Higher Aerobic Fitness Research Articles

Habitual physical activity is not associated with lower cardiovascular risk profile or higher aerobic fitness

Introduction: Physical inactivity is considered as one of the factors to increase the risk of developing cardiovascular diseases (CVDs) and decrease aerobic fitness mainly in middle-age. Increased habitual physical activity (HPA) is one of the strategies recommended to reduce physical inactivity. However, it is not known whether middle-age individuals who exclusively perform greater amount of HPA have greater aerobic fitness and / or a lower risk of CVDs. Objective: Verify the association between HPA with the risk of CVDs and aerobic fitness in individuals who only perform HPA. Method: We selected 89 male volunteers, age: 47.4 ± 5.06 years, who did not practice systemized physical training. Our measurements were: HPA by the International Physical Activity Questionnaire and Baecke questionnaires, the aerobic fitness by direct assessment of maximal oxygen consumption (VO2 máx) and the risk of developing cardiovascular disease by the score calculation of General Cardiovascular Risk Profile from Framingham Study. Results: There was no correlation of the HPA level with cardiovascular risk factors, general cardiovascular disease risk and VO2 máx. Moreover, no difference was found between the categorical groups of the IPAQ questionnaire and between the groups, “clusters”, calculated from the Baecke questionnaire scores for the variables of cardiovascular risk, general cardiovascular disease risk and VO2 máx. Conclusion: This study have found that the HPA level of middle-aged men is not associated with lower cardiovascular risk profile or higher aerobic fitness, suggesting that only increase HPA may not be enough to promote beneficial adaptations in aerobic fitness and improve risk profile for CVDs. These results may be related to low volume and intensity of HPA, which reinforces the importance of performing physical training with control of these variables for health promotion.

Better Executive Function Is Associated With Faster On-Transition Aerobic Metabolism Among Older Adults.

The present study aimed to examine relationships between executive function (EF) and variables of aerobic fitness. Participants were 32 healthy older adults (M age = 65.1, SD = 6.6 years). We measured the first ventilatory threshold (VeT1) and the kinetics of oxygen uptake (O2), heart rate (HR), and muscle deoxygenation [HHb] during treadmill walking of either constant, moderate intensity, or increasing intensity. We assessed EF with a computerized Stroop test and Stroop measures of correct answers, reaction time, and percent interference. We found the Stroop interference score to be negatively associated with the VeT1 (r = -0.387, p = 0.031) and positively associated with the on-transition aerobic metabolism time constant (τ) of HR (r = 0.519, p = 0.003), O2 (r = 0.454; p = 0.010), and [HHb] (r = 0.644, p = 0.001). Correct responses were negatively related with τHR (r = -0.372, p = 0.039) and τO2 (r = -0.500, p = 0.004). The Stroop average reaction time, congruent reaction time and incongruent reaction time were positively related to τ[HHb] (r = 0.507, p = 0.010; r = 0.437, p = 0.029; r = 0.558, p = 0.004, respectively). Better EF was associated with faster on-transition aerobic metabolism and higher aerobic fitness among older adults.

Insulin Stimulation Reduces Arterial Stiffness In Adults With Metabolic Syndrome

PURPOSE: Adults with metabolic syndrome (MetS) have increased fasting arterial stiffness compared with healthy counterparts, and this, in turn, increases risk for cardiovascular disease (CVD) and cardiac events. Although insulin acts to reduce arterial stiffness in healthy adults, the effects in obese individuals with MetS are unclear. We hypothesized that insulin stimulation would reduce measures of arterial stiffness in relation to aerobic fitness and body fat. METHODS: Thirty-one obese adults (24F; 53.7±6.0yrs; 37.4±4.8kg/m2) were screened for MetS (NCEP ATP III criteria) following an overnight fast. Augmentation index (AIx), augmentation pressure (AP) and brachial systolic (bSBP) and diastolic blood pressure (bDBP) were assessed using SphygmoCor before and after a 2hr euglycemic-hyperinsulinemic clamp (90 mg/dl, 40 mU/m2/min). Aerobic fitness (VO2peak; ml/kg/min) was measured through a treadmill protocol while body fat (BF; %) was determined using DEXA. RESULTS: Compared to fasting, insulin significantly reduced AIx (28.5 ± 9.9 vs. 23.2 ± 9.9%, P<0.01) and AP (15.1 ± 6.7 vs. 21.1 ± 5.8 mmHg, P<0.01). However, there was no effect of insulin on bSBP (P=0.19) or bDBP (P=0.21). Fasting AIx and AP correlated with VO2peak (r=-0.42, P=0.02 and r=-0.37, P=0.04) and BF (r=0.64, P<0.01 and r=0.68, P<0.01). Interestingly, neither the change in AIx nor AP from fasting to insulin stimulation correlated with VO2peak (r=-0.18, P=0.33 and r=-0.12, P=0.95) or BF (r=-0.29, P=0.24 and r=-0.17, P=0.58). CONCLUSION: Insulin stimulation reduces indices of arterial stiffness in adults with MetS. While high aerobic fitness and lower BF may contribute to less arterial stiffness in the fasted state, they were not associated with insulin action. This suggests that insulin impacts arterial stiffness through another mechanism. Future research is warranted to determine the role of insulin on arterial health in order to optimize CVD prevention/treatment. Funding was supported by the National Institutes of Health RO1-HL130296.

