led to further improvements in exercise performance. It remains unclear whether HIIT benefits patients in CRT to a similar degree as more conventional forms of exercise training previously shown to maximize benefits in CRT. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov . Unique identifier: NCT02413151.

Pulse pressure tracking from adolescence to young adulthood: contributions to vascular health.

PURPOSE: We examined whether exposure to high PP in adolescence predicts carotid artery intima-media thickness (IMT) and stiffness indices at young adulthood. METHODS: Seventy-nine participants had their brachial systolic (SBP) and diastolic blood (DBP) pressures taken at the age of 15-16 years and later at young adulthood (29-31 years). Carotid IMT, distensibility and stiffness index ß were measured at young adulthood. Linear and logistical regression analysis were performed. RESULTS: PP at adolescence and at young adulthood predicted vascular health independently of sex, body mass index, and mean arterial pressure, explaining up to 37% of the variance. When analyzing its single constituents, at adolescence DBP was more predictive of vascular health, whereas DBP and SBP were equally important at young adulthood. Adolescents with high PP were at risk for increased carotid IMT (OR: 4.04-4.09), even if PP decreased at young adulthood. Young adults with high PP were at risk for increased stiffness regardless of adolescence PP (OR: 4.64-7.35). CONCLUSION: PP at adolescence and young adulthood may be a better predictor of early pathological changes in carotid artery structure and stiffness. Whereas carotid IMT in young adults appears to be influenced by PP at adolescence, carotid stiffness depends primarily on current PP.

A 5-Year Follow-Up of The Benefits of an Exercise Training Program in Liver Recipients Transplanted Due to Familial Amyloidotic Polyneuropathy.

BACKGROUND: Supervised (SE) and home-based exercise (HBE) training regimes are effective on reconditioning patients with familial amyloidotic polyneuropathy (FAP) after liver transplantation, but research of the long-term retention of the benefits attained in patients with FAP has not yet been conducted. PURPOSE: In this 5-year follow-up study, we aimed to determine whether the exercise training gains in body composition, physical activity, and function promoted by a 24-week SE or HBE training regimes are retained in patients with FAP who resume normal activity. METHODOLOGY: Sixteen liver-transplanted patients with FAP were reassessed for body composition (dual X-ray absorptiometry), physical activity (questionnaire), and function (handgrip strength and 6-minute walk test). RESULTS: Total body fat increased with both exercise regimes during follow-up ( P < .05; η2 = 0.432-0.625) as well as femoral neck bone density ( P = .048; η2 = 0.119). However, gains in upper limbs muscle quality during follow-up ( P < .001; η2 = 0.597) were only found in the SE group ( P = .042; η2 = 0.245). Both exercise regimes showed retaining aptitudes in walking capacity ( P < .05; η2 = 0.329-0.460) and muscle mass ( P = .05; η2 = 0.245). Still, none could retain the physical activity levels. CONCLUSION: Long-term resumption of normal activity following a 24-week SE or HBE regime in patients with FAP resulted in loss of exercise induced increases in physical activity but counterweighted postoperative losses in bone mineral density and substantially retained the benefits in walking capacity, muscle mass, and quality, in particular, in the SE group.

Waist-to-Hip Ratio is Related to Body Fat Content and Distribution Regardless of the Waist Circumference Measurement Protocol in Nonalcoholic Fatty Liver Disease Patients.

