Higher VO2max Research Articles

Metabolic correlates of selection on aerobic capacity in laboratory mice:a test of the model for the evolution of endothermy

According to the aerobic capacity model of the evolution of endothermy, high levels of basal/resting metabolic rate (BMR/RMR) underlying endothermy have evolved as a correlated response to selection for high rates of aerobic metabolism (V(O(2)max)). To test the model we studied metabolic, behavioural and morphological correlates of replicated selection on maximum body mass-corrected metabolism elicited by swimming (V(O(2)swim)) in male laboratory mice. While 10 generations of selection did not change body mass, it resulted in a 12% difference in V(O(2)swim) between mice of selected and control line types and significant, correlated responses in maximum metabolic rates elicited by exposure to cold in a helium-oxygen atmosphere (V(O(2)He)), and during forced running on a motorized treadmill (V(O(2)run)). Selected and control lines also significantly differed with respect to duration of running (a measure of stamina, t(run)), and the distance run to exhaustion (d(e)). However, the selection protocol did not result in elevated BMR and voluntary activity. Higher V(O(2)max) in selected animals was positively correlated with higher masses of gastrocnemius muscles and heart but not of other visceral organs (intestine, stomach, liver and kidneys). These findings provide a mechanistic explanation for the lack of correlation between basal and maximal metabolic rates in selected mice. Overall, our study does not support the assumptions of the aerobic capacity model for the evolution of endothermy.

Performance-enhancing and thermoregulatory effects of intracerebroventricular dopamine in running rats

To assess the role of central dopamine on metabolic rate, heat balance and running performance, 2.0 µL of 5 × 10 − 3 M dopamine solution (DA) or 0.15 M NaCl (SAL) was intracerebroventricularly injected in Wistar rats 1 min before running on a motor-driven treadmill, according to a graded exercise protocol, until fatigue. Oxygen consumption (VO 2) and body temperature ( T b) were recorded at rest, during exercise, and after 30 min of recovery. DA induced a marked increase in workload (~ 45%, p < 0.05). At fatigue point, DA-injected rats attained ~29% higher maximum oxygen consumption (VO 2max) and ~0.75 °C higher T b than SAL-injected rats. Despite the higher VO 2max and T b attained during exercise, DA-treated rats reached VO 2 basal values within the same recovery period and dissipated heat ~33% faster than SAL-treated rats ( p < 0.05). The mechanical efficiency loss rate was ~40% lower in DA than in SAL-treated rats ( p < 0.05), however, the heat storage was ~35% higher in the DA group ( p < 0.05). Our results demonstrate that increased DA availability in the brain has a performance-enhancing effect, which is mediated by improvements in the tolerance to heat storage and increases in the metabolic rate induced by graded exercise. These data provide further evidence that central activation of dopaminergic pathways plays an important role in exercise performance.

Cardiorespiratory Responses to Maximal Arm and Leg Exercise in National-Class Marathon Runners

Marathon runners (MR) are among the most aerobically fit athletes in the world. Although aerobic capacity (VO2 max) during arm exercise generally varies between 64% and 80% of leg VO2max (mean 70%) in healthy men, few data are available regarding the comparative arm fitness of MR. To clarify the relationship between arm and leg fitness in MR, we studied 10 national-class MR (mean ± standard deviation age 30 ± 4 years) whose best marathon times averaged < 2 hours and 40 minutes. Each MR underwent lower and upper body maximal exercise evaluations with measurement of cardiorespiratory variables using indirect calorimetry during treadmill testing (standard Bruce protocol) and arm-crank ergometry, respectively. Our subjects achieved VO2max levels equaling 75.8 ± 7.1 mL/kg/min (5.2 ± 0.6 L/min) during treadmill testing, which was significantly higher than the level of cardiorespiratory fitness achieved during maximal arm exercise (45.4 ± 12.4 mL/kg/min [3.1 ± 0.9 L/min]; P < 0.01). In addition, maximal heart rate (183.2 ± 8.2 vs 163.7 ± 10 bpm) and systolic blood pressure (201.8 ± 10.1 vs 186.6 ± 12.1 mm Hg) were significantly higher (P < 0.01 and P < 0.05, respectively) during maximal leg versus arm exercise. Relative arm fitness (arm VO2max/leg VO2max) was extremely variable (41%–76%), averaging 60% ± 13%. Although MR are able to achieve significantly higher VO2max values during treadmill testing than those observed in the general population, their relative arm fitness appears to be slightly reduced. These findings add to and strongly support the specificity of measurement and training concept.