Effect of C242T Polymorphism in the Gene Encoding the NAD(P)H Oxidase p22phox Subunit and Aerobic Fitness Levels on Redox State Biomarkers and DNA Damage Responses to Exhaustive Exercise: A Randomized Trial.

NAD(P)H oxidases (NOXs) constitute a principal source of cellular reactive oxygen species (ROS) and contribute to exercise-induced ROS production in the skeletal muscle. Here, we aimed to investigate the effect of single-bout exhaustive exercise on redox state biomarkers and oxidative DNA damage based on the C242T polymorphism in the gene encoding NOXs subunit p22phox (CYBA) and aerobic fitness levels. We enrolled 220 healthy adults in their 20s (men, n = 110; women, n = 110), who were divided into CC genotype and T allele groups through the analysis of the CYBA C242T polymorphism. Furthermore, maximum oxygen uptake (VO2max) was evaluated to divide subjects into high fitness (HF; 70th percentile for aerobic fitness) and mid-range fitness (MF; 40–60th percentile for aerobic fitness) groups, with a total of 32 subjects assigned to four groups (eight subjects per group): CC genotype and HF group (CC + HF), CC genotype and MF group (CC + MF), T allele and HF group (T + HF), and T allele and MF group (T + MF). All subjects performed treadmill running exercise at 85% of VO2max until exhaustion. Plasma lactate, malondialdehyde (MDA), superoxide dismutase (SOD), and lymphocyte DNA damage (tail DNA percentage [TD], tail length [TL], and the tail moment [TM]) were measured in the blood samples obtained immediately before (IBE), immediately after (IAE), and 30 min after exercise (30 MAE). Plasma lactate levels, SOD activities, and lymphocyte DNA damage markers (TD, TL, and TM) were significantly increased at IAE than that at IBE and significantly decreased at 30 MAE (p < 0.05). All groups displayed increased plasma MDA levels at IAE rather than at IBE, with CC + MF being significantly higher than T + HF (p < 0.05); only the CC + HF and T + HF groups exhibited a significant reduction at 30 MAE (p < 0.05). Moreover, TL at IAE was significantly higher in the CC + MF group than in the T + HF group (p < 0.05), and significantly higher in the CC + MF and CC + HF groups than in the T + HF group at 30 MAE (p < 0.05). TM was significantly higher in the T + MF than in the T + HF group at IAE (p < 0.05) and that of CC + MF was significantly higher than CC + HF and T + HF values at IAE and 30 MAE (p < 0.05). These results suggest that single-bout exhaustive exercise could induce peripheral fatigue and the accumulation of temporary redox imbalance and oxidative DNA damage. Moreover, high aerobic fitness levels combined with the T allele may protect against exercise-induced redox imbalance and DNA damage.

Substrate Utilization During High‐Intensity Interval Training as a Novel Index of Metabolic Flexibility

