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Purpose: To compare the energetic contribution and pacing in 2000- and 1500-m maximal rowing-ergometer performances. Methods: On separate visits (>48 h apart, random order), 18 trained junior (16.7 [0.4] y) male rowers completed 3 trials: a 7 × 4-minute graded exercise test, a 2000-m time trial (TT2000), and a 1500-m TT (TT1500). Respiratory gases were continuously measured throughout each trial. The submaximal power-to-oxygen-consumption relationship from the graded exercise test was used to determine the accumulated oxygen deficit for each TT. Differences in mean power output (MPO), relative anaerobic contribution, percentage of peak oxygen uptake, pacing index, maximum heart rate, rating of perceived exertion, and blood lactate concentration were assessed using linear mixed modeling. Results: Compared to TT2000 (324 [24] W), MPO was 5.2% (3.3%) higher in TT1500 (341 [29 W]; P <.001, η p 2 =.70). There was a 4.9% (3.3%) increase (P <.001, η p 2 =.71) in anaerobic contribution from 17.3% (3.3%) (TT2000) to 22.2% (4.3%) (TT1500). Compared to TT1500, maximum heart rate, rating of perceived exertion, and blood lactate concentration were all greater (P <.05) in TT2000. The pacing index was not different between trials. Percentage increase in MPO from TT2000 to TT1500 was negatively associated with pacing variance in TT1500 (R2 =.269, P =.027). Conclusions: Maximal ergometer performance over 1500 m requires a significantly greater anaerobic contribution compared with 2000 m. Junior male athletes adopt a consistent pacing strategy across both distances. However, those who experienced greater percentage increases in MPO over the shorter test adopted a more even pacing strategy. To prepare for 1500-m performance, greater emphasis should be placed on developing capacity for work in the severe domain and completing race simulations with a more even pacing strategy. [ABSTRACT FROM AUTHOR]

People with HIV (PWH) are at increased risk for metabolic disorders affecting body mass index (BMI), chronic symptoms, and impaired physical function and capacity. Although physical activity improves health and well-being, PWH often do not meet activity recommendations necessary to achieve these benefits. Despite the known impact of symptoms, physical activity, and physical function on health, little is known about the relationships and interactions between these variables and BMI and maximum oxygen consumption during exercise (VO2 max) in a multinational population of PWH. We examined the relationship of BMI with PROMIS-29 measures, physical activity, strength, flexibility, and VO2 max in a diverse sample of PWH. Additionally, we examined the relationship of VO2 max with PROMIS-29 measures. Data from 810 PWH who participated in a cross-sectional study conducted by the International Nursing Network for HIV Research (Study VII) were analyzed. Participants were recruited from 8 sites across the United States, Thailand, and South Africa. BMI was calculated from collected height and weight data. Physical function and symptoms were assessed using the PROMIS-29 measure. Physical activity was assessed using the 7-day Physical Activity Recall. VO2 max was calculated using sex at birth, age, BMI and the 6-minute Walk Test. Data were analyzed using descriptive, correlational, and regression statistical analyses. Participants had an average age of 49.1 (± 11.1) years, 44% were female, and the average BMI of the sample group was 27 kg/m2 (± 6.7). Increased BMI was associated with decreased 6-minute Walk Test (β=-2.18, p < 0.001), flexibility (β=-0.279, p < 0.001), and VO2 max (β=-0.598, p < 0.001), even after controlling for covariates (age, sex at birth, country, years living with HIV, and antiretroviral therapy status). BMI was not associated with self-reported physical activity. Increased VO2 max was associated with increased physical function (β = 0.069, p < 0.001), and decreased pain (β=-0.047, p < 0.006), even after controlling for covariates (country, years living with HIV, and antiretroviral therapy status). Future research should explore development of effective and sustainable symptom self-management interventions in PWH accounting for the potential impact of BMI and VO2 max. [ABSTRACT FROM AUTHOR]

Objective: This study examined relationships between physical fitness, health behaviors, and occupational outcomes of university affiliates. Participants: 166 university affiliates of an American university (including students, faculty, and staff) participated between October 2018 and March 2020. Methods: Participants completed fitness measurements, wore a device to measure physical activity (PA) and sleep for one week, and completed a survey evaluating happiness and job satisfaction. Multiple regression models evaluated associations between physical fitness, health behaviors, and occupational outcomes. Results: 45% of participants had "poor" cardiorespiratory fitness (CRF) and unhealthy % fat. CRF, body composition, and muscular endurance were related to PA while body composition was related to sleep duration. Muscular endurance was related to GPA and job satisfaction. Conclusions: Findings suggest 45% of university affiliates had deficient physical fitness and may benefit from increasing PA and sleep. Universities should evaluate fitness within holistic programs to improve affiliates' health and, ultimately, occupational success. [ABSTRACT FROM AUTHOR]

Objective This study aimed to determine the effects of inspiratory muscle training (IMT) on exercise capacity, respiratory muscle strength, length of hospital stay (LOS), and quality of life (QOL) following coronary artery bypass graft surgery. Methods The search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Handbook and included the databases MEDLINE, EMBASE, CINAHL, Scopus, and CENTRAL. The review included randomized controlled trials utilizing IMT during phase 1 or 2 postoperative cardiac rehabilitation (PoCR) versus alternative treatment (active or passive control) in patients following coronary artery bypass graft surgery. Results Fifteen studies were included (11 phase 1 studies, 4 phase 2 studies) with no reported adverse events. In phase 1 PoCR, IMT reduced the LOS (−1.02 days; 95% CI = −2.00 to −0.03) and increased exercise capacity (6-minute walk distance) (+75.46 m; 95% CI = 52.34 to 98.57), and maximal inspiratory pressure (MIP) (10.46 cm H2O; 95% CI = 2.83 to 18.10), but had no effect on maximal expiratory pressure. In phase 2 PoCR, IMT increased 6-minute walk distance (45.84 m; 95% CI = 10.89 to 80.80), MIP (−23.19 cm H2O; 95% CI = −31.31 to −15), maximal expiratory pressure (20.18 cm H2O; 95% CI = 9.60 to 30.76), and QOL (−11.17; 95% CI = −17.98 to −4.36), with no effect on peak oxygen uptake. There was a high risk of bias for MIP (75% of the phase 1 studies) and 6MWT (1 of 4 phase 2 studies). The quality of the evidence ranged from very low to moderate. Conclusion IMT significantly improves exercise capacity, respiratory muscle strength, LOS, and QOL in phase 1 and 2 PoCR. Impact IMT may benefit patients during phase 1 and 2 of PoCR, considering the safety, low cost, and potential benefits. [ABSTRACT FROM AUTHOR]

Objective: The Pacific Lamprey Entosphenus tridentatus is considered a first food of Native American tribes, such as the Confederated Tribes of the Umatilla Indian Reservation. Populations of this imperiled species have declined such that harvest for traditional use is limited. As a result, propagation and culture of Pacific Lampreys have been initiated to supply animals for restoration and recovery efforts. These efforts require transport and periodic holding of both adults and larvae under static (no‐flow) conditions. Hence, guidelines for ensuring an adequate oxygen supply are needed for all life stages of this species. Methods: We measured oxygen consumption rates of mature adults, first‐feeding larvae, and yearlings under static conditions at 12–15°C. In addition, we recorded indicators of stress during hypoxia for adults and estimated routine respiration rates during and after larval feeding. Result: Adults exhibited surprisingly high metabolic rates when at rest in static chambers. At 12°C, a single adult typically reduced dissolved oxygen levels in 10 L to <2 mg/L in just 90 min (oxygen consumption rates of 100–200 mg/kg/h). Adults often started to climb the walls of open chambers when dissolved oxygen levels approached 2 mg/L, allowing them to raise their branchiopores into air. Larvae remained quiescent, even when oxygen levels dropped below 1 mg/L, and costs of feeding increased routine respiration by 22–56%. Conclusion: Based on these observations, we recommend that adult Pacific Lampreys always be transported in aerated containers and with access to air at the top of the tank. Although larvae exhibited hypoxia tolerance, care should be taken to ensure adequate oxygen availability, particularly during and immediately after feeding. Impact statementPacific Lamprey are a valued cultural resource for Native American tribes of the northwestern United States and provide critical ecosystem services. To protect these fish during transport and rearing, we studied the oxygen requirements of both sexually mature adults and larvae. Based on these experiments, we recommend that adult Pacific Lamprey always be transported in aerated containers with access to air at the top of the tank. Larvae can increase their oxygen requirements by over 50% during feeding. For this reason, care should be taken to insure adequate oxygen supply in no‐ or low‐flow conditions, particularly during feeding. [ABSTRACT FROM AUTHOR]