Steady exercise removes VO 2max difference between mitochondrial genomic variants

It has been clearly established that mitochondrial variants, among other potential factors, influence on VO 2max. With this study we sought to determine whether this genetic predisposition could be modified by steady exercise. Mitochondrial genetic variants were determined in 70 healthy controls (CON) and in 77 athletes who trained regularly (50 cyclists, aerobic training (AER), and 27 runners of 400 m, anaerobic training (NoAER)). All of them were male Spanish Caucasian individuals. A maximum graded exercise test (GXT) in cycle-ergometer was performed to determine VO 2max (mL kg −1 min −1). Our results confirmed that, in CON, VO 2max ( P = 0.007) was higher in Non-J than J individuals. Furthermore, we found that AER and NoAER showed, as it could be expected, higher VO 2max than CON, but not differences between mitochondrial variants have been found. According with these findings, the influence of mitochondrial DNA (mtDNA) variants on VO 2max has been confirmed, and a new conclusion has arisen: the steady exercise is able to remove this influence. The interest of these promising findings in muscular performance should be further explored, in particular, the understanding of potential applications in sport training and in muscle pathological syndromes.

Attenuated Postprandial Insulin Concentrations With Endurance Training Are Not Mediated By Reductions In Incretin Hormones

The incretin hormones, glucagon-like peptide-1 (GLP1) and glucose-dependent insulinotropic polypeptide (GIP), are released from the intestine after food ingestion and stimulate the pancreas to secrete insulin. Together, these hormones account for approximately half of the postprandial rise in plasma insulin concentrations. Although endurance exercise training improves insulin action on glucose disposal in skeletal muscle and results in a concomitant decrease in postprandial insulin secretion from the pancreas, it is not known if a reduction in incretin hormones contributes to the lower insulin response. PURPOSE: To determine if long-term endurance training is associated with lower plasma GLP1 and GIP responses to oral glucose ingestion. METHODS: Fifteen master endurance athletes (56 ± 2y) and 14 healthy non-exercising control subjects (57 ± 2y) underwent 2h, 75 g oral glucose tolerance tests (OGTTs) during which blood samples were acquired every 30 minutes to assess glucose, insulin, GLP1, and GIP concentrations by using commercially available assays. An index of insulin action (ISI) was calculated based on glucose and insulin concentration from the OGTT. VO2max was assessed using indirect calorimetry and body fat was quantified using DXA. RESULTS: Athletes had higher VO2max (54 ± 2 vs 34 ± 2 mL/kg/min; P < 0.0001) and lower body fat (14 ± 1 vs 23 ± 1%; P <0.0001) than controls. While the area under the curve (AUC) for glucose from the OGTT did not differ between groups (P = 0.12), athletes had 41% lower insulin AUC (P = 0.02) and two-fold greater ISI (0.001). Athletes and controls did not differ in terms of GLP1 AUC (346 ± 65 vs. 414 ± 80 pM·min, p= 0.52) or GIP AUC (19.4 ± 1.3 vs. 18.0 ± 1.4 ng/mL·min, P = 0.49). CONCLUSIONS: These findings suggest the lower postprandial insulin responses that occur in athletes are not modulated by reductions in postprandial concentrations of the intestinally derived incretin hormones, GLP1 and GIP. Supported by NIH General Clinical Research Center RR00036, NIH Clinical Nutrition Research Unit DK56341, Saint Louis University Beaumont Award, and the Longer Life Foundation.

Is Anaerobic Power Related To Vo2 Max Attainment?