Metabolic flexibility is the ability to appropriately store or utilize substrates and is traditionally assessed during the transition between fasted and feeding. However, exercise is also a robust test of one’s ability to shift between substrates to support metabolic demand. We explored whether an individual’s capacity for substrate shifting during high intensity interval exercise (HIIT) could provide a novel means of assessing metabolic flexibility. The study aim was to determine the relationship between fat oxidation during HIIT and following a single high fat meal (HFM), and the impact of aerobic fitness status and mitochondrial capacity on both HIIT‐ and HFM‐based assessments of metabolic flexibility. Recreationally trained men (n=11) and women (n=7) underwent three sessions. Women were tested during days 1–7 of their menstrual cycle. HIIT sessions were comprised of 4 × 4 min high intensity intervals performed at the power output corresponding to 50% of the difference between the ventilatory threshold and VO2 max. Intervals were separated by 3 min unloaded (0W) active recovery. Respiratory gasses were assessed throughout and for 20 minutes following exercise. Blood glucose, lactate and RPE were collected following each interval and during recovery. HFM sessions included a fasted resting metabolic assessment followed by ingestion of a high fat meal. Blood glucose, resting energy expenditure, fat (FOX) and carbohydrate oxidation (COX) measurements were taken at baseline (T0) and every 30 minutes for four hours during the post prandial period (T1–T8). The high‐fat meal consisted of 0.5 g carbohydrate, 1.3 g fat, and 0.2 g protein per kg FFM. Both testing sessions were conducted after an overnight fast. Participants were split into high aerobic fitness status (HFS; n=9; 23±4 yrs; 22.1±4.7% BF; NIRS 1.8±0.8 sec−1; VO2 max 47.5±4.4 ml/kg/min) or low aerobic fitness status (LFS; n= 10; 22±3 yrs; 25.8±5.0% BF; NIRS 1.16±0.1*sec−1; VO2 max 35.5±3.7*ml/kg/min; *p≤0.05). There was a significant correlation between total g fat oxidized (g/kg) during HIIT and HFM (R2=0.54; p=0.03). Significant correlations were observed between VO2 max vs g fat oxidized (g/kg) during HIIT (R2=0.561; p=0.016) and VO2 max vs total percent of substrate oxidized coming from fat during HIIT (R2=0.585; p=0.011), but not for the HFM. Areas under the FOX and COX (g/kg*total min) curves were greater in HFS than LFS during HIIT (p≤0.05). Differences between groups in Total FOX (g/kg) for HIIT approached significance (p=0.06) with total percent of substrate oxidized during HIIT coming from fat being significantly greater in HFS than LFS (HFS: 11.9±0.04% vs LFS: 6.1±0.02%; p≤0.01). FOX rate (g/kg/min) was significantly increased from baseline to T1 and T6‐T8 across all time points (p&lt;0.05), with no differences between groups at any time point during the HFM. These results indicate a significant relationship between postprandial and exercise metabolic flexibility as indicated by fat oxidation. Despite the observed relationship between HIIT‐ and HFM‐based measures of metabolic flexibility, the HIIT protocol used in the current study may uncover metabolic differences induced by training not captured by the traditional HFM approach.Support or Funding InformationA. Olenick is funded by the Mary Ella Lunday Soule Scholarship.

A comparative study of cardio-metabolic responses to exercise between untrained non-athletic young Nigerian adults and trained soccer players

We aimed at evaluating the cardiovascular and metabolic responses to sub-maximal exercise tests in untrained non-athletic young adults and comparing them with those of trained and more active soccer players. Forty healthy young adult males (20 untrained non-athletic undergraduates and 20 trained soccer players) aged 20-35 years participated in the study. The participants performed the exercise tests using a mechanically braked magnetic ergometer bicycle. Blood pressure and heart rate (HR) of participants were measured at rest and during the exercise test. The steady-state oxygen uptake (VO2SS) of subjects was estimated from a standardised sub-maximal VO2 equation. Data indicated significantly (P&lt;0.05) higher absolute VO2SS, relative VO2SS, work rate, exercise oxygen pulse and cardiac output, but lower steady-state HR and %HRmax among the soccer players compared with the untrained individuals. No significant differences were observed in exercise systolic blood pressure, rate pressure product, resting HR reserve and %HR reserve between the two groups. Pearson’s partial correlation test indicted independent relationships between VO2SS (relative and absolute) and oxygen pulse, steady-state HR, percentage of HRmax, percentage of HR reserve, resting HR and working HR reserve respectively. The present study indicated greater cardio-metabolic responses to sub-maximal exercise and higher aerobic fitness in trained soccer players compared with the untrained non-athletic individuals.

Skin Color Cues to Human Health: Carotenoids, Aerobic Fitness, and Body Fat.

Colorful carotenoid ornaments are sexually selected signals of health in many species. In humans too, carotenoids could provide a perceptible cue to health as they impart an attractive yellow-orange color to skin. Increasing carotenoid pigmentation and skin yellowness is associated with increased fruit and vegetable intake, but whether other aspects of human health benefit skin color is unknown. Carotenoids, as antioxidants, help maintain oxidative balance but are expended in this role. Therefore, any health factor affecting oxidative balance could alter the quantity of carotenoids available to color skin. Exercise increases endogenous antioxidant capacity and consequently may decrease expenditure of carotenoids. Fitness could also raise skin carotenoids by lowering body fat (a source of oxidative stress). Here we investigate the relationship between skin color (measured spectrophotometrically), aerobic fitness (measured by estimating the maximum volume of oxygen that a person can use per unit of time, VO2 max), and body fat. In a cross-sectional design, we find that both higher aerobic fitness and lower body fat are predictors of skin yellowness, independent of each other and dietary fruit and vegetable intake. In a longitudinal design over 8 weeks, we found that increase in fitness and decrease in body fat were independently associated with an increase in skin yellowness. Change in self-reported stress and sleep were further predictors of skin yellowness indicating a more general relation between health and skin tone. Simulations of the skin color associated with higher fitness were found to appear healthier. Hence, our results suggest that increasing cardiovascular fitness and decreasing fat levels produce a healthier skin color. Such findings have repercussions for public health because improved attractiveness can provide an incentive for a healthier lifestyle, including exercise and weight regulation.