There is a general lack of information about how insufficient physical activity impacts blood pressure and physical fitness in Latin-American ethnic minorities. To describe the interactions between insufficient physical activity, blood pressure, and physical fitness outcomes in Latin-American schoolchildren of different ethnicity. This was a prospective, international, multi-center, and cross-sectional study of three Latin-American countries involving schoolchildren from seven ethnic groups of Colombia (Tikuna, Nasa, Embera), Brazil (African, Mulato), and Chile (Mapuche), and also European schoolchildren from Brazil and Chile. Data were categorized based on whether participants were physically active (PA) or insufficient physical activity (iPA) using the WHO physical activity recommendations. The main outcomes were systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure, and scores for physical and cardiorespiratory fitness (CRF, by estimated V ˙ O2max), handgrip muscle strength (HGS), and standing long jump (SLJ). Secondary outcomes were anthropometric measures (weight, height, body mass index [BMI], waist circumference [WC], waist-to-height ratio), and body fat percentage (BF%, limited data by country). Primary and secondary outcomes were ranked. For both PA and iPA categories, significant interactions between ethnic groups were found concerning SBP/DBP (F(37.7), ES 0.08; F(51.5), ES 0.08), V ˙ O2max (F(37.7), ES 0.08; F(51.5), ES 0.08), HGS (F(33.8), ES 0.07; F(5.03), ES 0.04), and SLJ (F(64.3), ES 0.14; F(64.3), 0.14). In the iPA category, Mapuche schoolchildren were classified 1st (119.5; 81.5) with highest SBP/DBP and highest MAP (94.6 mmHg); Embera schoolchildren were classified 1st with lowest V ˙ O2max (33.7 mL/kg/min); and European schoolchildren were classified 1st (19.9 kg) with lowest HGS and SLJ (121.4 m) physical fitness. Under conditions of insufficient physical activity conditions, Mapuche schoolchildren had the most detrimental blood pressure, whereas Embera, Tikuna, and European schoolchildren had the lowest levels of physical fitness. These results serve to highlight the need for the early and appropriate promotion of physical activity based on ethnic differences in Latin-American schools. [ABSTRACT FROM AUTHOR]

Purpose: Sedentary behavior is associated with poor physical function in older adults, which can lead to accelerated skeletal muscle aging (sarcopenia) and premature mortality. We examined the independent and joint effects of sedentary behavior and moderate to vigorous intensity physical activity (MVPA) with measures of physical functioning. Methods: We studied 5408 participants in the REasons for Geographic and Racial Differences in Stroke study who wore a hip-mounted accelerometer over seven consecutive days (2009–2013) and had self-reported and directly observed physical function (time walk, chair stand test) measured during an in-home visit conducted from 2013 to 2016. Results: Greater sedentary time was significantly associated with poorer chair stand and timed walk scores. Substituting 30 min of sedentary time with 30 min of MVPA was associated with significant improvements in chair stands (β −0.57; P = 0.007) and timed walk (β −0.36; P = 0.01). Similar, but less robust, findings were observed for reallocations of sedentary time to light-intensity physical activity. In joint association analyses, high sedentary time in combination with low MVPA (but not in combination with high MVPA) was associated with poorer physical function compared with the referent group (low sedentary time/high MVPA; P < 0.001 for all). Conclusions: Greater time spent being sedentary was associated with worse physical functioning outcomes. However, reallocations of sedentary time to light-intensity physical activity, and especially MVPA, were associated with more favorable physical functioning. Interventions aimed to increase MVPA and reduce sedentary behavior should be a priority, especially among populations at greatest risk for sarcopenia and physical function decline. [ABSTRACT FROM AUTHOR]

Figueiredo, PS, Looney, DP, Pryor, JL, Doughty, EM, McClung, HL, Vangala, SV, Santee, WR, Beidleman, BA, and Potter, AW. Verification of maximal oxygen uptake in active military personnel during treadmill running. J Strength Cond Res 36(4): 1053-1058, 2022-It is unclear whether verification tests are required to confirm "true" maximal oxygen uptake (V[Combining Dot Above]O2max) in modern warfighter populations. Our study investigated the prevalence of V[Combining Dot Above]O2max attainment in U.S. Army soldiers performing a traditional incremental running test. In addition, we examined the utility of supramaximal verification testing as well as repeated trials for familiarization for accurate V[Combining Dot Above]O2max assessment. Sixteen U.S. Army soldiers (1 woman, 15 men; age, 21 +/- 2 years; height, 1.73 +/- 0.06 m; body mass, 71.6 +/- 10.1 kg) completed 2 laboratory visits, each with an incremental running test (modified Astrand protocol) and a verification test (110% maximal incremental test speed) on a motorized treadmill. We evaluated V[Combining Dot Above]O2max attainment during incremental testing by testing for the definitive V[Combining Dot Above]O2 plateau using a linear least-squares regression approach. Peak oxygen uptake (V[Combining Dot Above]O2peak) was considered statistically equivalent between tests if the 90% confidence interval around the mean difference was within +/-2.1 ml[middle dot]kg-1[middle dot]min-1. Oxygen uptake plateaus were identified in 14 of 16 volunteers for visit 1 (87.5%) and all 16 volunteers for visit 2 (100%). Peak oxygen uptake was not statistically equivalent, apparent from the mean difference in V[Combining Dot Above]O2peak measures between the incremental test and verification test on visit 1 (2.3 ml[middle dot]kg-1[middle dot]min-1, [1.3-3.2]) or visit 2 (1.1 ml[middle dot]kg-1[middle dot]min-1 [0.2-2.1]). Interestingly, V[Combining Dot Above]O2peak was equivalent, apparent from the mean difference in V[Combining Dot Above]O2peak measures between visits for the incremental tests (0.0 ml[middle dot]kg-1[middle dot]min-1 [-0.8 to 0.9]) but not the verification tests (-1.2 ml[middle dot]kg-1[middle dot]min-1 [-2.2 to -0.2]). Modern U.S. Army soldiers can attain V[Combining Dot Above]O2max by performing a modified Astrand treadmill running test. Additional familiarization and verification tests for confirming V[Combining Dot Above]O2max in healthy active military personnel may be unnecessary. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to examine the relationships among waist-to-height ratio (WHtR), aerobic fitness, and cardio-melabolic risk factors in Hispanic children from low-income U.S. schools. Method: Participants were 198 Hispanic children from low-income schools (Mean age = 10.3 ± 0.5 years; 119 girls, 79 boys). Waist circumference, height, and cardio-metabolic blood markers were collected in a fasted state. Estimated VO2peak scores were also collected. Multilevel generalized mixed effects models were employed to examine the independent effect of WHtR and aerobic fitness classification on a child meeting recommended levels for each cardio-metabolic blood marker. Results: A child having a WHtR < 0.5 related to meeting recommended levels for HDL cholesterol (OR = 3.25, p < .01), triglycerides (OR = 2.94, p < .01), glucose (OR = 3.42, p < .01), and related to a lower continuous Mean Arterial Pressure (MAP) score ((3 = -8.5 mmHg, p < .01). Aerobic fitness classification only independently related to meeting recommended levels for HDL cholesterol (OR = 2.94, p = .010). Conclusion: Having a WHtR < 0.5 independently associated with favorable cardio-metabolic blood markers and thus serves as an effective screening tool for cardio-metabolic risk in Hispanic children from low-income schools. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest 5-year survival rates of any cancer in the United States. Our previous work has shown that autophagy can promote PDAC progression. We recently established the importance of autophagy in regulating bioavailable iron to control mitochondrial metabolism in PDAC. We found that inhibition of autophagy in PDAC leads to mitochondrial dysfunction due to abrogation of succinate dehydrogenase complex iron sulfur subunit B (SDHB) expression. Additionally, we observed that cancer-associated fibroblasts (CAFs) can provide iron to autophagy-inhibited PDAC tumor cells, thereby increasing their resistance to autophagy inhibition. To impede such metabolic compensation, we used a low iron diet together with autophagy inhibition and demonstrated a significant improvement of tumor response in syngeneic PDAC models. Abbreviations: PDAC: Pancreatic ductal adenocarcinoma; CAFs: cancer-associated fibroblasts; SDHB: succinate dehydrogenase complex iron sulfur subunit B; ISCA1: iron sulfur cluster assembly protein 1; FPN: ferroportin; LIP: labile iron pool; FAC: ferric ammonium chloride; OCR: oxygen consumption rate; OXPHOS: oxidative phosphorylation, IL6: interleukin 6; Fe-S: iron sulfur; ATP: adenosine triphosphate. [ABSTRACT FROM AUTHOR]

Determine whether the ACSM walking equations, which calculate caloric expenditure, were accurate for college-aged males and females. Between 2011 and 2016, 100 college-aged males, 20.24 ± 2.0 years old, and 100 college-aged females, 20.8 ± 1.3 years old, volunteered to participate. Participants walked on a treadmill at 80.4 m⋅min−1 at grades of 2, 4, and 6%. Oxygen uptake was measured with an oxygen analyzer (Medgraphics VO2000, Minneapolis, MN). Measurements were converted to caloric expenditure. The mean metabolically derived (MD) VO ̇ 2 values, in ml·kg−1·min−1 for males walking at grades of 2.0, 4.0 and 6.0% were: 15.4 ± 2.7, 17.3 ± 2.6, 19.6 ± 2.8, respectively, and for females were: 15.2 ± 1.1, 16.0 ± 2.0, 17.4 ± 4.2, respectively. ACSM prediction equation values for VO ̇ 2 at the described parameters are 14.4, 17.3 and 20.8, respectively. ACSM prediction equations are not a good predictor of overall caloric expenditure, in college-aged males and females. [ABSTRACT FROM AUTHOR]