PURPOSE: To determine if anaerobic power is related to VO2max attainment in recreationally-active men and women. METHODS: Nineteen subjects (10 men and 9 women, mean age, height, mass, and VO2max = 23.0 ± 4.1 yr, 174.1 ± 7.3 cm, 68.1 ± 10.7 kg, and 42.2 ± 6.0 mL/kg/min, respectively) initially completed the Wingate Test. At least 24 h later, subjects completed incremental cycle ergometry followed by 10 min of active recovery, then performed a verification protocol at a supramaximal workload one stage above the last completed stage during the incremental test. During exercise, gas exchange data were obtained every 15 s. VO2max was defined as a change in VO2 (DVO2) < 2.1 mL/kg/min. Day-to-day error in VO2max ranged from 3.0 - 3.2 % for the supramaximal and incremental protocol, respectively. A paired t-test was used to examine differences in VO2max and gas exchange data between tests. Linear regression was used to describe the relationship between DVO2 at VO2max and peak power, mean power, and fatigue index. RESULTS: Peak power, mean power, and fatigue index were equal to 9.4 ± 1.4 W/kg, 7.1 ± 1.0 W/kg, and 51.4 ± 5.6 %, respectively. Peak power and mean power significantly (p<0.05) predicted DVO2, DVO2 = 0.04(MP) - 0.03(PP) + 0.79, R=0.56, p = 0.05. There was no correlation between fatigue index and DVO2, r (19) = -0.29, p>0.05. There was no difference (p>0.05) in mean VO2max between the incremental (42.2 ± 6.0 mL/kg/min) and supramaximal trial (42.2 ± 5.4 mL/kg/min). VCO2 and RER were higher (p<0.05) in response to the incremental (3.42 ± 0.66 L/min and 1.20 ± 0.06) compared to the supramaximal protocol (3.13 ± 0.69 L/min and 1.09 ± 0.07), although maximal HR and VE were similar (p>0.05) between protocols. CONCLUSION: Linear regression revealed that mean and peak power are significant predictors of DVO2, yet they explain only 31 % of the variability in DVO2. Despite no difference in mean VO2max between protocols, there were three subjects who had a higher VO2max in the supramaximal trial, and five subjects who had a lower VO2max in the supramaximal trial versus the incremental bout. Additional investigation is needed to further elucidate the VO2max phenomenon, specifically why some subjects do not reveal a 'true‘ VO2max after completion of a verification protocol.

Submaximal Relative Mechanical Power Output Is A Requirement To Be A Professional Road Cyclist

Numerous studies in the scientific literature show the determinant performance factors in professional road cyclists. Nevertheless, there are some submaximal variables, probably related to endurance cycling performance, that remain to be studied. PURPOSE: To assess new physiological and mechanical factors that could be considered a requirement to become a professional cyclist. METHODS: 161 cyclists of different levels of performance (13 professional and 148 amateurs, age 20.9 ± 3.9 yr) performed a laboratory test on a cyclergometer. Warm-up: 100W·10 min-1, initial workload: 200 W followed by 30 W increments every 4 min until exhaustion. All the tests were performed throughout a 10 year-period during the competitive phase of a cycling season (February to May). Dietary intake and resting period were controlled two days before the tests in order to maximize the test results. Subsequently, relative (W·kg-1) and absolute (W) mechanical power output at different fixed blood lactate concentrations (2, 3, 4, and 5 mmol·l-1), maximal absolute and relative mechanical power output (Wmax·kg-1, Wmax), and VO2max, expressed as L·min-1, mL·kg-1·min-1, and mL·kg-3/4·min-1, were measured and further analyzed using a backward stepwise multivariate logistic regression analysis to evaluate the aforementioned physiological parameters as potential predictors to be a professional cyclist. The level of significance was set at P < 0.05. RESULTS: The logistic regression analysis showed that VO2max expressed as mL·kg-1·min-1 and L·min-1 as well as mechanical power output expressed in absolute or relative terms were not good predictors to become a professional cyclist. Nevertheless, VO2max expressed as mL·kg-3/4·min-1 (P<0,01), W·kg-1(3mM) (P<0,01), W·kg-1(4mM) (P<0,01), and W·kg-1(5mM) (P<0,05) were significant predictors for becoming a professional road cyclist. CONCLUSION: To become a professional cyclist it is important to have a high relative VO2max (mL·kg-3/4·min-1), W·kg-1(2mM), W·kg-1(4mM), W·kg-1(5mM). It is important to emphasize that W·kg-1 at different submaximal intensities is also an important requirement to become a professional road cyclist, although these variables have not been well studied in the past. This study opens a new perspective to evaluate the performance of professional road cyclists.