Patterns and predictors of exercise behavior during 24\u2009months of follow-up after a supervised exercise program during breast cancer chemotherapy

BackgroundUnderstanding the longer-term exercise behavior of patients with breast cancer after chemotherapy is important to promote sustained exercise. The purpose of the current study was to report the longer-term patterns and predictors of exercise behavior in patients with breast cancer who exercised during chemotherapy.MethodsIn the Combined Aerobic and Resistance Exercise (CARE) Trial, 301 patients with breast cancer were randomized to three different exercise prescriptions during chemotherapy. Exercise behaviors after chemotherapy were self-reported at 6-, 12-, and 24-month follow-up. Exercise patterns were identified by categorizing patients according to which exercise guideline they were meeting (neither, aerobic only, resistance only, or combined) at each of the three follow-up timepoints (64 possible patterns). Predictors of longer-term exercise behavior included physical fitness, patient-reported outcomes, and motivational variables from the theory of planned behavior assessed at postintervention (postchemotherapy). Univariate and multivariate stepwise multinomial logistic regression and linear regression were used for statistical analyses.ResultsA total of 264 (88%) participants completed all three follow-up exercise behavior assessments and exhibited 50 different exercise patterns. Postintervention aerobic fitness was the most consistent predictor of longer-term exercise behavior at all three timepoints. For example, higher aerobic fitness (per 1 ml/kg/min) predicted better adherence to the “aerobic only” (OR = 1.09; p = 0.005) and “combined” (OR = 1.12; p < 0.001) guidelines compared to “neither” guideline at 6-month follow-up. Additionally, higher postintervention muscular strength (per 1 kg) was associated with better adherence to the “resistance only” (OR = 1.07; p = 0.025) and “combined” (OR = 1.08; p < 0.001) guidelines compared to “neither” guideline at 24-month follow-up. Finally, lower perceived difficulty (per 1 scale point) was associated with better adherence to the “combined” (OR = 0.62; p = 0.010) and “aerobic only” (OR = 0.58; p = 0.002) guideline compared to the “neither” guideline at the 24-month follow-up.ConclusionsOur study is the first to show that the longer-term exercise patterns of patients with breast cancer who exercised during chemotherapy are diverse and predicted by physical fitness and motivational variables after chemotherapy. Our novel implications are that improving physical fitness during chemotherapy and applying motivational counseling after chemotherapy may improve longer-term exercise behavior in patients with breast cancer.Trial registration(NCT00249015).

Effects of aerobic fitness on cognitive motor interference during self-paced treadmill walking in older adults.

Older adults experience greater cognitive motor interference (CMI) due to declines in cognitive and physical function. Although aerobic fitness has beneficial effects on cognition, its association with CMI is not clear. This study aims to investigate the effects of aerobic fitness on CMI during self-paced treadmill walking in older adults. Thirty participants (67.6 ± 10.34years, 21 females) were included in a 2-day cross-sectional design study. Aerobic fitness was assessed with the Rockport 1-mile test. The dual-task paradigm consisted of walking only, and dual-task standing and dual-task walking (i.e., standing/walking while performing the Modified Stroop color word test) on a treadmill. To assess CMI, gait speed and accuracy rate were measured to later calculate the dual-task cost for each parameter. Individuals with low aerobic fitness exhibited significantly greater gait speed dual-task cost than individuals with high aerobic fitness (p < 0.05). There were no significant findings for accuracy rate dual-task cost. These study findings are the first to demonstrate increases in CMI in relation to low aerobic fitness. Results can be attributed to the relationship between aerobic fitness and cognition as well as theories related to attentional capacity. Older adults with low aerobic fitness possess greater CMI when compared to older adults with high aerobic fitness. This provides a foundation of knowledge on how aerobic fitness in older adults may affect CMI which can lead researchers to examine the causal relationships between an aerobic exercise intervention program and CMI in older adults.

Aerobic fitness, Mediterranean diet and cardiometabolic risk factors in adults

IntroductionUnhealthy lifestyle and inadequate diet could influence the development of future cardiometabolic disease. The main aim of this study was to determine the association between aerobic fitness and cardiometabolic risk factors in adults, whether this relation is depends of adherence to Mediterranean diet (MD). A secondary aim was to study the combined effect of aerobic capacity and adherence to MD on global cardiometabolic risk score (CMRS). MethodA total of 79 adults (38% women) enrolled between 18–40 year from Cádiz. We measured adiposity indicators, blood pressure, triglycerides, glucose and inflammatory profile (interleukin-6 and tumor necrosis factor) and was computed (CMRS). Aerobic fitness was measured by maximal oxygen comsuption through an incremental stress test by cycleergometer. The MD patterns was measured using the questionnaire of adherence to MD. The association between aerobic fitness and cardiometabolic risk factors was examined using a lineal regression and it was adjusted for different confounders. CMRS on the lifestyle was analyzed using the ANOVA test, with statistical significance level of p<0.05 in Bonferroni. ResultsLinear regression showed inverse association between aerobic fitness and cardiometabolic risk factors (all p≤0.05) in the model without adjustment. Blood pressure and triglycerides lost the association after adjust model for sex, age, and adherence to MD. Participants with high aerobic fitness and high adherence to MD show a lowest CMRS (−1.083±2.325 vs. 2.802±1.759). ConclusionsAerobic fitness was inversely associated with fatness risk factors, that relationship is independent to adherence to MD. A high adherence to MD could modulate blood pressure. A combination of high aerobic capacity and high adherence to MD could reduce the adverse consecuence of a low adherencie to MD.

