Comparison of international height and BMI-for-age growth references and their correlation with adiposity in Brazilian schoolchildren.

This study verified the diagnostic accuracy of the nutritional status classified by the international height and BMI references of the World Health Organization (WHO) (WHO/2007), International Obesity Task Force (IOTF/2012) and MULT (2023). The data pool was composed by 22 737 subjects aged five to 16 years from the Santos and Porto Alegre surveys. A correlation matrix between the z-scores of the BMI references and the skinfold measurements was calculated through the Pearson correlation coefficient (r), and the subject's nutritional status was classified according to the international growth references. The accuracy for diagnosing obesity was performed separately by sex and using the 95th percentile of the triceps and subscapular skinfold sum, while Lin's concordance coefficient, Bland-Altman method and the Cohen's Kappa coefficient (Kappa) were used to verify the concordance and reliability among the BMI references. The correlation matrix showed a high positive correlation among the BMI z-scores (r ≥ 0·99) and among the skinfold measurements (r ≥ 0·86). The prevalence of stunting was higher when applying the MULT reference (3·4 %) compared with the WHO reference (2·3 %). The Bland-Altman plots showed the lowest critical difference (CD) between the height references of WHO and MULT (CD = 0·22). Among the BMI references, the WHO obesity percentile presented lower performance than MULT for boys, presenting a lower +LR value (WHO = 6·99/MULT 18 years = 10·99; 19 years = 8·99; 20 years = 8·09) for the same -LR values (0·04). Therefore, MULT reference holds promise as a valuable tool for diagnosing childhood obesity, particularly when considering sex differences. This enhances its suitability for assessing the nutritional status of Brazilian schoolchildren.

Energetic responses of head-out water immersion at different temperatures during post-exercise recovery and its consequence on anaerobic mechanical power.

PURPOSE: While exercise recovery may be beneficial from a physiological point of view, it may be detrimental to subsequent anaerobic performance. To investigate the energetic responses of water immersion at different temperatures during post-exercise recovery and its consequences on subsequent anaerobic performance, a randomized and controlled crossover experimental design was performed with 21 trained cyclists. METHOD: Participants were assigned to receive three passive recovery strategies during 10 min after a Wingate Anaerobic Test (WAnT): control (CON: non-immersed condition), cold water immersion (CWI: 20 â„ƒ), and hot water immersion (HWI: 40 â„ƒ). Blood lactate, cardiorespiratory, and mechanical outcomes were measured during the WAnT and its recovery. Time constant (τ), asymptotic value, and area under the curve (AUC) were quantified for each physiologic parameter during recovery. After that, a second WAnT test and 10-min recovery were realized in the same session. RESULTS: Regardless the water immersion temperature, water immersion increased [Formula: see text] (+ 18%), asymptote ([Formula: see text]+ 16%, [Formula: see text] + 13%, [Formula: see text] + 17%, HR + 16%) and AUC ([Formula: see text]+ 27%, [Formula: see text] + 18%, [Formula: see text] + 20%, HR + 25%), while decreased [Formula: see text] (- 33%). There was no influence of water immersion on blood lactate parameters. HWI improved the mean power output during the second WAnT (2.2%), while the CWI decreased 2.4% (P < 0.01). CONCLUSION: Independent of temperature, water immersion enhanced aerobic energy recovery without modifying blood lactate recovery. However, subsequent anaerobic performance was increased only during HWI and decreased during CWI. Despite higher than in other studies, 20 °C effectively triggered physiological and performance responses. Water immersion-induced physiological changes did not predict subsequent anaerobic performance.

External Loads of Elite Soccer Referees: A Systematic Review with meta-analysis.