Evidence for the possible association between calcium transient of isolated ventricular cardiomyocytes and exercise capacity in rats

The association between the whole cell intracellular Ca2+ transients ([Ca2+]i) of isolated cardiomyocytes and intrinsic exercise capacity in rats was evaluated. Standard performance (SP; n= 120) and high performance (HP; n= 36) rats were previous selected in a treadmill progressive exercise test accordingly to total exercise time until fatigue (TTF). The SP group encloses rats with TTF between 16.63 and 46.57 min and the HP encloses rats with TTF higher than 46.57 min. Oxygen consumption at the point of fatigue (VO2max) was measured by an open‐flow indirect calorimeter. The [Ca2+]i transients were measured by confocal microscopy in cardiomyocytes loaded with fluo‐4 AM. Statistical significance was assessed by t test, Mann‐Whitney test and linear regression (means ± SE). The study was approved by the Ethical Committee at the Federal University of Minas Gerais. The HP rats presented high VO2max (56.72 ± 0.54 mL.Kg−1.min−1, n= 6) when compared to SP rats (40.01 ± 0.42 mL.Kg−1.min−1, n= 6; P≤0.05). The [Ca2+]i transient peak was 4.18 ± 0.12 and 5.79 ± 0.34 for SP (n= 5 rats and 83 cells) and HP (n = 4 rats and 61 cells) groups, respectively (P≤0.05). The [Ca2+]i transient peak was positively correlated with the maximal treadmill speed in the progressive test (r = 0.81; P≤0.05). The data indicated that the high intrinsic exercise capacity is closely related to higher [Ca2+]i transients in isolated ventricular cardiomyocytes.

Exercise-induced prostacyclin release positively correlates with VO2max in young healthy men

In this study we have evaluated the effect of maximal incremental cycling exercise (IE) on the systemic release of prostacyclin (PGI(2)), assessed as plasma 6-keto-PGF(1alpha) concentration in young healthy men. Eleven physically active - untrained men (mean +/- S.D.) aged 22.7 +/- 2.1 years; body mass 76.3 +/- 9.1 kg; BMI 23.30 +/- 2.18 kg . m(-2); maximal oxygen uptake (VO(2max)) 46.5 +/- 3.9 ml . kg(-1) . min(-1), performed an IE test until exhaustion. Plasma concentrations of 6-keto-PGF(1alpha), lactate, and cytokines were measured in venous blood samples taken prior to the exercise and at the exhaustion. The net exercise-induced increase in 6-keto-PGF(1alpha) concentration, expressed as the difference between the end-exercise minus pre-exercise concentration positively correlated with VO(2max) (r=0.78, p=0.004) as well as with the net VO(2) increase at exhaustion (r=0.81, p=0.003), but not with other respiratory, cardiac, metabolic or inflammatory parameters of the exercise (minute ventilation, heart rate, plasma lactate, IL-6 or TNF-alpha concentrations). The exercise-induced increase in 6-keto-PGF(1alpha) concentration?? was significantly higher (p=0.008) in a group of subjects (n=5) with the highest VO(2max) when compared to the group of subjects with the lowest VO(2max), in which no increase in 6-keto-PGF(1alpha) concentration was found. In conclusion, we demonstrated, to our knowledge for the first time, that exercise-induced release of PGI(2) in young healthy men correlates with VO(2max), suggesting that vascular capacity to release PGI(2) in response to physical exercise represents an important factor characterizing exercise tolerance. Moreover, we postulate that the impairment of exercise-induced release of PGI(2) leads to the increased cardiovascular hazard of vigorous exercise.