The association of physical function and quality of life on physical activity for non-small cell lung cancer survivors.

Our study aimed to assess the association between physical function and quality of life (QOL) with physical activity among non-small cell lung cancer (NSCLC) survivors. Participants were 92 NSCLC survivors. Physical activity was assessed by a self-report with physiatrist's interview and the Korean version of the short form of the International Physical Activity Questionnaire (IPAQ-SF). All participants were required to perform three standardized fitness tests. The Korean version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) was used to assess QOL. Factors associated with physical functioning and QOL were determined using multiple linear regression. A significant correlation between metabolic equivalent task minutes per week (MET-min/wk) and aerobic fitness was found (r = 0.277, p = 0.008). Factors associated with aerobic fitness include gender, age, and MET-min/wk. The meeting physical activity guideline group was also a factor associated with aerobic fitness. In the QOL aspect, a significant correlation between MET-min/wk and some QOL score was found. The meeting physical activity guideline group was a factor associated with QOL (global health status, physical function, and role function), not total MET-min/wk. Increased physical activity was associated with higher aerobic fitness and QOL. Engagement in physical activity that met physical activity guidelines was a factor related to aerobic fitness and better QOL in some domains. To improve aspects of aerobic fitness and QOL, we may consider the pattern of physical activity, including regular participation and intensity, rather than total physical activity including basal activity.

Aerobic capacity predict skeletal but not cardiac muscle damage after triathlon \u2013 the Iron(WO)man study

This study examines the association between aerobic capacity and biomarkers of skeletal- and cardiac muscle damage among amateur triathletes after a full distance Ironman. Men and women (N = 55) were recruited from local sport clubs. One month before an Ironman triathlon, they conducted a 20 m shuttle run test to determine aerobic capacity. Blood samples were taken immediately after finishing the triathlon, and analyzed for cardiac Troponin T (cTnT), Myosin heavy chain-a (MHC-a), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), Creatin Kinas (CK), and Myoglobin. Regression models examining the association between the biomarkers and aerobic capacity expressed in both relative terms (mLO2*kg−1*min−1) and absolute terms (LO2*min−1) controlled for weight were fitted. A total of 39 subjects (26% females) had complete data and were included in the analysis. No association between aerobic capacity and cardiac muscle damage was observed. For myoglobin, adding aerobic capacity (mLO2*kg−1*min−1) increased the adjusted r2 from 0.026 to 0.210 (F: 8.927, p = 0.005) and for CK the adjusted r2 increased from -0.015 to 0.267 (F: 13.778, p = 0.001). In the models where aerobic capacity was entered in absolute terms the adjusted r2 increased from 0.07 to 0.227 (F: 10.386, p = 0.003) for myoglobin and for CK from -0.029 to 0.281 (F: 15.215, p < 0.001). A negative association between aerobic capacity and skeletal muscle damage was seen but despite the well-known cardio-protective health effect of high aerobic fitness, no such association could be observed in this study.

Estimation of aerobic fitness levels and its determinants among the school going undernourished Indian children - A field-based study

Background: Higher aerobic fitness in children has many physical and cognitive health benefits and can track into adulthood preventing non-communicable diseases later in life. Data on the levels of aerobic fitness among Indian undernourished children are sparse. Aims and Objectives: The aim of the present study is to perform a field-based study to estimate the levels of aerobic fitness and its determinants among the undernourished Indian children. Materials and Methods: Three hundred clinically healthy children, 50% boys, 7–10.5 years between the body mass index (BMI) Z score of −3 and 0 were recruited. Their anthropometry, lung function, handgrip strength were determined, and their physical activity levels were ascertained. Their aerobic fitness was estimated using 20-m multistage shuttle run test (20-mMSRT) and modified Harvard’s step test (MHST). Results: The estimated aerobic fitness levels were 32.25 ± 4.21 and 37.29 ± 5.96 (ml/kg/min) using 20-mMSRT and MHST, respectively. Body composition (fat-free mass), nutritional level (BMI Z scores), and hemoglobin explained 37% and 44% of the variance in whole-body aerobic fitness (ml/min) using 20-mMSRT and MHST, respectively. Gender difference in the predicted aerobic fitness was not apparent in this undernourished group of children. BMI Z scores were positively correlated with the whole-body aerobic fitness among undernourished Indian children. Conclusion: The estimated levels of aerobic fitness among the Indian undernourished children were found to be low for their age. Improvement in nutrition can positively influence on whole-body aerobic fitness among this group of undernourished children.