Tinius, RA, Blankenship, M, Maples, JM, Pitts, BC, Furgal, K, Norris, ES, Hoover, DL, Olenick, A, Lambert, J, and Cade, WT. Validity of the 6-minute walk test and Young Men's Christian Association (YMCA) submaximal cycle test during midpregnancy. J Strength Cond Res 35(11): 3236–3242, 2021—Submaximal exercise testing can be a feasible alternative to maximal testing within special populations to safely predict fitness levels; however, submaximal exercise testing has not been well-validated for use during pregnancy. The purpose of this study was to determine the concurrent validity of the 6-minute walk test (6MWT) and the YMCA submaximal cycle test (YMCAT) to predict V̇ o 2max in physically active women during midpregnancy. Thirty-seven (n = 37) pregnant women (22.1 ± 1.4 weeks' gestation) and 10 (n = 10) nonpregnant women participated in the study. Subjects completed a graded maximal treadmill test at 1 visit to measure maximal oxygen consumption (V̇ o 2max), and then subjects completed the 6MWT and YMCAT in randomized order during a separate visit. The predicted V̇ o 2max from each submaximal test were compared with the measured V̇ o 2max from the treadmill test to assess the validity of these tests during pregnancy. Among pregnant women, predicted V̇ o 2max from the YMCAT was not correlated to the measured V̇ o 2max (r = 0.14, p = 0.42), and the predicted V̇ o 2max from the 6MWT was only moderately correlated (r = 0.40, p = 0.016) to the measured V̇ o 2max. Among nonpregnant women, the predicted V̇ o 2max values from both the YMCAT and the 6MWT had strong correlations with the measured V̇ o 2max values (YMCAT: r = 0.71, p = 0.02; 6MWT: r = 0.80, p = 0.006). Neither test demonstrated concurrent validity among the pregnant sample. The main finding is that the YMCAT is not a valid method to estimate V̇ o 2max during midpregnancy (likely due to physiological changes in heart rate [HR] during pregnancy). The 6MWT has potential to be used clinically for estimating fitness as actual and predicted values did positively correlate, and it is not dependent on HR responses to exercise. However, if a precise measure of fitness is needed, then neither test appears to have strong validity for use during midpregnancy. [ABSTRACT FROM AUTHOR]

In the United States, the 2.4-km run is arguably the most common law enforcement aerobic assessment. Potential limitations are that recruits use an internal pacing strategy, the test requires fewer direction changes, and less-fit recruits run for longer. The 20-m multistage fitness test (20MSFT) is commonly used internationally to assess aerobic fitness in law enforcement recruits and provides an external pacing strategy. This study documented sex differences between the 2.4-km run and 20MSFT in law enforcement recruits, and between-test relationships. Retrospective analysis on 8 academy classes (463 men and 87 women) from 1 agency was conducted. The 20MSFT was completed before academy and the 2.4-km run in the first week. Between-sex comparisons in the 2.4-km run and 20MSFT were conducted with independent-samples t-tests and effect sizes. Estimated V̇o2 max from the tests was compared with paired-samples t-tests. Correlations and linear regression calculated 2.4-km run and 20MSFT relationships. There were significant between-sex differences for the 2.4-km run and 20MSFT (p < 0.01), with moderate (d = 0.9) and small (d = 0.4) effects, respectively. Estimated 2.4-km run V̇o2 max was greater than that from the 20MSFT (p < 0.01). The 2.4-km run had significant relationships with the 20MSFT (r = −0.6), although the regression equations were low (r² = 0.30–0.37). Between-sex differences in the 20MSFT seemed less than for those in the 2.4-km run. Nonetheless, even with significant relationships between the tests, the 20MSFT induces a higher running intensity and direction changes. This may limit transferability with the 2.4-km run in law enforcement recruits. [ABSTRACT FROM AUTHOR]

Objective: The primary goal of our retrospective case-control study was to evaluate the ability of cardiopulmonary exercise testing to screen for underlying exercise-induced pulmonary hypertension (EIPH) in symptomatic patients who had a negative stress test and elevated right ventricular systolic pressure on echocardiogram. We also evaluated long-acting nitrates and ranolazine as medication challenges. Setting: Performed at a single, tertiary-care medical center in the United States. Participants: Based on the inclusion and exclusion criteria, 81 patients were included in this study. The primary outcome of the study was to measure mean pulmonary arterial pressure at rest and exertion, as well as Wasserman curves. We also recorded patient demographics and risk factors, left ventricular ejection fraction, and mean oxygen consumption. Additionally, patients were monitored symptomatically after receiving long-acting nitrates and ranolazine. Results: A total of 61 patients had resting pulmonary arterial hypertension, and 27 had EIPH. The EIPH group had a significantly higher mean age of 71.67 years. Wasserman curves calculated from the cardiopulmonary exercise testing data revealed 3 subgroups of EIPH patients: cardiac restriction, chronotropic incompetence, and combination of both patterns. The EIPH group showed significant improvement in symptoms after receiving long-acting nitrate therapy. Conclusions: Many patients with symptoms of angina, dyspnea, and/or fatigue on exertion with negative cardiac stress testing may have underlying pulmonary arterial hypertension, including EIPH. Therefore, these patients require adequate treatment and follow-up to prevent worsening of symptoms and pathology. [ABSTRACT FROM AUTHOR]

Objective: Cardiorespiratory fitness (CRF) is defined as the capacity of the cardiovascular and pulmonary systems to meet the oxygen demands of the body during physical work. Poor CRF is connected with a higher risk for the development of various noninfectious diseases such as cardiovascular disease or malignancies. The standard test for the assessment of CRF is exercise testing with the measurement of maximal oxygen consumption (VO2 max). Standard VO2 max values for adult men and women in the Czech Republic have been available since the 1970s without being updated. According to experts, these standard values are now unusable for contemporary CRF measurements of the population in the Czech Republic. The Fitness Registry and the Importance of Exercise: a National Database (FRIEND) - 4,494 patients (1,717 men) defined new standard values for bicycle ergometry CRF for the population in the United States of America. The aim of the study was the statistical comparison of VO2 max values (reference standards) in the 1970s population in the Czech Republic with the new reference standards of the FRIEND registry.Methods: All analyses were performed using IBM SPSS statistics and all tests with a p-value of less than 0.05 were considered statistically significant.Results: VO2 max norms for women in the Czech population were higher in all age categories with statistically significant differences in the categories 30-39, 40-49 and 50-59 (p < 0.001). In the male population aged 20-29 years, VO2 max was significantly higher in the FRIEND registry (p < 0.001) in contrast to the other age categories, 30-39, 40-49 and 50-59, which were significantly higher in the Czech population (p < 0.001).Conclusions: Czech VO2 max population norms from the 1970s are (with the exception of age category 20-29 years) higher than values from the recent FRIEND registry. [ABSTRACT FROM AUTHOR]

Background: Established reference standards for the ventilatory threshold (Vt) are lacking. The aim of this study was to develop reference standards for the Vt derived from cardiopulmonary exercise testing (CPX) using treadmill and cycle ergometry.Methods: Seven laboratories experienced in CPX administration with established quality control procedures contributed to the Fitness Registry and the Importance of Exercise: A National Database (FRIEND) from April 2014 through February 2019. Vt data from 27 states in the United States and the Ontario Province in Canada, comprising 9,350 tests (treadmill: n = 1,195; cycle ergometer: n = 8,155) in men (n = 7,540) and women (n = 1,810) 20 to 79 years of age who were free from smoking and known cardiovascular, pulmonary, metabolic, and/or neoplastic disease were used to develop the reference standards. Comparisons of Vt values were made between exercise testing modes, sex, and age groups.Results: Vt values on the treadmill were higher than cycle ergometry; men had higher Vt values than women on both test modalities, and the highest Vt values achieved were in the 20- to 29-year-old age group compared with all other age groups (all P < .001). The rates of decline in Vt values from age groups 20 to 29 through 70 to 79 years of age were 23% and 35% in men and 47% and 30% in women for treadmill and cycle ergometry tests, respectively.Conclusions: In addition to previous reference standards from FRIEND for cardiorespiratory fitness, the Vt reference standards reported herein provide valuable information on functional metric. These data have important implications for CPX interpretation and aerobic exercise prescription in the clinical and fitness settings. [ABSTRACT FROM AUTHOR]