Central accumulation and distribution of body fat (BF) is an important cardiometabolic risk factor. Waist-to-hip ratio (WHR), commonly elevated in nonalcoholic fatty liver disease (NAFLD) patients, has been endorsed as a risk related marker of central BF content and distribution, but no standardized waist circumference measurement protocol (WCmp) has been proposed. We aimed to investigate whether using different WCmp affects the strength of association between WHR and BF content and distribution in NAFLD patients. BF was assessed with dual energy X-ray absorptiometry (DXA) in 28 NAFLD patients (19 males, 51 ± 13 years, and 9 females, 47 ± 13 years). Waist circumference (WC) was measured using four different WCmp (WC1: minimal waist; WC2: iliac crest; WC3: mid-distance between iliac crest and lowest rib; WC4: at the umbilicus) and WHR was calculated accordingly (WHR1, WHR2, WHR3 and WHR4, respectively). High WHR was found in up to 84.6% of subjects, depending on the WHR considered. With the exception of WHR1, all WHR correlated well with abdominal BF (r = .47 for WHR1; r = .59 for WHR2 and WHR3; r = .58 for WHR4) and BF distribution (r = .45 for WHR1; r = .56 for WHR2 and WHR3; r = .51 for WHR4), controlling for age, sex and body mass index (BMI). WHR2 and WHR3 diagnosed exactly the same prevalence of high WHR (76.9%). The present study confirms the strong relation between WHR and central BF, regardless of WCmp used, in NAFLD patients. WHR2 and WHR3 seemed preferable for use in clinical practice, interchangeably, for the diagnosis of high WHR in NAFLD patients.

Imaging predictive factors and exercise training in CRT patients.

Cardiac resynchronization therapy (CRT) is an established treatment for patients with moderate-to-severe chronic heart failure (CHF) and intraventricular conduction delay, which is identified by a QRS interval of 120msec or more on a 12-lead electrocardiogram (ECG). CRT improved functional capacity, reduced hospitalizations for worsening CHF and increased survival. However, about 30-40% of patients who underwent CRT were non-responders with no clinical or echocardiographic improvement. Imaging parameters for prediction of CRT response have been reviewed. Cardiac magnetic resonance (CMR), recognized as the gold standard to assess viability, has shown to obtain good results regarding quantification of scar burden. CMR-derived measures of mechanical dyssynchrony appear to predict the outcome of CRT, however they have not been externally validated. Nuclear imaging techniques, namely single-photon emission cardiac tomography (SPECT) provide data on scar burden and location, left ventricular (LV) function, LV contraction and mechanical dyssynchrony from a single scan. The presence, location and burden of myocardial scar have been shown to affect response to CRT. However, compared to CMR, the low spatial resolution of scintigraphy might overestimate the scar extent. This problem can be overcome by positron emission tomography (PET). SPECT has also been used to quantify dyssynchrony, using phase analysis. Imaging investigation is ongoing, trying to better identifying CRT non-responders. The combination of ExT in CRT has not been well investigated; however some data show different aerobic exercise modes and intensities can further improve CRT benefits. Data available on the effects of ExT in patients with CRT have been reviewed.

Body composition phenotypes and carotid intima-media thickness in 11-13-year-old children.

UNLABELLED: Early detection of impairment in vascular structure is an important clinical pursuit. However, it is unknown which measure of body composition best predicts vascular wall changes. We assess the differences in body composition among intima-media thickness (IMT) tertiles and determined which measures of body composition are associated with IMT in 385 children aged 11-13 years (196 girls). In this cross-sectional study, body mass index (BMI), waist circumference (WC), body fat mass (BFM), and trunk fat mass (TFM) from dual-energy radiographic absorptiometry and IMT through high-resolution ultrasonography were collected. Differences in body composition measures among IMT tertiles [low IMT (LIMT), ≤ 0.46 mm; middle IMT, 0.46-0.53 mm; higher IMT (HIMT), ≥0.53 mm] were assessed with ANOVA/ANCOVA after categorization. Regression analysis was used to assess the relationships between body composition and IMT. The groups were similar for sex, age, and maturity (p > 0.05). As compared with LIMT group, subjects with HIMT had higher mean values of BMI, BFM, TFM, and WC (p < 0.05). Significant differences were found for WC even when controlling for BMI (p < 0.05). Combining all subjects, IMT was significantly correlated to BMI, BFM, TFM, and WC (p < 0.05). In multiple regression, WC was the only predictor of IMT (ß = 0.22, p < 0.001). CONCLUSION: Differences exist in body composition variables among IMT tertiles. In the overall model, WC was the only obesity-related predictor of increased IMT in 11-13-year-old children.