Device-Measured Sedentary Behavior, Physical Activity and Aerobic Fitness Are Independent Correlates of Cognitive Performance in Healthy Middle-Aged Adults—Results from the SCAPIS Pilot Study

High aerobic fitness, more moderate to vigorous physical activity (MVPA) and less sedentary behavior (SED) have all been suggested to promote cognitive functions, but it is unclear whether they are independent predictors of specific cognitive domains. This study aimed to investigate to what extent aerobic fitness MVPA and SED are independently associated with cognitive performance among middle-aged Swedish adults. We acquired device-based measures of aerobic fitness, cognitive performance and percent daily time spent in MVPA and SED in Swedish adults (n = 216; 54–66 years old). Aerobic fitness was associated with better performance at one out of two tests of speed/attention and one out of four tests of executive attention, and with worse performance at one of seven tests of memory. Increasing %MVPA was associated with better performance at one out of seven tests of memory and two out of three tests of verbal ability, whereas increasing %SED was associated with better performance at all four tests of executive attention and four out of seven tests of memory. These findings suggest that aerobic fitness, %MVPA and %SED are partly independent correlates of cognitive performance. To fully understand the association between SED and performance at several tests of cognitive function, future investigations might attempt to investigate intellectually engaging SED (such as reading books) separately from mentally undemanding SED (such as watching TV).

Relationship Between Repeated Sprint Ability, Aerobic Capacity, Intermittent Endurance, and Heart Rate Recovery in Youth Soccer Players.

Rodríguez-Fernández, A, Sanchez-Sanchez, J, Ramirez-Campillo, R, Nakamura, FY, Rodríguez-Marroyo, JA, and Villa-Vicente, JG. Relationship between repeated sprint ability, aerobic capacity, intermittent endurance, and heart rate recovery in youth soccer players. J Strength Cond Res 33(12): 3406-3413, 2019-To investigate the relationship between repeated sprint ability (RSA) and several aerobic and anaerobic-related soccer-performance indicators, 45 youth soccer players (age 16.8 ± 0.1 years) were classified into "high" (HAF) or "low" aerobic fitness (LAF) (VO2max ≥ or <60 ml·kg·min, respectively) and completed an RSA test measuring best (RSAbest), mean (RSAmean), total sprint time (RSAtotal), and percent sprint decrement (Sdec). A laboratory VO2max test (LabTest) together with anaerobic threshold (VT) and peak speed was measured (vLabTest). In addition, a 20-m multistage shuttle run test (MSRT) and a soccer-specific test (TIVRE-Soccer test-TST) were completed. Heart rate (HR) and HR recovery (HRR) were measured during all tests. High aerobic fitness presented greater (p ≤ 0.05) performance in LabTest, MSRT and TST, at maximal effort, at VT, as well as faster HRR. RSA was similar between HAF and LAF. Contrary to HAF, LAF showed negative correlation between vLabTest with RSAmean (r = -0.6, p = 0.000) and Sdec (r = -0.4, p = 0.044). Also, LAF showed negative correlation between TST end speed (vTST) and RSAmean (r = -0.5, p = 0.005) and Sdec (r = -0.5, p = 0.003). In LAF, RSA was strongly correlated with locomotor factors (e.g., vTST; VT) in both laboratory and field tests. Athletes with high total HRR (>12.5%) in TST presented better (p ≤ 0.05) Sdec in the RSA test. The multiple regression revealed that the LAF vLabTest explained 44.9, 40.0, and 13.5% of the variance in RSAbest, RSAmean, and Sdec, respectively. Practitioners may consider these findings to optimize youth athletes' assessment and preparation processes.

Associations of Aerobic Fitness and Maximal Muscular Strength With Metabolites in Young Men