Background: Nonexercise models were developed to predict maximal oxygen consumption (VO2max). While these models are accurate, they don't consider smoking, which negatively impacts measured VO2max. The purpose of this study was to examine the effects of smoking on both measured and predicted VO2max. Methods: Indirect calorimetry was used to measure VO2max in 2,749 men and women. Physical activity using the NASA Physical Activity Status Scale (PASS), body mass index (BMI), and smoking (pack-y = packs·day * y of smoking) also were assessed. Pack-y groupings were Never (0 pack-y), Light (1-10), Moderate (11-20), and Heavy (>20). Multiple regression analysis was used to examine the effect of smoking on VO2max predicted by PASS, age, BMI, and gender. Results: Measured VO2max was significantly lower in the heavy smoking group compared with the other pack-y groups. The combined effects of PASS, age, BMI, and gender on measured VO2max were significant. With smoking in the model, the estimated effects on measured VO2max from Light, Moderate, and Heavy smoking were -0.83, -0.85, and -2.56 ml·kg-1min-1, respectively (P < .05). Conclusions: Given that 21% of American adults smoke and 12% of them are heavy smokers, it is recommended that smoking be considered when using nonexercise models to predict VO2max. [ABSTRACT FROM AUTHOR]

Background Exercise is emerging as an important aspect in the management of disease-related symptoms and functional decline in people with Huntington disease (HD). Long-term evaluation of physical activity and exercise participation in HD has yet to be undertaken. Objective The objective is to investigate the feasibility of a nested randomized controlled trial (RCT) alongside a longitudinal observational study of physical activity and exercise outcomes in people with HD. Design This will be a 12-month longitudinal observational study (n = 120) with a nested evaluation of a physical activity intervention (n = 30) compared with usual activity (n = 30) using a "trial within a cohort" design. Setting The study will take place in HD specialist clinics in Germany, Spain, and the United States, with intervention delivery in community settings. Participants The participants will have early-mid–stage HD and be participating in the Enroll-HD study. Intervention This will be a 12-month physical activity behavioral change intervention, delivered by physical therapists in 18 sessions, targeting uptake of aerobic exercise and increased physical activity. Measurements All participants (n = 120) will complete Enroll-HD assessments (motor, cognitive, behavioral, and quality of life) at baseline and at 12 months. Additional Physical ACtivity and Exercise Outcomes in Huntington Disease (PACE-HD) assessments include fitness (predicted maximal oxygen uptake [V   o 2max]), self-reported and quantitative measures of physical activity, disease-specific symptoms, and walking endurance. RCT participants (n = 60) will complete an additional battery of quantitative motor assessments and a 6-month interim assessment. Enroll-HD data will be linked to PACE-HD physical activity and fitness data. Limitations The limitations include that the embedded RCT is open, and assessors at RCT sites are not blinded to participant allocation. Conclusion PACE-HD will enable determination of the feasibility of long-term physical activity interventions in people with HD. The novel "trial within a cohort" design and incorporation of data linkage have potential to reduce participant burden. This design could be applied to other neurological diseases and movement disorders where recruitment and retention are challenging. [ABSTRACT FROM AUTHOR]

To assess energy expenditure (EE) estimated by a metabolic system during the exergame Hollywood Workout on Xbox 360Kinect® and to compare this measure with the EE estimated by the exergame (EEEx). thirty-four physically active young males performed the Sports Athlete protocol of the Hollywood Workout. Oxygen uptake (V̇O2) and carbon dioxide production (V̇CO2) were measured before and during the protocol using a metabolic system. The absolute means V̇O2 and V̇CO2 were used to calculate the EE during the exergame session (EEMS). The EEEx (kcal) provided by the exergame was collected, and the two measures were compared. Mean V̇CO2 and V̇O2 during the Sports Athlete protocol were 1.8±0.4 L·min−1 (22.9±3.2 mL·kg−1.min−1) and 2.0±0.4 L·m−1 (25.4±2.6 mL·kg−1 ·min−1), respectively. The EEMS (300.3±53.4 kcal) was 88.6±34.7% greater than the EEEx (160.3±16.5 kcal; p<0.0001; d=3.7 [large effect size]). The EEMS was almost double EEEx. Thus, it is necessary to use caution when using EE information provided by an exergame interface. Further, future studies need to evaluate EE provided by other exergames. The companies that produce the games must be more attentive and adopt more precise methods in order to provide more accurate information to the users. [ABSTRACT FROM AUTHOR]

Importance: Heart failure with preserved ejection fraction (HFpEF) lacks effective treatments. Based on preclinical studies, neladenoson bialanate, a first-in-class partial adenosine A1 receptor agonist, has the potential to improve several heart failure-related cardiac and noncardiac abnormalities but has not been evaluated to treat HFpEF.Objectives: To determine whether neladenoson improves exercise capacity, physical activity, cardiac biomarkers, and quality of life in patients with HFpEF and to find the optimal dose.Design, Setting, and Participants: Phase 2b randomized clinical trial conducted at 76 centers in the United States, Europe, and Japan. Patients (N = 305) with New York Heart Association class II or III HFpEF with elevated natriuretic peptide levels were enrolled between May 10, 2017, and December 7, 2017 (date of final follow-up: June 20, 2018).Interventions: Participants were randomized (1:2:2:2:2:3) to neladenoson (n = 27 [5 mg], n = 50 [10 mg], n = 51 [20 mg], n = 50 [30 mg], and n = 51 [40 mg]) or matching placebo (n = 76) for 20 weeks of treatment.Main Outcomes and Measures: The primary end point was change in 6-minute walk test distance from baseline to 20 weeks (minimal clinically important difference, 40 m). Key safety measures included bradyarrhythmias and adverse events. To evaluate the effects of varying doses of neladenoson, a multiple comparison procedure with 5 modeling techniques (linear, Emax, 2 variations of sigmoidal Emax, and quadratic) was used to evaluate diverse dose-response profiles.Results: Among 305 patients who were randomized (mean age, 74 years; 160 [53%] women; mean 6-minute walk test distance, 321.5 m), 261 (86%) completed the trial and were included in the primary analysis. After 20 weeks of treatment, the mean absolute changes from baseline in 6-minute walk test distance were 0.2 m (95% CI, -12.1 to 12.4 m) for the placebo group; 19.4 m (95% CI, -10.8 to 49.7 m) for the 5 mg of neladenoson group; 29.4 m (95% CI, 3.0 to 55.8 m) for 10 mg of neladenoson group; 13.8 m (95% CI, -2.3 to 29.8 m) for 20 mg of neladenoson group; 16.3 m (95% CI, -1.1 to 33.6 m) for 30 mg of neladenoson group; and 13.0 m (95% CI, -5.9 to 31.9 m) for 40 mg of neladenoson group. Because none of the neladenoson groups achieved the clinically relevant 40-m increase in 6-minute walk test distance from baseline, an optimal dose of neladenoson was not identified. There was no significant dose-response relationship for the change in 6-minute walk test distance among the 5 different dose-response models (P = .05 for Emax; P = .18 for quadratic; P = .21 for sigmoidal Emax 1; P = .39 for linear; and P = .52 for sigmoidal Emax 2). Serious adverse events were similar among the neladenoson groups (61/229 [26.6%]) and the placebo group (21/76 [27.6%]).Conclusions and Relevance: Among patients with HFpEF, there was no significant dose-response relationship detected for neladenoson with regard to the change in exercise capacity from baseline to 20 weeks. In light of these findings, novel approaches will be needed if further development of neladenoson for the treatment of patients with HFpEF is pursued.Trial Registration: ClinicalTrials.gov Identifier: NCT03098979. [ABSTRACT FROM AUTHOR]

Abstract: Background and Purpose: This study aimed to investigate the metabolic cost during aquatic walking at various depths in people post stroke. The secondary purpose was to examine the differences in metabolic cost between aquatic walking and land walking among individuals post stroke. Design: A cross‐sectional research design is used. Methods: Twelve participants post stroke (aged 55.5 ± 13.3 years) completed 6 min of walking in 4 different conditions: chest‐depth, waist‐depth, and thigh‐depth water, and land. Data were collected on 4 separate visits with at least 48 hr in between. On the first visit, all participants were asked to walk in chest‐depth water at their fastest speed. The walking speed was used as a reference speed, which was applied to the remaining 3 walking conditions. The order of remaining walking conditions was randomized. Energy expenditure (EE), oxygen consumption (VO2), and minute ventilation (VE) were measured with a telemetric metabolic system. Results: Our findings showed statistically significant differences in EE, VO2, and VE among the 4 different walking conditions: chest‐depth, waist‐depth, and thigh‐depth water, and land (all p < .05). The participants demonstrated reduction in all variables as the water depth increased from thigh depth to chest depth. Significantly higher values in EE and VO2 were found when the water depth increased from waist depth to chest depth. However, no significant difference was found in all variables between thigh‐depth and waist‐depth walking. Only thigh‐depth walking revealed significant differences when compared with land walking in all variables. Conclusions: People post stroke consume less energy in chest‐depth water, which may allow them to perform prolonged duration of training. Thigh‐depth water demonstrated greater EE compared with other water depths; thus, it can be recommended for time‐efficient cardiovascular exercise. Waist‐depth water showed similar EE to land walking, which may have been contributed by the countervailing effects of buoyancy and water resistance. [ABSTRACT FROM AUTHOR]