Cardiorespiratory fitness: relationship with the immune system of adolescents

This work to investigate the relationship between cardiorespiratory fitness with count of cells in the immune system (IS) in adolescents. The sample was composed by 102 boys (B) and 131 (G) girls (12 to 17 years-old). BMI was calculated and categorized (Cole et al.) and absolute and relative VO2max was obtained through the shuttle run test (Leger et al.) and categorized according to Rodrigues et al. Maturation stage was assessing (Tanner). The cells of IS by leukogram was obtained. It was hypothesized (H) that individuals with higher VO2max could present a higher ratio of chances in the counting of cells in the SI. Was used frequency distribution, Student t test, ANOVAs one-way and binary logistic regression (p< 0.05). The overweight was demonstrated that 27.8% (B) 13.2% (G). The values of VO2max were between 29 to 59 ml.kg-1.min-1 and 25 to 53 ml.kg-1.min-1 to B and G, respectively. The average of IS cells differ between B and G, and in greater range in the: Leukocytes (B = 5697.1 cel.ml and G = 6496.9 cel.ml; t= 3,959 p = 0,000), Segmented (B= 3288,1 cel.ml and G= 4023,8 cel.ml; t= 4,145; p= 0,000), and neutrophils (B = 3306,9 cel.ml and G = 4101.2 cel.ml; t= 4,431 , p= 0,000) in G, while Eosinophils (B = 286.1 cel.ml and G = 211.1 cel.ml; t= 2,644; p= 0,009) had a higher count for B. There were differences between the maturational stages only between puberty stage and pos puberty for Leukocytes and Segmented in G. The analyses of relative VO2max indicated the M with low cardiorespiratory fitness is 4,6; 2,76; 3,57 respectively have more chances of eosinophils, lymphocytes and monocytes below the 50th percentile, as well as to observe the absolute VO2max, the R with regular fitness is 9,0; 5,16; 9,65 respectively have more chances of leukocytes, monocytes and neutrophils below the 50th percentile. The M showed that the regular fitness has 3.0 times more chances to have leukocytes and neutrophils below the 50th percentile. It is concluded that the higher the VO2max, the better the counting of cells of the SI in adolescents.

Aerobic exercise: bioenergetics, physiologicaladjustments, fatigue and performance indices

The objective of this study was to present relevant updated information regarding the physiological determinants of aerobic training and performance. In contrast to common concepts, the aerobic metabolism rapidly responds to energy requirements, with the anaerobic and aerobic energy systems equally contributing to total energy production during maximal exercise lasting about 75 s. However, in the case of longer exercise duration the possible mechanisms of fatigue related to anaerobic metabolism are still the main determinants of exercise tolerance. Prolonged exercise (more than one hour) can be limited by several factors such as substrate depletion, water and electrolyte disturbance, or problems related to thermoregulation leading to an increase in body temperature. The most important variables of endurance performance have been organized into a model that integrates factors such as maximum oxygen uptake (VO2max), blood lactate thresholds, and muscle efficiency. For highly trained athletes, in addition to a high VO2max, success in endurance events also requires the ability to exercise for prolonged periods at a high percentage of VO2max, as well as to efficiently convert the energy produced into muscle work. Depending on the duration of the aerobic event, the training sessions should be aimed at improving VO2max, anaerobic lactate capacity and acidosis tolerance in the case of short-lasting events and aerobic capacity for events of intermediate duration, and at increasing muscle glycogen content and fat utilization in the case of long-lasting events.

Longitudinal changes in haemoglobin mass and VO2max in adolescents

This study assessed the relationship between haemoglobin mass (Hb(mass)) and maximum oxygen consumption (VO(2max)) in adolescents over 1 year. Twenty-three subjects (11-15 years) participated; 12 undertook ~12 months of cycle training (cyclists) and 11 were sedentary (controls). Hb(mass) and VO(2max) were measured approximately every 3 months. At baseline there was a high correlation (r = 0.82, P < 0.0001) between relative VO(2max) (ml kg(-1) min(-1)) and relative Hb(mass) (g kg(-1)). During 12 months there was a significant increase in relative VO(2max) of the cyclists but not the controls; however, there was no corresponding increase in relative Hb(mass) of either group. The correlation between percent changes in relative VO(2max) and relative Hb(mass) was not significant for cyclists (r = 0.31, P = 0.33) or controls (r = 0.42, P = 0.19). Training does not increase relative Hb(mass) in adolescents consistent with a strong hereditary role for Hb(mass) and VO(2max). Hb(mass) may be used to identify adolescents who have a high VO(2max).