High physical fitness is associated with a reduction in risk of cardiovascular diseases and death, but the underlying mechanisms are insufficiently understood. To determine how aerobic fitness and muscular strength are associated with serum metabolome measures. This cross-sectional study included Finnish men receiving military refresher training from May 5, 2015, to November 28, 2015, representing partly overlapping groups of individuals with the lowest vs highest aerobic fitness and the lowest vs highest muscular strength. Data analyses were conducted from January 1, 2018, to May 31, 2019. The associations of aerobic fitness (determined with maximum oxygen consumption in milliliters per minute per kilogram, measured with maximal cycle ergometer test) and muscular strength (determined with a maximal strength test for lower extremities in kilograms) with 66 metabolome measures from fasting serum samples (nuclear magnetic resonance-based metabolomics) were analyzed. Participants included 580 Finnish men (mean [SD] age, 26.1 [6.5] years). Including overlap between groups, there were 196 men in the lowest aerobic fitness group and 197 men in the highest aerobic fitness group as well as 196 men in the lowest muscular strength group and 197 men in the highest muscular strength group. Of 66 studied metabolome measures, 48 differed between high vs low aerobic fitness groups, including small very low-density lipoprotein (standardized median difference, -0.67; 95% CI, -0.83 to -0.49), large high-density lipoprotein (standardized median difference, 0.89; 95% CI, 0.69-1.15), total triglyceride levels (standardized median difference, -0.52; 95% CI, -0.65 to -0.34), isoleucine (standardized median difference, -0.37; 95% CI, -0.55 to -0.16), leucine (standardized median difference, -0.55; 95% CI, -0.72 to -0.34), phenylalanine (standardized median difference, -0.54; 95% CI, -0.71 to -0.32), glycerol (standardized median difference, -0.64; 95% CI, -0.81 to -0.48), and glycoprotein (standardized median difference, -0.78; 95% CI, -0.95 to -0.62) concentration, a high unsaturation degree of fatty acids (standardized median difference, 0.59; 95% CI, 0.42-0.81), and apolipoprotein B to apolipoprotein A1 ratio (standardized median difference, -0.88; 95% CI, -1.08 to -0.67). Adding aerobic fitness into the regression model after age, education, smoking, use of alcohol, and dietary factors accounted for more than an additional 5% of variation for 25 metabolome measures (R2 range, 5.01%-15.90% by measure). With these 2 criteria, maximal muscular strength was not associated with any metabolome measures. Aerobic fitness was associated with high large high-density lipoprotein particle concentration (R2, 14.97%; 95% CI, 10.65%-20.85%), low apolipoprotein B to apolipoprotein A1 ratio (R2, 14.49%; 95% CI, 10.58%-19.51%), and low glycoprotein concentration (R2, 15.90%; 95% CI, 11.22%-21.51%). Aerobic fitness was also associated with low very low-density lipoprotein, triglyceride, isoleucine, leucine, phenylalanine, glycerol, and glycoprotein concentrations and with a high unsaturation degree of fatty acids. Adjusting for recent physical activity influenced the results minimally. Adjusting for body fat percentage showed that some of the associations were mechanistically associated with body fat percentage. This study provides data on the association of high aerobic fitness with underlying oxidative lipid metabolism associated with a reduction in cardiometabolic risk. High maximal muscular strength is not similarly associated with these benefits.

Housing conditions modulate spontaneous physical activity, feeding behavior, aerobic running capacity and adiposity in C57BL/6J mice

There is evidence of reduced adiposity in rodents living in a large cages (LC) as compared to animals housed in small cages (SC). Because spontaneous physical activity (SPA) provides an important portion of the total daily energy expenditure, an increase of SPA in rodents kept in LC could explain their reduced body fat accumulation. The relationship between SPA and components of physical fitness (i.e. aerobic and anaerobic fitness and body leanness) has not been previously determined. We examined the effects of eight weeks of LC exposure on SPA, body composition, feeding behavior, as well as aerobic and anaerobic running capacity in adult C57BL/6J mice. Male mice were housed in cages of two different sizes for 8 weeks: a small (SC, n = 10) and large (LC n = 10) cages with 1320 cm2 and 4800 cm2 floor space, respectively. SPA was measured gravimetrically, and food and water intake were recorded daily. Mice had critical velocity (CV) and anaerobic running capacity (ARC) evaluated at the beginning, middle course (4th week) and at the end of study (8th week). Despite non-significant differences in each week LC-mice were more active than SC-mice by considering all SPA values obtained in the entire period of 8 weeks. The difference in SPA over the whole day was mainly due to light phase activity, but also due to activity at dark period (from 6 pm to 9 pm and from 5 am to 6 am). LC-mice also exhibited higher food and water intake over the entire 8-wk period. LC-mice had lower content of fat mass (% of the eviscerated carcass) than SC-mice (SC: 8.4 ± 0.4 vs LC: 6.3 ± 0.3, p < 0.05). LC-mice also exhibited reduced epididymal fat pads (% of body mass) compared to SC-mice (SC: 1.3 ± 0.1 vs LC: 0.9 ± 0.1, p < 0.05) and retroperitoneal fat pads (SC: 0.4 ± 0.05 vs LC: 0.2 ± 0.02, p < 0.05). The LC-group showed significantly higher critical velocity than SC-group at the fourth week (SC: 14.9 ± 0.6 m·min−1 vs LC: 18.0 ± 0.3 m·min−1, p < 0.05) and eighth week (SC: 17.1 ± 0.5 m·min−1 vs LC: 18.8 ± 0.6 m·min−1, p < 0.05). Our findings demonstrate that eight weeks of LC housing increases SPA of C57BL/6J mice, and this may lead to reduced fat accumulation as well as higher aerobic fitness. Importantly, our study implies that SC limits SPA, possibly generating experimental artifacts in long-term rodent studies.