Firefighters’ self-contained breathing apparatus (SCBA) protects the respiratory system during firefighting but increases the physiological burden. Extended duration SCBA (>30 min) have increased air supply, potentially increasing the duration of firefighting work cycles. To examine the effects of SCBA configuration and work cycle (length and rest), 30 firefighters completed seven trials using different SCBA and one or two bouts of simulated firefighting following work cycles common in the United States. Heart rate, core temperature, oxygen consumption, work output and self-reported perceptions were recorded during all activities. Varying SCBA resulted in few differences in these parameters. However, during a second bout, work output significantly declined while heart rates and core temperatures were elevated relative to a single bout. Thirty seven per cent of the subjects were unable to complete the second bout in at least one of the two-bout conditions. These firefighters had lower fitness and higher body mass than those who completed all assigned tasks. Practitioner Summary: The effects of extended duration SCBA and work/rest cycles on physiological parameters and work output have not been examined. Cylinder size had minimal effects, but extended work cycles with no rest resulted in increased physiological strain and decreased work output. This effect was more pronounced in firefighters with lower fitness. [ABSTRACT FROM PUBLISHER]

Background: Obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) are common conditions; the co-occurrence of these diseases, called the overlap syndrome (OVS), has been associated with poor health outcomes.Purpose: The purpose of this Official American Thoracic Society Research Statement is to describe pathophysiology, epidemiology, outcomes, diagnostic metrics, and treatment of OVS, as well as to identify important gaps in knowledge and make recommendations for future research.Methods: Clinicians and researchers with expertise in sleep medicine, pulmonary medicine, or both were invited to participate. Topics were divided among the participants according to their interest and expertise. A literature search was conducted; the search was not a formal systematic review. Evidence was considered and supplemented with the panelists' nonsystematic clinical observations. Important knowledge gaps were identified.Results: Recommendations for research to fill existing knowledge gaps were made. The recommendations were formulated by discussion and consensus.Conclusions: Many important questions about OVS exist. This American Thoracic Society Research Statement highlights the types of research that leading clinicians and researchers believe will have the greatest impact on better understanding the spectrum of disease, improving diagnosis, and optimizing therapy. [ABSTRACT FROM AUTHOR]

Individuals with visual impairments tend to spend less time participating in physical activity and more time engaging in sedentary behaviors than their typically developing peers. The purpose of this study was to examine social cognitive theory-based predictors of physical activity and sedentary behavior for adults with visual impairments. Ninety-two participants, recruited from two visual impairment-related organizations in the United States (Women = 50; Men = 42; ages 18-77 [ Mage = 46.88, SD = 13.91]), completed three questionnaires. Two-way ANOVAs examined differences across sex and vision; hierarchical multiple regression analyses evaluated factors predicting total metabolic equivalent minutes and sitting time. Hierarchical multiple regression analyses revealed that social support significantly predicted total metabolic equivalent minutes while self-regulation predicted sitting time. Age was not predictive of either dependent variable; vision predicted total metabolic equivalent minutes but not sitting time; sex was a significant factor for sitting not total metabolic equivalent minutes. Visual impairment predicted metabolic equivalent minutes but not sitting time. This study provides the first empirical evidence explaining social cognitive theory constructs as predictors of physical activity and sedentary behavior among adults with visual impairments. These results provide a basis for researchers and practitioners to utilize when conceptualizing, implementing, and evaluating future physical activity interventions focusing on this population. [ABSTRACT FROM AUTHOR]

Context: Seventy-seven percent of musculoskeletal injuries sustained by United States Army Special Forces Operators are preventable. Identification of predictive characteristics will promote the development of screening methods to augment injury-prevention programs. Objective: To determine physical and performance characteristics that predict musculoskeletal injuries. Setting: Clinical laboratory. Patients or Other Participants: A total of 95 Operators (age = 32.7 ± 5.1 years, height = 179.8 ±6.9 cm, mass = 89.9 ± 12.7 kg). Main Outcome Measure(s): Laboratory testing consisted of body composition, aerobic and anaerobic capacity, upper and lower body strength and flexibility, balance, and biomechanical evaluation. Injury data were captured for 12 months after laboratory testing. Injury frequencies, cross-tabulations, and relative risks (RRs) were calculated to evaluate the relationships between physical characteristics and injury proportions. Between- groups differences (injured versus uninjured) were assessed using appropriate t tests or Mann-Whitney U tests. Results: Less shoulder-retraction strength (RR = 1.741 [95% confidence interval = 1.003, 3.021]), knee-extension strength (RR = 2.029 [95% confidence interval = 1.011, 4.075]), and a smaller trunk extension : flexion ratio (RR = 0.533 [95% confidence interval =0.341, 0.831]) were significant risk factors for injury. Group comparisons showed less trunk strength (extension: P=.03±, flexion: P=.048) and smaller right vertical ground reaction forces during landing (P = .025) in injured Operators. Knee strength, aerobic capacity, and body mass index were less in the subgroup of spine-injured versus uninjured Operators (P values = .013-.03±). Conclusions: Knee-extension and shoulder-retraction strength were risk factors for musculoskeletal injury in Operators. Less trunk-flexion and -extension strength, higher body mass index, lower aerobic capacity, and increased ground reaction forces during landing were characteristics that may also contribute to musculoskeletal injury. Having 2 or more risk factors resulted in a greater injury proportion (χ2 = 13.512, P = .015); however, more research is needed. Athletic trainers working in the military or similar high-demand settings can use these data to augment screening and injury-prevention protocols. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND We examined the impact of the Fuel Up to Play 60 ( FUTP60) program on children's body mass index ( BMI) and aerobic capacity ( AC). METHODS Participation in the FUTP60 and both BMI and AC profiles were collected through the NFL PLAY 60 FitnessGram Partnership Project involving over 100 schools from 22 US states. We specifically examined the distributions of BMI and AC among participating versus nonparticipating schools in the 2012-2013 school year. Hierarchical linear models tested the impact of participation and availability of additional funding for program implementation on the proportions of youth meeting FitnessGram health-related fitness standards (ie, Needs Improvement-Health Risk [ NIHR] and Healthy Fitness Zone [ HFZ] categories). RESULTS After 1 year implementing the program, participating schools had lower proportions of boys (−4.1 ± 2.0%, p = .04) and girls (−4.5 ± 2.0%, p = .03) in the NIHR for BMI, and lower proportion of girls (−9.7 ± 4.0%, p = .02) in the NIHR for AC. There were no differences in the distributions for the HFZ and the availability of additional funding did not alter the relationships (p > .05). CONCLUSIONS This study provides preliminary evidence that participation in the FUTP60 is associated with improved profiles of health-related fitness. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the effects of an aldosterone antagonist on exercise intolerance in older adults with heart failure and preserved ejection fraction ( HFp EF). Design Randomized, placebo-controlled, double-blind trial. Setting Academic medical center, Winston-Salem, North Carolina. Participants Older adults (N = 80, aged 71 ± 1; 80% female) with stable compensated HFp EF and controlled blood pressure ( BP). Measurements Participants were randomized into a 9-month treatment of spironolactone 25 mg/d vs placebo. Assessments were peak exercise oxygen consumption ( VO2), 6-minute walk test, Minnesota Living with Heart Failure Questionnaire ( MLHFQ), cardiac magnetic resonance imaging, Doppler echocardiography, and vascular ultrasound. Results Seventy-one participants completed the trial: 37 in the spironolactone group and 34 in the placebo group. Adherence according to pill count was excellent (spironolactone 95%, placebo 97%). Mean spironolactone dose was 24.3 ± 2.9 mg/d and was well tolerated. Spironolactone significantly reduced systolic and diastolic BP at rest and peak exercise. At 9-month follow-up, baseline-adjusted peak VO2, the primary outcome, was 13.5 ± 0.3 mL/kg per minute in the spironolactone group versus 13.9 ± 0.3 mL/kg per minute in the placebo group (adjusted mean difference −0.4 mL/kg per minute; 95% confidence interval = −1.1-0.4 mL/kg per minute; P = .38). The 95% confidence intervals of spironolactone's effect on peak VO2 (−8.2% to 3.2%) excluded a clinically significant beneficial effect. There were also no significant differences in 6-minute walk distance, arterial stiffness, left ventricular ( LV) mass, LV mass/end-diastolic volume, or MLHFQ score. Conclusion In older adults with stable compensated HFp EF, 9 months of spironolactone 25 mg/d was well tolerated and reduced BP but did not improve exercise capacity, quality of life, LV mass, or arterial stiffness. [ABSTRACT FROM AUTHOR]