Cardiorespiratory Fitness Predicts Changes in Adiposity in Overweight Hispanic Boys

We have previously shown that cardiorespiratory fitness predicts increasing fat mass during growth in white and African-American youth, but limited data are available examining this issue in Hispanic youth. Study participants were 160 (53% boys) overweight (BMI>or=85th percentile for age and gender) Hispanic children (mean+/-s.d. age at baseline=11.2+/-1.7 years). Cardiorespiratory fitness, assessed by VO2max, was measured through a maximal effort treadmill test at baseline. Body composition through dual-energy X-ray absorptiometry and Tanner stage through clinical exam were measured at baseline and annually thereafter for up to 4 years. Linear mixed models were used to examine the gender-specific relationship between VO2max and increases in adiposity (change in fat mass independent of change in lean tissue mass) over 4 years. The analysis was adjusted for changes in Tanner stage, age, and lean tissue mass. In boys, higher VO2max at baseline was inversely associated with the rate of increase in adiposity (beta=-0.001, P=0.03); this effect translates to a 15% higher VO2max at baseline resulting in a 1.38 kg lower fat mass gain over 4 years. However, VO2max was not significantly associated with changes in fat mass in girls (beta=0.0002, P=0.31). In overweight Hispanic boys, greater cardiorespiratory fitness at baseline was protective against increasing adiposity. In girls however initial cardiorespiratory fitness was not significantly associated with longitudinal changes in adiposity. These results suggest that cardiorespiratory fitness may be an important determinant of changes in adiposity in overweight Hispanic boys but not in girls.

Cardiorespiratory Fitness as a Feature of Metabolic Syndrome in Older Men and Women

OBJECTIVE—We studied the associations of cardiorespiratory fitness with metabolic syndrome in older men and women, because such data are limited in representative population samples. RESEARCH DESIGN AND METHODS—We studied a population sample of 671 men and 676 women aged 57–79 years at baseline of a randomized controlled intervention study. We assessed maximal oxygen uptake (Vo2max) by respiratory gas analysis during a maximal bicycle exercise test. RESULTS—Vo2max had a strong, inverse, and graded association with the risk of having metabolic syndrome as defined by the National Cholesterol Education Program criteria. Men and women in the lowest third of Vo2max had 10.2- and 10.8-fold higher risks and those in the middle third had 2.9- and 4.7-fold higher risks (P &amp;lt; 0.001 all) of metabolic syndrome than those with the highest Vo2max after multivariable adjustments. Factor analysis generated a principal factor that was strongly loaded by the main components of metabolic syndrome and Vo2max (−0.68 in men and −0.70 in women). CONCLUSIONS—Low cardiorespiratory fitness is associated with metabolic syndrome in older men and women. Our findings suggest that low cardiorespiratory fitness could be considered a feature of metabolic syndrome.

Pico de consumo de oxigênio em nadadores e escolares do sexo masculino

The objectives of this study were: a) to analyze the behavior of VO2MAX (absolute and relative) of males of different age groups sex; b) to compare VO2MAX (absolute and relative), of swimmers (SWM) and schoolchildren (SCH) in the same age groups. Seventy-one boys aged 7-17 years were evaluated (35 SWM and 36 SCH) and distributed into the age groups 7-10, 11-14 and 15-17 years. Anthropometric measurements were taken (height, body mass and sum of skin folds) and the metabolic (VO2MAX) tests were carried out using VO2000® gas analysis and an Inbrasport ATL® treadmill, using a modified version of the Bruce protocol. Statistical analysis: ANOVA for repeated measures, followed by Tukey’s post hoc test (p<0.05). Absolute VO2MAX: there were statistically significant differences between all age groups and between SWM (0.99 + 0.20 and 1.27 + 0.21 L.min-1) and SCH (0.98 + 0.36 and 0.80 + 0.12 L.min-1). Relative VO2MAX: there were statistically significantdifferences between SWM1 and SWM2 (10.88 + 0.09 and 0.75 + 0.47 ml.kg-1.min-1) and between SCH1 and SCH3 (6.96 + 1.23 and 0.98 + 2.29 ml.kg-1.min-1), although SWM and SCH were different. The results indicate that VO2MAX increased as the subjects got older, which is the result of natural development. However, the effect of swimming training predominated. Although the behavior of the variable was similar for the 11-14 and 15-17 age groups, the figures for SWM and SCH are different at these ages, with the swimmers having higher VO2MAX.