The objective of the present study was to describe the total and fragmented external loads, at different intensities, of soccer referees in European and South American competitions during official matches through a systematic review and meta-analysis of cross-sectional studies. A systematic review was conducted in April, 2020. In all, 32 studies were included, incorporating 578 referees evaluated in 3170 games through video analysis or a global positioning system. Regarding external loads, it was observed that the total average distance covered by the referees was 10,461.74 m, with running speeds predominantly below 13 km.h-1. The total distance covered by the referees in the European competitions was higher and more intense than that of the referees in the South American tournaments, being 11,187.02 m and 9319.61 m, respectively. We suggest that referees' training can be organized according to the distances found at different intensities, in which low-intensity races can be performed below 13 km.h-1 with distances of approximately 4500 m, while high-intensity training can be developed with speeds from 18 to 24 km.h-1 for approximately 800 m. In addition, planning must consider the competition characteristics.

Mathematical models to identify high-performance players for the Brazilian under-19 men's volleyball team.

The objective of this study was to identify parameters that best discriminate between selected and non-selected players for the Brazilian under-19 men's volleyball team and propose mathematical models to identify high-performance players. To this end, 18 selected (16.89±0.96 years) and 138 non-selected (16.91±0.74 years) players for the under-19 team were assessed for the training profile, anthropometric profile, and physical performance level. The discriminant function analysis was used to build the models, with a significance of α<0.05. The spike jump reach showed a greater correlation with the discriminant scores obtained in the two models (r=0.701; r=0.782). The 10 variables included in Model 1 helped identify 88.9% of the players selected in their group of origin; Model 2 - obtained by the spike jump reach and duration of playing experience - identified 83.3% of the players selected. Therefore, coaches should be aware that differences between the selected and non-selected players are multi-factorial, with the spike jump reach being the most relevant assessment factor. Furthermore, good players for the selection can be identified using the two models: Model 1 promises greater success with ten assessments, whereas Model 2 allows the identification of suitable players for the under-19 men's volleyball team with only two simple assessments.

Long-Term Effects of Three Water-Based Training Programs on Resting Blood Pressure in Older Women.

The aim of the study was to compare the effects of three water-based training on blood pressure (BP) in older women. A total of 57 participants were randomized into the following groups: (a) aerobic training (AT), (b) concurrent training in which resistance training progresses to the use of resistive equipment (CTRE), and (c) concurrent training in which resistance training progresses to multiple sets (CTMS). The participants trained twice a week for 16 weeks. Systolic BP decreased from pretraining to after 8 weeks of training and, subsequently, to after 16 weeks of training (AT: -6.53 mmHg, CTRE: -10.45 mmHg, and CTMS: -10.73 mmHg). Diastolic BP decreased from pretraining to after 8 and 16 weeks of training (AT: -6.23 mmHg, CTRE: -4.61 mmHg, and CTMS: -6.19 mmHg). Furthermore, 16% of the AT participants, 23% of the CTRE participants, and 28.5% of the CTMS participants were no longer classified as hypertensive. Water-based aerobic and concurrent training are efficient nonpharmacological measures to reduce BP in older women.

Acute glycemic and pressure responses of continuous and interval aerobic exercise in patients with type 2 diabetes.

BACKGROUND: Aerobic training has been widely indicated to patients with type 2 diabetes. However, there are still few studies comparing acute glycemic and blood pressure effects of different methods of aerobic training. The aim is to compare glycemic and pressure acute responses of continuous aerobic exercise to interval aerobic exercise in patients with type 2 diabetes. MATERIALS AND METHODS: This study is a randomized, crossover clinical trial. Fourteen patients with type 2 diabetes performed two sessions of aerobic training with different methods (continuous and interval). Continuous session had duration of 35 minutes with intensity of 85-90% of heart rate corresponding to anaerobic threshold (HRAT), while interval session had 45 minutes, with stimulus in intensity of 85-90% of HRAT with recovery in intensity under 85% of HRAT. Capillary glycemia, systolic and diastolic blood pressure were analyzed before and after the sessions. RESULTS: Patients were 63.5 ± 9.8 years old. Glycemia was reduced in both sessions (p < 0.001). Only glycemia measured at 25 minutes after continuous session was not lower than pre-session values. Systolic blood pressure was also reduced in both sessions (p = 0.010) with similar behavior between them. In the diastolic blood pressure, there were differences only between the values measured immediately after exercise and the values measured 20 minutes (p = 0.002) and 30 minutes after exercise (p = 0.008). CONCLUSION: Both continuous and interval aerobic exercise, in a same intensity, are effective for glycemic and pressure acute reductions in individuals with type 2 diabetes. For patients with greater risk of hypertension, we believe that the interval method is safer.