A systematic literature search was conducted to identify and analyze articles that reported on physical fitness of new US Army recruits. The National Library of Medicine's PubMed and the Defense Technical Information Center were searched using the keywords (military personnel OR trainee OR recruit OR soldier) AND (physical fitness OR strength OR endurance OR flexibility OR balance OR coordination OR muscle contraction OR running OR exercise OR physical conditioning). Reference lists of obtained articles and contact with authors enhanced the search. Studies were selected if they involved recruits in Basic Combat Training or One- Station Unit Training, provided a quantitative assessment of at least one fitness measure, and the fitness measure(s) were obtained early in training. Average values for each fitness mea- sure were obtained, plotted by the year of data collection, and fitted to linear regression models (fitness measure 3 year). Fifty-three articles met the review criteria. Regression analysis indicated little temporal change in height, but body weight, body mass index, body fat, and fat-free mass increased over time. Limited ...O2max data suggested no temporal change in male recruits, but those in female recruits ...O2max seem to have slightly improved. Apparently contradicting the ...O2max findings, performance on endurance runs (1- and 2-mile) declined, possibly because of the increase in body weight. Muscular endurance (push-ups, sit-ups) demonstrated little systematic change over time. Limited but multiple measures of muscular strength suggest a temporal increase in strength. Specific components of US Army recruit fitness seem to have changed over time. [ABSTRACT FROM AUTHOR]

A major concern for responders to hazardous materials (HazMat) incidents is the heat strain that is caused by fully encapsulated impermeable (NFPA 1991) suits. In a research project, funded by the US Department of Defense, the thermal strain experienced when wearing these suits was studied. Forty human subjects between the ages of 25 and 50 participated in a protocol approved by the local ethical committee. Six different fully encapsulated impermeable HazMat suits were evaluated in three climates: moderate (24°C, 50% RH, 20°CWBGT), warm-wet (32°C, 60% RH, 30°CWBGT), and hot-dry (45°C, 20% RH, 37°C WBGT, 200 W m-2 radiant load) and at three walking speeds: 2.5, 4, and 5.5 km h-1. The medium speed, 4 km h-1, was tested in all three climates and the other two walking speeds were only tested in the moderate climate. Prior to the test a submaximal exercise test in normal clothing was performed to determine a relationship between heart rate and oxygen consumption (pretest). In total, 163 exposures were measured. Tolerance time ranged from as low as 20 min in the hot-dry condition to 60 min (the maximum) in the moderate climate, especially common at the lowest walking speed. Between the six difference suits limited differences were found, a two-layered aluminized suit exhibited significant shorter tolerance times in the moderate climate, but no other major significant differences were found for the other climates or workloads. An important characteristic of the overall dataset is the large variability between the subjects. Although the average responses seem suitable to be predicted, the variability in the warmer strain conditions ranged from 20 min up to 60 min. The work load in these encapsulated impermeable suits was also significantly higher than working in normal clothing and higher than predicted by the Pandolf equation. Heart rate showed a very strong correlation to body core temperature and was in many cases the limiting factor. Setting the heart rate maximum at 80% of predicted individual maximum (age based) would have prevented 95% of the cases with excessive heat strain. Monitoring of heart rate under operational conditions would further allow individually optimize working times and help in preventing exertional heat stroke. [ABSTRACT FROM AUTHOR]

Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited studies in different geographical regions (i.e., southeast) of the United States. Further, there have been a limited number of studies examining body core temperature of American Football players during preseason practice, especially at the high school level. Future field-based research in American Football with various levels of competition in hotter geographical regions of the United States is warranted. [ABSTRACT FROM AUTHOR]

The objective of the current study was to evaluate the effects of aging on myoglobin chemistry of dark-cutting beef. Ten USDA Choice (mean pH = 5.6; normal pH beef) and 10 no-roll dark cutter (mean pH = 6.4) strip loins were obtained from a commercial packing plant within 3 d of harvest. Loins were cut into 4 sections, vacuum packaged, randomly assigned to 0-, 21-, 42-, and 62-d aging at 2°C in the dark. Following aging, loin sections were cut into 2.5-cm-thick steaks and were used to determine bloom development, oxygen consumption (OC), metmyoglobin reducing activity (MRA), and lipid oxidation. Surface color readings were measured using a HunterLab Miniscan XE Plus spectrophotometer. A significant muscle type × aging time interaction resulted for OC (P < 0.001). Normal pH steaks declined more (P < 0.001) in OC during aging than dark-cutting beef. On d 0, dark-cutting beef had a greater OC (P < 0.001) than normal pH beef. There was a significant muscle type × oxygenation time × aging period interaction for L* values, deoxymyoglobin (DeoxyMb), and oxymyoglobin (OxyMb). When dark-cutting sections were aged for 62 d, both 0 and 60 min bloom development L* values were greater (P < 0.0001) than 0 min dark-cutting sections aged for 21 or 42 d. At all aging periods, normal pH beef had greater OxyMb content and lower DeoxyMb (P < 0.0001) during bloom development than dark-cutting beef. An aging period × muscle type interaction was significant for % overall reflectance (P = 0.0017) and absorbance (P = 0.0038). Dark cutting and normal pH beef loin sections aged for 62 d had greater reflectance (P < 0.0001) than 21 d. On d 0, dark-cutting beef had greater (P < 0.0001) MRA than normal pH beef. There were no significant (P = 0.14) differences in MRA between 42 and 62 d between dark-cutting and normal pH beef. Dark cutting steaks had lower thiobarbituric acid reactive substances values (P < 0.0001) than normal pH steaks. The results indicate that characterizing the myoglobin chemistry during aging will help to design strategies to improve appearance of high pH beef. [ABSTRACT FROM AUTHOR]

Background: Data from a cardiopulmonary exercise (CPX) test are used to determine prognosis in patients with chronic heart failure (HF). However, few published studies have simultaneously compared the relative prognostic strength of multiple CPX variables. Objectives: The study sought to describe the strength of the association among variables measured during a CPX test and all-cause mortality in patients with HF with reduced ejection fraction (HFrEF), including the influence of sex and patient effort, as measured by respiratory exchange ratio (RER). Methods: Among patients (n = 2,100, 29% women) enrolled in the HF-ACTION (HF-A Controlled Trial Investigating Outcomes of exercise traiNing) trial, 10 CPX test variables measured at baseline (e.g., peak oxygen uptake [Vo2], exercise duration, percent predicted peak Vo2 [%ppVo2], ventilatory efficiency) were examined. Results: Over a median follow-up of 32 months, there were 357 deaths. All CPX variables, except RER, were related to all-cause mortality (all p < 0.0001). Both %ppVo2 and exercise duration were equally able to predict (Wald chi-square: ∼141) and discriminate (c-index: 0.69) mortality. Peak Vo2 (ml·kg(-1)·min(-1)) was the strongest predictor of mortality among men (Wald chi-square: 129) and exercise duration among women (Wald chi-square: 41). Multivariable analyses showed that %ppVo2, exercise duration, and peak Vo2 (ml·kg(-1)·min(-1)) were similarly able to predict and discriminate mortality. In men, a 10% 1-year mortality rate corresponded to a peak Vo2 of 10.9 ml·kg(-1)·min(-1) versus 5.3 ml·kg(-1)·min(-1) in women. Conclusions: Peak Vo2, exercise duration, and % ppVo2 carried the strongest ability to predict and discriminate the likelihood of death in patients with HFrEF. The prognosis associated with a given peak Vo2 differed by sex. (Exercise Training Program to Improve Clinical Outcomes in Individuals With Congestive Heart Failure; NCT00047437). [ABSTRACT FROM AUTHOR]

Background: Higher cardiorespiratory fitness (CRF) is cross-sectionally associated with more conserved brain volume in older age, but longitudinal studies are rare. This study examined whether higher midlife CRF was prospectively associated with slower atrophy, which in turn was associated with higher late-life CRF.Methods: Brain volume by magnetic resonance imaging was determined annually from 1994 to 2003 in 146 participants (M baseline age = 69.6 years). Peak oxygen uptake on a treadmill yielded estimated midlife CRF in 138 and late-life CRF in 73 participants.Results: Higher midlife CRF was associated with greater middle temporal gyrus, perirhinal cortex, and temporal and parietal white matter, but was not associated with atrophy progression. Slower atrophy in middle frontal and angular gyri was associated with higher late-life CRF, independent of CRF at baseline magnetic resonance imaging.Conclusions: Higher midlife CRF may play a role in preserving middle and medial temporal volumes in late adulthood. Slower atrophy in middle frontal and angular gyri may predict late-life CRF. [ABSTRACT FROM AUTHOR]