Capacidad aeróbica, dieta mediterránea y riesgo cardiometabólico en adultos

IntroductionUnhealthy lifestyle and inadequate diet could influence the development of future cardiometabolic disease. The main aim of this study was to determine the association between aerobic fitness and cardiometabolic risk factors in adults, whether this relation is depends of adherence to Mediterranean diet (MD). A secondary aim was to study the combined effect of aerobic capacity and adherence to MD on global cardiometabolic risk score (CMRS). MethodA total of 79 adults (38% women) enrolled between 18-40 year from Cádiz. We measured adiposity indicators, blood pressure, triglycerides, glucose and inflammatory profile (interleukin-6 and tumor necrosis factor) and was computed (CMRS). Aerobic fitness was measured by maximal oxygen comsuption through an incremental stress test by cycleergometer. The MD patterns was measured using the questionnaire of adherence to MD. The association between aerobic fitness and cardiometabolic risk factors was examined using a lineal regression and it was adjusted for different confounders. CMRS on the lifestyle was analyzed using the ANOVA test, with statistical significance level of P<0.05 in Bonferroni. ResultsLinear regression showed inverse association between aerobic fitness and cardiometabolic risk factors (all P≤0.05) in the model without adjustment. Blood pressure and triglycerides lost the association after adjust model for sex, age, and adherence to MD. Participants with high aerobic fitness and high adherence to MD show a lowest CMRS (−1.083±2.325 vs. 2.802±1.759). ConclusionsAerobic fitness was inversely associated with fatness risk factors, that relationship is independent to adherence to MD. A high adherence to MD could modulate blood pressure. A combination of high aerobic capacity and high adherence to MD could reduce the adverse consecuence of a low adherencie to MD.

AEROBIC FITNESS AND TYPE OF RECOVERY INFLUENCE POST-EXERCISE HEART RATE RECOVERY IN YOUNG WOMEN

This study aimed to analyze both influence of aerobic fitness and active recovery in heart rate (HR) reduction after maximum exercise (i.e. maximum incremental test) in untrained young women. Seventeen women were evaluated (23.88 ± 4.85 years), divided by the medium of peak of consumption of oxygen (30.80 mL.kg-1.min-1), in higher or lower aerobic fitness obtained during a maximum incremental test performed on a cycle ergometer. The post-exercise recovery was performed actively and passively, on two randomly non-consecutive days. It was noticed that HR at 6th and from the 6th to 10th min after the passive and active recovery, respectively, was lower in the higher aerobic fitness group, beyond that, the values of %HR reduction from the 6th to 10th min at 6th min after passive and active recovery, respectively, were higher in the higher aerobic fitness group. After active recovery, HR in 8th and 9th min and %HR reduction of the 8th to 10th min were lower and higher, respectively (p<0.05) than passive recovery in the lower aerobic fitness group. In short, the aerobic fitness influenced HR reduction after maximum exercise in untrained young women, mainly, after passive recovery. Besides that, the active recovery showed benefits in HR reduction in lower aerobic fitness group.

In vivo assessment of muscle mitochondrial function in healthy, young males in relation to parameters of aerobic fitness

PurposeThe recovery of muscle oxygen consumption (mdot{V}O2) after exercise provides a measure of skeletal muscle mitochondrial capacity, as more and better-functioning mitochondria will be able to restore mdot{V}O2 faster to the pre-exercise state. The aim was to measure muscle mitochondrial capacity using near-infrared spectroscopy (NIRS) within a healthy, normally active population and relate this to parameters of aerobic fitness, investigating the applicability and relevance of using NIRS to assess muscle mitochondrial capacity non-invasively.MethodsMitochondrial capacity was analysed in the gastrocnemius and flexor digitorum superficialis (FDS) muscles of eight relatively high-aerobic fitness (dot{V}O2peak ≥ 57 mL/kg/min) and eight relatively low-aerobic fitness male subjects (dot{V}O2peak ≤ 47 mL/kg/min). Recovery of whole body dot{V}O2, i.e. excess post-exercise oxygen consumption (EPOC) was analysed after a cycling protocol.ResultsMitochondrial capacity, as analysed using NIRS, was significantly higher in high-fitness individuals compared to low-fitness individuals in the gastrocnemius, but not in the FDS (p = 0.0036 and p = 0.20, respectively). Mitochondrial capacity in the gastrocnemius was significantly correlated with dot{V}O2peak (R2 = 0.57, p = 0.0019). Whole body dot{V}O2 recovery was significantly faster in the high-fitness individuals (p = 0.0048), and correlated significantly with mitochondrial capacity in the gastrocnemius (R2 = 0.34, p = 0.028).ConclusionNIRS measurements can be used to assess differences in mitochondrial muscle oxygen consumption within a relatively normal, healthy population. Furthermore, mitochondrial capacity correlated with parameters of aerobic fitness (dot{V}O2peak and EPOC), emphasising the physiological relevance of the NIRS measurements.