Peak oxygen uptake in swimmers and pupils

The objectives of this study were: a) to analyze the behavior of VO2MAX (absolute and relative) of males of different age groups sex; b) to compare VO2MAX (absolute and relative), of swimmers (SWM) and schoolchildren (SCH) in the same age groups. Seventy-one boys aged 7-17 years were evaluated (35 SWM and 36 SCH) and distributed into the age groups 7-10, 11-14 and 15-17 years. Anthropometric measurements were taken (height, body mass and sum of skin folds) and the metabolic (VO2MAX) tests were carried out using VO2000® gas analysis and an Inbrasport ATL® treadmill, using a modified version of the Bruce protocol. Statistical analysis: ANOVA for repeated measures, followed by Tukey’s post hoc test (p<0.05). Absolute VO2MAX: there were statistically significant differences between all age groups and between SWM (0.99 + 0.20 and 1.27 + 0.21 L.min-1) and SCH (0.98 + 0.36 and 0.80 + 0.12 L.min-1). Relative VO2MAX: there were statistically significantdifferences between SWM1 and SWM2 (10.88 + 0.09 and 0.75 + 0.47 ml.kg-1.min-1) and between SCH1 and SCH3 (6.96 + 1.23 and 0.98 + 2.29 ml.kg-1.min-1), although SWM and SCH were different. The results indicate that VO2MAX increased as the subjects got older, which is the result of natural development. However, the effect of swimming training predominated. Although the behavior of the variable was similar for the 11-14 and 15-17 age groups, the figures for SWM and SCH are different at these ages, with the swimmers having higher VO2MAX.

The possible influence of osteoarthritis of the knee on the accumulation of coronary risk factors in postmenopausal obese women

This cross-sectional study was designed to clarify the association between osteoarthritis of the knee (OAK) and coronary risk factors in postmenopausal obese women. The subjects consisted of 72 postmenopausal obese women (mean age 60.3 ± 7.6 years) with coronary risk factors. They were divided into two groups; including the OAK group and the normal knee (control) group. Aerobic capacity was evaluated by maximal oxygen uptake (VO2 max) estimated from the nomogram of Åstrand and Ryhming. Daily activity was measured by a single-axis accelerometer. After adjusting for the age, the OAK group (n = 37) showed significantly higher obesity indices, the number of coronary risk factors, incidence of Metabolic Syndrome, a lower aerobic capacity and a lower daily activity than control group (n = 35). After adjusting for the age, body weight and body mass index, the OAK group with a high waist circumference, a low VO2 max and low mean total energy expenditure showed a significantly higher number of coronary risk factors than the control group with a low waist circumference, high VO2 max and high total energy expenditure. These results suggest that OAK was therefore associated with the aerobic capacity, daily activity and Metabolic Syndrome, and it may indirectly influence for the development of the future coronary heart disease in postmenopausal obese women.

V˙O2max, Protocol Duration, and the V˙O2 Plateau

The purpose of this study was to compare VO2max, VO2-time slopes at the end of the protocol (last 30 s), and the presence of a VO2 plateau (VO2-time slope < 0.05 L.min(-1) during the last 30 s) across four protocol durations (5, 8, 12, and 16 min) during incremental cycling exercise to VO2max. Eight male (23.8 +/- 3.2 yr) and eight female (26.0 +/- 8.9 yr) subjects of moderate to high fitness levels participated in the study. VO2max was significantly higher in men than in women for each protocol duration, with main effect means of 4.23 versus 2.84 L.min(-1), respectively. For women, VO2max did not differ between any protocol duration. For men, VO2max for the 8-min protocol (4.44 +/- 0.39 L.min(-1)) was significantly higher than for all other protocol durations. Analysis of covariance, using the highest VO2max as the covariate, removed all protocol-duration significance for men. The VO2 slope for the final 30 s of each test was significantly lower for the 16-min protocol compared with the 5-min protocol, for both men and women. The ventilation threshold across four protocols was similar, at approximately 76% of VO2max for both men and women. The protocol duration of tests to VO2max should be between 8 and 10 min for healthy, moderately to highly trained subjects.