Effects of aerobic, resistance, and combined exercise training on insulin resistance markers in overweight or obese children and adolescents: A systematic review and meta-analysis.

OBJECTIVE: To assess the associations of aerobic, resistance, and combined exercise with changes in insulin resistance, fasting glucose, and fasting insulin in children and adolescents who are overweight or obese. DATA SEARCHES: MEDLINE via Pubmed, Cochrane-CENTRAL, SPORTDiscus, and LILACS. STUDY SELECTION: Randomized clinical trials of at least six weeks of duration that evaluated the ability of exercise training to lower at least one of the following outcomes: insulin resistance-HOMA, fasting glucose, and fasting insulin in children and/or adolescents classified as obese or overweight. DATA EXTRACTION AND ANALYSIS: Two independent reviewers extracted data and assessed the quality of the included studies. Differences (exercise training group minus control group) in the outcomes evaluated were analyzed using a random effects model. RESULTS: Of 1853 articles retrieved, 17 studies were included. The meta-analysis showed that physical training in general was not associated with a reduction in fasting glucose levels compared to the control, but it was associated with reductions in fasting insulin levels (-3.37µU/ml; CI 95%, -5.16µU/ml to -1.57µU/ml; I2, 54%, p=0.003) and HOMA (-0.61; CI 95%, -1.19 to -0.02; I2, 49%, p=0.040). In addition, each modality (aerobic, resistance, and combined) was compared to the control group. Aerobic exercise was associated with declines in fasting insulin levels (-4.52µU/ml; CI 95%, -7.40 to -1.65; I2, 65%, p=0.002) and in HOMA (-1.33; 95% confidence interval, -2.47 to -0.18; I2, 73%, p=0.005). CONCLUSIONS: Exercise training, especially aerobic training, is associated with the reduction of fasting insulin levels and HOMA in children and adolescents with obesity and overweight, and may prevent metabolic syndrome and type 2 diabetes.

Effects of aerobic exercise performed in fasted v. fed state on fat and carbohydrate metabolism in adults: a systematic review and meta-analysis.

This study aimed to verify the effect of aerobic exercise performed in the fasted v. fed states on fat and carbohydrate metabolism in adults. Searches were conducted in March 2015, and updated in July 2016, using PubMed®, Scopus and Cochrane databases (terms: 'fasting', 'exercise', 'aerobic exercise', 'substrate', 'energy metabolism', 'fat', 'glucose', 'insulin' and 'adult') and references from selected studies. Trials that compared the metabolic effects of aerobic exercise (duration ≤120 min) performed in the fasted v. fed states in adults were accepted. The outcomes evaluated were fat oxidation during exercise and the plasma concentrations of insulin, glucose and NEFA before and immediately after exercise; two independent reviewers extracted the data (A. F. V. and L. C.). The results were presented as weighted mean differences between treatments, with 95 % CI. Of 10 405 articles identified, twenty-seven studies - with a total of 273 participants - were included. There was a significant increase in fat oxidation during exercise performed in the fasted, compared with fed, state (-3·08 g; 95 % CI -5·38, -0·79; I 2 39·1 %). The weighted mean difference of NEFA concentrations was not significantly different between states (0·00 mmol/l; 95 % CI -0·07, 0·08; I 2 72·7 %). However, the weighted mean differences of glucose (0·78 mmol/l; 95 % CI 0·43, 1·14; I 2 90·8 %) and insulin concentrations (104·5 pmol/l; 95 % CI 70·8, 138·2; I 2 94·5 %) were significantly higher for exercise performed in the fed state. We conclude that aerobic exercise performed in the fasted state induces higher fat oxidation than exercise performed in the fed state.