Intra and inter-rater repeatability of brachial artery ultrasound estimates of flow-mediated slowing and flow-mediated dilation.

Flow-mediated slowing (FMS) is a non-invasive measure of endothelial function measured through reactive hyperemia-induced changes in pulse wave velocity (PWV). FMS is suggested to mitigate known pitfalls of flow-mediated dilation (FMD) including suboptimal repeatability and high-operator dependency. However, the few single-rater studies that examined FMS repeatability have shown controversial results and used only regional measurements of PWV, which might not reflect local brachial artery stiffness responses to reactive hyperemia. We assessed the inter- and intra-rater repeatability of ultrasound-based changes in local PWV (FMS) and diameter (FMD). Twenty-four healthy male participants aged 23-75 yr, were examined on two separate days. Reactive hyperemia-induced changes in PWV were calculated using a tailored R-script. The inter- and intra-rater repeatability were tested with the intraclass correlation coefficient (ICC), coefficient of variation (CV), and the Bland-Altman plot estimates. The inter-rater repeatability of FMS (bias: -0.08%; ICC: 0.85; 95% CI: 0.65 to 0.93; CV: 11%) and FMD (bias: -0.02%; ICC: 0.98; 95% CI: 0.97 to 0.99; CV: 7%) showed overall good repeatability over different days. The intra-rater repeatability of FMD (1st rater: bias: 0.27%; ICC: 0.90; 95% CI: 0.78 to 0.96; CV: 14%; 2nd rater: bias: 0.60%; ICC: 0.85; 95% CI: 0.64 to 0.94; CV: 18%) was better than FMS (1st rater: bias: -1.03%; ICC: 0.76; 95% CI: 0.44 to 0.91; CV: 21%; 2nd rater: bias:-0.49%; ICC: 0.70; 95% CI: 0.34 to 0.80; CV: 23%) but not different between raters. Ultrasound-based local measurements of PWV deceleration reactive hyperemia were repeatable among the raters.

Comparison of Acute Arterial Responses Following a Rescue Simulation and Maximal Exercise in Professional Firefighters.

Cardiovascular events are the leading cause of on-duty deaths among firefighters. Screening firefighters for risk of sudden cardiac event is a critical element of a comprehensive medical program. Although intense physical exertion has been shown to trigger sudden cardiac events in the general population, it is unclear how hemodynamic responses following clinical exercise testing compare to that of performing firefighting tasks in personal protective equipment. Therefore, the purpose of this study was to compare hemodynamic responses following rescue simulation (RS) and maximal exercise in firefighters. This was a cross-over repeated measures study. Thirty-eight professional firefighters (31.8 ± 5.2 yr; VO2peak: 57.9 mL/kg/min) completed a maximal aerobic exercise test (MAET) and an RS. Pulse wave velocity (PWV), pulse pressure (PP), and brachial and central mean arterial pressure (MAP) were measured before and 5 and 15 min post-exercise. The findings indicated that femoral PWV decreased after MAET and RS at both time points (p < 0.005). No significant differences were found in aortic and carotid PWV over time or between conditions (p ≥ 0.05). Significant increases in brachial and central PP and MAP were noted 5 min post-MAET and RS (p = 0.004). In conclusion, the present study demonstrated that peripheral arterial stiffness (AS) decreased in firefighters following both conditions, with no differences in central AS. Our findings provide valuable information on hemodynamic responses similar between RS and MAET, and are important for controlling CVD risk and the AS response.

Effects of kettlebell swing training on cardiorespiratory and metabolic demand to a simulated competition in young female artistic gymnasts.