African Americans (AA) have increased carotid artery intima-media thickness and decreased vascular function compared with their Caucasian (CA) peers. Aerobic exercise prevents and potentially reverses arterial dysfunction. Purpose: The purpose of this study was to examine the effect of 8 wk of moderate- to high-intensity aerobic training in young healthy sedentary AA and CA men and women. Methods: Sixty-four healthy volunteers (men, 28; women, 36) with mean age 24 yr underwent measures of arterial structure, function, and blood pressure (BP) variables at baseline, after the 4-wk control period, and 8 wk after training. Results: There was a significant increase in VO2peaj; among both groups after exercise training. Brachial systolic BP decreased significantly after the control period in both groups but not after exercise training. Carotid pulse pressure decreased significantly in both groups after exercise training as compared with that in baseline. There was no change in any of the other BP variables. AA had higher intima-media thickness at baseline and after the control period but it significantly decreased after exercise training compared with that of CA. AA had significantly lower baseline forearm blood flow and reactive hyperemia compared with those of CA, but exercise training had no effect on these variables. There was no significant difference in arterial stiffness (central pulse wave velocity) and wave-reflection (augmentation index) between the two groups at any time point. Conclusions: This is the first study to show that 8 wk of aerobic exercise training causes significant improvement in the arterial structure in young, healthy AA, making it comparable with the CA and with minimal effects on BP variables. [ABSTRACT FROM AUTHOR]

Protective mouthpieces have been used in a variety of sports to decrease the risk of orofacial injury. There are limited data to suggest that mouthpiece use during exercise may also provide an ergogenic effect. The aim of the present study was to investigate the effects of 3 different mouthpiece designs--boil-and-bite (BB) mouthpiece, ethylene vinyl acetate (EVA) custom mandibular mouthpiece, and polypropylene (Poly) custom mandibular mouthpiece--on respiratory physiology parameters and compare them with results of a no-mouthpiece (NM) condition. Sixteen college-aged, recreationally fit subjects ran for 10 minutes in 4 separate trials; mouthpiece conditions were randomly assigned to each trial for all subjects. Respiratory and cardiorespiratory measures, including oxygen uptake, carbon dioxide exhalation, ventilation, heart rate, tidal volume, and respiratory rate (RR), were assessed throughout testing. A repeated-measures analysis of variance indicated that RR was significantly lower (P = 0.04) in the BB mouthpiece condition (27.92 breaths per minute [BPM]) than in the NM condition (30.63 BPM). In paired ttests between conditions, the RR demonstrated in the BB condition (27.92 BPM) was significantly lower (P= 0.04) than that of each other condition (NM, 30.63 BPM; EVA, 29.92 BPM; and Poly, 29.92 BPM). The outcomes of the present study demonstrate that the use of the BB mouthpiece decreased RR during exercise. The differences cited between conditions may be attributed to the design of the mouthpiece and its mandibular placement as well as the activity of the genioglossus muscle. However, future studies should assess these parameters to determine the plausibility of these theories. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) continues to be the leading cause of mortality among all age demographics in the United States, with the highest occurrence in populations aged 65 and older. Glucose levels, particularly hyperglycemia, are associated with the premature onset of age-related diseases including CVD. A major challenge in the treatment of elderly patients with chronically elevated blood glucose is the frequency of hypoglycemic episodes. Molecular mechanisms of hypoglycemia remain unclear, but are associated with premature onset of age-related-diseases. Here we report a mitochondrial metabolic profile assessing short-term (up to six hours) and longer-term (12–24 h) durations of low-glucose stress. We observed that the anti-diabetic biguanide and mitochondrial complex I inhibitor, metformin, can lower and restore the elevated oxygen consumption rate during shorter-term glucose stress to levels similar to that of cells cultured in normal glucose. This effect appears, in part, to involve activation of the 5′ AMP-activated protein kinase (AMPK). [ABSTRACT FROM AUTHOR]

The article presents the Functional Movement Screen (FMS) of fundamental movement patterns that involves athletes movements and sport performances. Primary goal of the FMS which comprises of 7 different movements that are scored on a scale of 0-3 and two of these were specific pain clearance tests is to evaluate the efficiency of exercise training programs and to identify injury risk. The result of FMS conducted on 101 players before all fitness assessments is also presented.

Determine the congruent validity and intra- and inter-day reliability of RMR measures assessed by the ParvoMedics Trueone 2400 hood dilution method (Parvo) and Cosmed K4b² (Cosmed) breath-by-breath metabolic systems. Participants underwent 6 RMR assessments over 2 consecutive mornings, 3 with the Parvo (Day 1: Parvo 1; Day 2: Parvo 2,3), 3 with the Cosmed (Day 1: Cosmed 1; Day 2: Cosmed 2, 3). Measured VE, FEO2, FECO2, VO2, VCO2, kcal/day, and HR values were averaged over a minimum of 10 min. Intra- and inter-day reliability within each system was determined with RMANOVA, and congruent validity was assessed via paired sample t-tests. 31 participants (13 females, 18 males; 27.3±7years, 24.8±3.1 kg.m²) completed the study. There were no significant differences in any within or between day Parvo values or Cosmed values. When systems were compared, there was a significant difference between VE (Parvo2: 25.03 L/min, Cosmed2: 8.98L/min) and FEO2 (Parvo2: 19.68%, Cosmed2: 16.63%), however, there were no significant difference in device-calculated RMR (kcals/day). The Parvo and Cosmed are reliable metabolic system with no intra- or inter-day differences in RMR. Due to differences in measurement technology, FEO2, VE were significantly different between systems, but the resultant RMR values were not significantly different. [ABSTRACT FROM AUTHOR]

Studies on nonelite distance runners suggest that men are more likely than women to slow their pace in a marathon. PURPOSE: This study determined the reliability of the sex difference in pacing across many marathons and after adjusting women's performances by 12% to address men's greater maximal oxygen uptake and also incorporating information on racing experience. METHODS: Data were acquired from 14 US marathons in 2011 and encompassed 91,929 performances. For 2929 runners, we obtained experience data from a race-aggregating Web site. We operationalized pace maintenance as the percentage change in pace observed in the second half of the marathon relative to the first half. Pace maintenance was analyzed as a continuous variable and as two categorical variables, as follows: "maintain the pace," defined as slowing <10%, and "marked slowing," defined as slowing ≥30%. RESULTS: The mean change in pace was 15.6% and 11.7% for men and women, respectively (P < 0.0001). This sex difference was significant for all 14 marathons. The odds for women were 1.46 (95% confidence interval, 1.41-1.50; P < 0.0001) times higher than men to maintain the pace and 0.36 (95% confidence interval, 0.34-0.38; P < 0.0001) times that of men to exhibit marked slowing. Slower finishing times were associated with greater slowing, especially in men (interaction, P < 0.0001). However, the sex difference in pacing occurred across age and finishing time groups. Making the 12% adjustment to women's performances lessened the magnitude of the sex difference in pacing but not its occurrence. Although greater experience was associated with less slowing, controlling for the experience variables did not eliminate the sex difference in pacing. CONCLUSIONS: The sex difference in pacing is robust. It may reflect sex differences in physiology, decision making, or both. [ABSTRACT FROM AUTHOR]

Physiological maintenance of ectotherms is largely dependent on temperature. Abrupt changes in environmental conditions can cause shifts in energy budgets, with higher temperatures requiring more energy be devoted to maintenance functions, making less energy available for other activities. As a group, freshwater turtles are of conservation concern; thus, it is important to understand their physiological responses to temperature shifts, particularly given current climate change predictions. We quantified metabolic rates (MR) for three species of semi-aquatic turtles that vary in their degree of terrestriality and propensity to aestivate: chicken turtles (Deirochelys reticularia), eastern mud turtles (Kinosternon subrubrum), and eastern musk turtles (Sternotherus odoratus). Metabolic trials were performed using a flow-through respirometer at three environmentally-relevant temperatures: 25 °C, 30 °C, and 35 °C. As expected, MRs of turtles were significantly and positively associated with increases in mass and temperature. Pairwise comparisons revealed that D. reticularia exhibited significantly higher oxygen consumption rates (VO 2) relative to K. subrubrum , which had significantly higher VO 2 than S. odoratus. The combination of higher metabolic rates, the tendency to terrestrially aestivate, and declining quantity of high quality thermal habitats may place some semi-aquatic turtles at a disadvantage when considering future climate scenarios. Our findings, when combined with knowledge of other ecological traits, may be a useful tool for predicting relative sensitivities of turtle species to predicted climate change, particularly those species inhabiting seasonal wetlands. • Metabolic rate (MR) was positively associated with mass and temperature increases. • Chicken turtles had higher MRs than both mud and musk turtles at all temperatures. • Projected climate shifts threaten persistence of turtles that rely on aestivation. [ABSTRACT FROM AUTHOR]

Objective: To explore the association between cardiovascular fitness and metabolic syndrome across occupational groups using a nationally representative sample of the US population. Methods: Respondents aged 18 to 49 years from the 1999 to 2004 National Health and Nutrition Examination Survey were evaluated for cardiovascular fitness and classified with regard to metabolic syndrome. Comparisons were made across 40 occupational categories. Results: For all occupations with and without metabolic syndrome, the estimated maximal oxygen consumption (VO2max) was 38.8 mL/kg/min (standard error = 0.5) and 41.1 mL/kg/min (standard error = 0.2), respectively. The estimated VO2max was higher for those without metabolic syndrome for most occupational groups, particularly for sales supervisors and proprietors, sales representatives, finance, business, and commodities, and freight, stock, and material movers. Conclusions: Low estimated VO2max among workers with metabolic syndrome can be addressed, in part, by workplace interventions designed to increase fitness. This study identifies priority occupational groups for these interventions.f [ABSTRACT FROM AUTHOR]

The article reports on research which was conducted to investigate changes in functional movement patterns in collegiate soccer and volleyball players over the course of a competitive season. Researchers evaluated 57 athletes. They found that changes in movement patterns were seen in both volleyball and soccer players over the course of a competitive season.