Inflammatory and aerobic fitness discrimination of Metabolic Syndrome Patients

Inflammatory and aerobic fitness discrimination of Metabolic Syndrome Patients Franz H. P. Burini, Avany F. Pereira, Roberto C. Burini CeMENutri - UNESP, SP, Brazil; PRONUT - USP, SP, Brazil Metabolic Syndrome (MS) is a major cardiovascular risk factor, and has been associated with others risk factors, such as pro-inflammatory status and low cardiorrespiratory fitness (VO2max.). Little is know about the influence of inflammatory markers on VO2max., and the influence of MS in this relationship. PURPOSE: To evaluate the influence of pro-inflammatory status in VO2max., and its relation with Metabolic Syndrome. METHODS: We assessed 158 subjects (44 males and 144 females; 54 ± 9 years of age), for plasma biochemistry (including hs-CRP, HDL-cholesterol, glucose and triglycerides), clinical evaluation (vital signs) and cardiorrespiratory fitness - VO2max. (treadmill stress test by Balke protocol). For MS diagnosis we used ATP III (NCEP, 2001) criteria. All subjects were participants (volunteers) in a lifestyle changing program and an informed consent was obtained. Value comparisons were made using t Student test, adopting 5% as significance level. RESULTS: Pro-inflammatory status discriminated VO2max. (hs-CRP P25 vs P75: 37.6 ± 12.2 vs 32.5 ± 11.1 mL-1.kg-1.min-1) whereas in the higher pro-inflammatory status group (hs-CRP P75), MS patients showed lower VO2max. (27.3 ± 12.1 vs 34.9 ± 10.3 mL-1.kg-1.min-1). CONCLUSIONS: We suggest that high VO2max. is associated with low hs-CRP; and MS patients with high hs-CRP should focus their treatment on non-drug strategies, such as physical activity.

Influence of Physical Activity and VO2max in Coronary Risk in Subjects Aged Over 40

Similarly to what is observed in developed countries, coronary heart disease (CHD) is a major cause of death in Brazil. Risk factors for CHD have been compiled in scores which are influenced by physical activity and fitness in the general population. PURPOSE: To assess the influence of cardio-respiratory fitness (CRF) and physical activity pattern over CHD risk in Brazilian Army military personnel aged 40 years and more. METHODS: Blood lipid profile, blood pressure and glycemia status were measured after 12 hours fasting in 973 male subjects. Smoking habits and physical activity patterns were obtained by means of questionnaires. All data collected were used to calculate the 10 yr Framinghan risk score (FRS). The CRF index used was VO2max, which was estimated by a 12 min-run test using Cooper equation. Subjects were stratified in low FRS (below 10%), mean FRS (from 10% to 19%) and high FRS (above 19%) groups. RESULTS: Subjects' age was 44.5 ± 3.95 (mean±sd) years and Body Mass Index (BMI) was 26.3 ± 3.6 kg.m-2. Most of the subjects (76.2%) had low RC and just a few of them showed high RC (3.1%). Approximately, only 75% of the subjects exercised regularly (at least 60 min per session, 3+ times a week). These regularly active males presented lower prevalence (p<0.05) of high FRS (2.3%) when compared to the rest of the subjects (4.2%). Physical activity characteristics also influenced (p<0.05) the FRS - subjects who exercised for at least 60 min per session and at high intensity showed lower values in comparison to subjects who exercised for less than 30 min (0.8 vs. 4.1%, respectively) and at low intensity (1.2 vs. 5.1%, respectively). Subjects with the highest VO2max (above 70th percentile - ACSM, 2006) had significantly (p<0.001) lower FRS (0.2%) than subjects with average (1.4%) or below average CRF (below 30th percentile, 4.9%). CONCLUSIONS: CRF and physical activity characteristics (frequency, intensity and duration) may significantly protect subjects against CHD events, even in a homogeneous sample of physically active males, according to FRS.