We examined the effects of adding a Kettlebell Swing training program (KB) to the regular skill-training protocol (REGULAR) on cardiorespiratory fitness, cardiorespiratory/metabolic demand, and recovery to a simulated competition of female artistic gymnastics. Nine gymnasts (13±2 years) had their REGULAR complemented with a 4-week kettlebell training (REGULAR+KB), consisting of 3 sessions/week of 12x30" swings x 30" rest with » of their body weight, while 9 aged-matched gymnasts acted as a comparison group. Peak oxygen uptake ([Formula: see text]) during routines was estimated from the O2 recovery curve using backward extrapolation and off-kinetics parameters were modeled through a mono-exponential function. Heart rate (HR) was monitored continuously and capillary blood lactate (BLa-) was measured before and after each routine (1st and 3rd min). Cardiorespiratory fitness ([Formula: see text]) was evaluated using a ramp cycle ergometer test. A training-by-time interaction effect was observed for [Formula: see text] (p = 0.009) as increments were only observed after REGULAR+KB (M = 8.85, SD = 9.67 ml.kg.min-1). No training-by-time interactions were observed for HRpeak (p = 0.39), [Formula: see text] (p = 0.07), or La-post3 (p = 0.25), both training protocols reduced HRpeak (M = -12; SD = 11 b.min-1) and BLa-post1 (M = -0.70; SD = 1.29 mmol.L-1) during the simulated competition, but not relative [Formula: see text]. No training-by-time interaction was observed for the off-transient [Formula: see text] time constant (p = 0.38). [Formula: see text] recovery was slower (M = 5; SD = 10 s) after both protocols. Both training protocols improved cardiorespiratory and metabolic demands and recovery kinetics to a simulated competition of female artistic gymnastics, although increases in cardiorespiratory fitness were only observed in REGULAR+KB.

The role of lean body mass and physical activity in bone health in children.

In the context of physical education curricula, markers of physical fitness (e.g., aerobic capacity, muscular strength, flexibility, and body mass index or body fat) are usually evaluated in reference to health standards. Despite their possible mediating role in the relationship between weight-bearing or muscle forces and features of bone tissue, these attributes of fitness may not be the most relevant to predict skeletal health. It is therefore important to analyze the relative contribution of these factors to the variability in bone tissue of different parts of the skeleton, and to analyze it by gender, as sensitivity to mechanical loading can diverge for boys and girls. We compared the effects of habitual physical activity (PA) and lean mass, as surrogates of weight-bearing and muscle forces, and of physical fitness (aerobic and muscle capacity of lower and upper limbs) on bone mineral content (BMC) and size of total body, lumbar spine, femoral neck, and 1/3 radius in 53 girls and 64 boys from 7.9 to 9.7 years of age. After controlling for bone age, body mass, body height, and calcium intake, lean mass was the most important predictor of bone size and/or mineral in both genders (p < 0.05), while habitual weight-bearing PA positively influenced BMC in boys (p < 0.05). The effect of muscle in bone was not determined by PA and fitness score did not explain bone variability. Femoral neck was the bone site more closely associated with mechanical loading factors; boys with a PA > 608 counts/min/day (~105 min/day of moderate and vigorous intensity) showed 13-20% more BMC than those with less physical activity, and girls with a lean mass >19 kg showed 12-19% more BMC than those with less lean mass. These findings suggest that lean mass was the most important predictor of bone size and/or mineralization in both genders, while habitual weight-bearing PA appears to positively impact on bone mineral in prepubertal boys and that both lean mass and PA need to be considered in physical education curricula and other health-enhancing programs.

Cardiovascular fitness and cardiovascular risk factors among obese men and women aged 58 years and older, in Portugal.