Current American College of Sports Medicine (ACSM) guidelines recommend replacing 150% of sweat losses between training bouts separated by ≤12 hours, but little evidence exists concerning the implications of this strategy for runners. Participants (n = 13) in this study replaced 75% (1637 ± 372 mL) or 150% (3099 ± 850 mL) of sweat losses following an outdoor evening run (∼75 minutes; Wet-bulb-globe temperature (WBGT) = ∼27°C) and consumed a standardised evening meal and breakfast before completing an outdoor (WBGT = ∼23°C) 10-km time-trial the following morning. Urine was collected between runs and urine specific gravity (USG) was assessed pre-run. Significant differences were found in pre-run body mass (75% = 69.6 ± 9.2; 150% = 70.1 ± 9.3 kg; P = 0.02) and USG (75% = 1.026 ± 0.005; 150% = 1.014 ± 0.007; P < 0.001). Heart rate during 10-km run (168 ± 14 versus 168 ± 12 beats min−1) and post-run intestinal temperature (39.08 ± 0.52 versus 39.00 ± 0.70 °C) did not differ for 75% and 150%, respectively, despite an ∼3% performance improvement (75% = 47.28 ± 6.64; 150% = 45.93 ± 6.04 minutes; P = 0.001) due to a faster pace in the second half of the run with 150% replacement. Session rate of perceived exertion (RPE) was lower (P = 0.02) during 150% (7.5 ± 1.3) versus 75% (8.4 ± 0.9). Reluctant drinkers potentially hinder training quality between evening and morning runs in the heat, but copious urine production and difficulty in consuming recommended fluid volumes suggest fluid replacement <150% may be more ideal. [ABSTRACT FROM AUTHOR]

Introduction: Cardiorespiratory fitness is a predictor of cardiovascular and all-cause mortality. Its assessment in different groups has clinical and public health usefulness. Objective: To evaluate the validity and reproducibility of a no-exercise method [National Aeronautics and Space Administration (NASA) method] to estimate the maximum oxygen consumption (VO2máx) in college adults. Materials and methods: This study included 94 healthy individuals of both sexes (18-55 years). The gold standard was ergospirometry. The validity and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and the Bland-Altman method. Results: Among the participants, we found a mean age of 30.54 ± 9.33 years and a VO2máx of 41.29 ± 9.54 ml O2.kg-1.min-1; 48.9 % were women. A mean difference of VO2máx between ergospirometry and that estimated by the NASA method of 3.41 ± 5.64 ml O2.kg-1.min-1 was found. The concordance between the two methods was good, with an ICC of 0.858 (CI95% 0.672-0.926). The percentage of error was 29.70 %. The reproducibility of the two estimates by the NASA method was excellent, with an ICC of 0.986 (CI95% 0.927-0.995). Conclusions: The NASA method is valid and reproducible to estimate VO2máx in college adults. In addition, it is safe and easy to apply. Estimating cardiorespiratory fitness is recommended to improve screening in cardiometabolic risk programs and to implement timely interventions.

The purpose of this investigation was to compare accelerometer activity counts and oxygen consumption between young and elderly individuals. Sixteen young (21.3 ± 2.5 yrs) and sixteen elderly (66.6 ± 2.9 yrs) participants completed 30 minutes of resting oxygen consumption to determine resting metabolic rate and four 6 min walking intensities ranging from 27 to 94 m·min-1. Resting oxygen uptake was significantly lower for the older participants. Exercise oxygen consumption was significantly higher for the elderly group. There were no significant differences in activity counts between groups at each of the exercise intensities. When using measured resting metabolic rate, activity counts of 824 and 2207 counts-min-1 were associated with moderate (3METs) physical activity intensity for the older and young participants, respectively. However, using standard resting metabolic rate (3·5 mL·kg-1·min-1), activity counts of 784 and 2009 counts·min-1 were associated with moderate physical activity intensity for the elderly and young participants, respectively. These findings indicate that activity counts are similar across age groups even though the oxygen consumption of exercise is greater among elderly individuals. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine whether the published left-wrist cut points for the triaxial Gravity Estimator of Normal Everyday Activity (GENEA) accelerometer are accurate for predicting intensity categories during structured activity bouts. Methods: A convenience sample of 130 adults wore a GENEA accelerometer on their left wrist while performing 14 different lifestyle activities. During each activity, oxygen consumption was continuously measured using the Oxycon mobile. Statistical analysis used Spearman's rank correlations to determine the relationship between measured and estimated intensity classifications. Cross tabulations were constructed to show the under- or overestimation of misclassified intensities. One-way x3 tests were used to determine whether the intensity classification accuracy for each activity differed from 80%. Results: For all activities, the GENEA accelerometer-based physical activity monitor explained 41.1% of the variance in energy expenditure. The intensity classification accuracy was 69.8% for sedentary activities, 44.9% for light activities, 46.2% for moderate activities, and 77.7% for vigorous activities. The GENEA correctly classified intensity for 52.9% of observations when all activities were examined; this increased to 61.5% with stationary cycling removed. Conclusions: A wrist-worn triaxial accelerometer has modest-intensity classification accuracy across a broad range of activities when using the cut points of Esliger et al. Although the sensitivity and the specificity are less than those reported by Esliger et al., they are generally in the same range as those reported for waist-worn, uniaxial accelerometer cut points. [ABSTRACT FROM AUTHOR]

The article reports on the benefits that heart failure patients can obtain from participating in exercise training and discusses recommendations which have been issued on aerobic, resistance an inspiratory muscle training for heart failure patients. Research which has investigated the impact that exercise training has on heart failure patients is discussed. Challenges which are associated with providing exercise training for heart failure patients are examined.

The article discusses research which was conducted to investigate the short term effects quercetin supplementation had on aerobically demanding soldier performance. Researchers evaluated 16 male soldiers who performed three days of aerobically demanding exercise. They found that supplementation with quercetin had no positive effect on aerobically demanding soldier performance.

Resistance training (RT) is now an integral component of a well rounded exercise programme. For a correct training prescription, it is of the utmost importance to understand the interaction among training variables, such as the load, volume, rest interval between sets and exercises, frequency of sessions, Exercise modality, repetition velocity and, finally, exercise order. Sports medicine research has indicated that exercise order is an important variable that affects both acute responses and chronic adaptations to RT programmes. Therefore, the purpose of this review was to analyse and discuss exercise order with relevance to acute responses (e.g. repetition performance) and also the expression of chronic adaptable characteristics (e.g. maximal strength and hypertrophy). To accomplish this purpose, the Scielo, Science Citation Index, National Library of Medicine, MEDLINE, Scopus, SPORTDiscus~M and CINAHL® databases were accessed to locate previously conducted original scientific investigations. The studies reviewed examined both acute responses and chronic adaptations with exercise order as the experimental variable. Generally,, with relevance to acute responses, a key finding was that exercise order affects repetition performance over multiple sets, indicating that the total repetitions, and thus the volume, is greater when an exercise is placed at the beginning of an RT session, regardless of the relative amount of muscle mass involved. The pre-exhaustion method might not be an effective technique to increase the extent of neuromuscular recruitment for larger muscle groups (e.g. pectoralis major for the bench press) when preceded by a single-joint movement (e.g. pec-deck fly). With relevance to localized muscular endurance performance, oxygen consumption and ratings of perceived exertion, the limited amount of research conducted thus far indicates that exercise order does not appear to impact the acute expression of these variables. In terms of chronic adaptations, greater strength increases were evident by untrained subjects for the first exercise of a given sequence, while strength increases were inhibited for the last exercise of a given sequence. Additionally, based on strength and hypertrophy (i.e. muscle thickness and volume) effect-size data, the research suggests that exercises be ordered based on priority of importance as dictated by the training goal of a programme, irrespective of whether the exercise involves a relatively large or small muscle group. In summary, exercise order is an important variable that should receive greater attention in RT prescription. When prescribed appropriately with other key prescriptive variables (i.e. load, volume, rest interval between sets and exercises), the exercise order can influence the efficiency, safety and ultimate effectiveness of an RT programme. [ABSTRACT FROM AUTHOR]