BACKGROUND: A better physical fitness may have survival advantages in adults. AIM: To analyze the relationship between cardiorespiratory fitness and cardiovascular risk factors among obese subjects aged 58 years and older. MATERIAL AND METHODS: Cardiorespiratory fitness using the six-minute walk test, body composition by dual-energy x-ray absorptiometry and blood pressure were measured in a non-representative sample of 76 obese Portuguese subjects aged 58 to 87 years (55 women). Participants were stratified in tertiles of walking capacity according to the six-minute walk test. RESULTS: Six minutes walk test results were negatively correlated with percentage body fat (r = -0.28; p = 0.012) and systolic blood pressure (r = -0.23; p = 0.045). Participants located in the lowest tertile for the six minutes walk test had an odds ratio of 4.34 (95% confidence intervals: 1.02-18.43) for elevated blood pressure. CONCLUSIONS: A lower six minutes walk test result is associated with a higher risk for high blood pressure.

Flow-mediated slowing shows poor repeatability compared with flow-mediated dilation in non-invasive assessment of brachial artery endothelial function.

Pulse wave velocity (PWV) deceleration to reactive hyperemia-flow-mediated slowing (FMS)-has been suggested as an alternative method to flow-mediated dilation (FMD) to evaluate brachial artery endothelial function. FMS is suggested to address major caveats of the FMD procedure including its suboptimal repeatability and high-operator dependency. However, the repeatability of FMS has not been thoroughly examined, especially given the plethora of methods claiming to measure PWV. We assessed and compared the intra- and inter-day repeatability of FMS as measured by piezoelectric pressure mechanotransducers placed in the carotid and radial arteries, and brachial artery FMD as measured by echo-tracking. Twenty-four healthy male participants aged 23-75 yr, were examined on three separate days to assess intra and inter-day repeatability. All FMD and FMS examinations were conducted simultaneously by the same researcher complying with standardized guidelines. Repeatability was examined with intraclass correlation coefficient (ICC; >0.80), coefficient of variation (CV; <15%), and limits of agreement (95% LOA). Relative (%) FMD and FMS were scaled for baseline brachial artery diameter and PWV, respectively. Intra- (ICC: 0.72; CV: 136%; 95% LOA: -19.38 to 29.19%) and Inter-day (ICC: 0.69; CV: 145%, 95% LOA: -49.50 to 46.08%) repeatability of %FMS was poor, whereas %FMD demonstrated moderate-to-good intra- (ICC: 0.93; CV: 18%, 95% LOA: -3.02 to 3.75%) and inter-day repeatability (ICC: 0.74; CV: 25%, 95% LOA: -9.16 to 7.04%). Scaling FMD reduced the intra-day CV (-5%), and the uncertainty of the 95% LOA (- 37.64 to 35.69%) estimates of FMS. Carotid-radial artery FMS showed poorer repeatability compared to FMD.

Arterial Stiffness Response to Acute Combined Training with Different Volumes in Coronary Artery Disease and Heart Failure Patients.

Resistance training has been shown to acutely increase arterial stiffness (AS), while endurance training appears to decrease AS. However, the findings are from studies in apparently healthy subjects and have limited applicability to patients at low and high cardiovascular risk, for whom combined exercise is recommended. We compared the time course of changes in local and regional indices of AS in response to high-volume combined endurance training (CET) and high-volume combined resistance training (CRT) in patients with coronary artery disease (CAD) and heart failure (HF). We studied 20 men with CAD and HF (10 each) aged 68.3 ± 9.6 years. AS was measured by pulse wave velocity (PWV), and brachial and central blood pressure (BP) were determined after 15 min of rest and 5 and 15 min after the exercise session. All patients completed two sessions on nonconsecutive days. A protocol by time interaction effect was observed for carotid (η2 = 0.21, p = 0.02), aortic (η2 = 0.60, p < 0.001), and femoral (η2 = 0.46, p = 0.01) PWV after CET and CRT, suggesting that PWV decreased after CET and increased after CRT. Decreases in the brachial and central variables of BP across time points were observed in both protocols. CET decreased whereas CRT increased carotid, aortic, and femoral PWV at 15 min after exercise in patients with CAD and HF.