Rating of perceived exertion in maximal incremental tests during head-out water-based aerobic exercises.

The present study aimed to assess the relationship between rating of perceived exertion (RPE) and percentage of peak oxygen uptake ([Formula: see text]) during three head-out water-based aerobic exercises. In addition, the RPE at the second ventilatory threshold (VT2) was also compared among them. Twenty young women performed head-out water-based maximal tests for the exercises stationary running (SR), frontal kick (FK) and cross-country skiing (CCS). RPE was monitored during the tests and the values corresponding to VT2 and training zones corresponding to 50-59%, 60-69%, 70-79%, 80-89% and [Formula: see text] were determined. Regression analysis, descriptive statistics and ANOVA with repeated measures were used. Significant relationships were observed between the RPE and [Formula: see text] (r = 0.858-0.893; P < 0.001) for all head-out water-based aerobic exercises. Average RPE ranged from 12.1-12.7 in the training zone corresponding to 50-59%, from 13.7-14.8 to 60-69%, from 15.8-16.4 to 70-79%, from 17.3-18.1 to 80-89% and from 18.5-18.9 to [Formula: see text]. No significant differences were found among the three head-out water-based aerobic exercises at VT2 (P > 0.05; SR: 16.1 ± 0.9, FK: 16.7 ± 1.5, CCS: 15.9 ± 1.3). The results support the use of RPE to control the relative intensity of training during head-out water-based aerobic exercises and indicate values near to 16-17 when targeting VT2 intensity for young women.

Supersets do not change energy expenditure during strength training sessions in physically active individuals.

BACKGROUND/OBJECTIVE: The energy expenditure (EE) in strength training (ST) is analyzed both during and after each training session. However, little information exists about the influence of strength exercises supersets on EE. We aimed to determine whether supersets of ST exercises influenced EE during and after one strength exercise session. METHODS: Twenty men were randomly divided to perform either a session with grouped exercises for the same muscle (GE: 26.6 ± 3.4 years; 17.4 ± 3.4 body fat) or a session with separated exercises (SE: 24.9 ± 2.6 years; 15.4 ± 5.9 body fat). Four exercises (5 sets of 8-10 maximum repetitions) for knee extensor muscles and shoulder horizontal flexor muscles were executed in both training sessions. The EE of each experimental session was obtained through the analysis of oxygen uptake during and after exercise (60 minutes postsession). RESULTS: Total work during the session and increases in lactate concentrations were similar between the GE and SE Groups. During exercise, EE was greater in the SE Group when compared with the GE Group (GE: 123.8 ± 14.36 kcal vs. SE: 131.77 ± 20.91 kcal). During the postexercise period, GE induced greater EE when compared with SE (GE: 25.12 ± 7.86 kcal vs. SE: 19.76 ± 5.53 kcal). However, the exercise sequence did not influence overall EE (GE: 148.92 ± 18.72 kcal vs. SE: 151.53 ± 17.97 kcal, p = 0.920). CONCLUSION: Our findings indicate that, in physically active men, ST supersets do not influence total EE during and 60 minutes after a single session.

Vertical ground reaction force responses to different head-out aquatic exercises performed in water and on dry land.

The purpose was to analyse the vertical ground reaction forces (Fz) of head-out aquatic exercises [stationary running (SR), frontal kick (FK), cross-country skiing (CCS), jumping jacks (JJ), adductor hop (ADH) and abductor hop (ABH)] at two cadences in both aquatic and dry land environments. Twelve young women completed two sessions in each environment, each consisting of three exercises performed at two cadences (first and second ventilatory thresholds - C1 and C2, respectively). Two-way and three-way repeated measures analysis of variance were used to the statistical analysis. The results showed that the peak Fz and impulse were significantly lower in the aquatic environment, resulting in values from 28.2% to 58.5% and 60.4% to 72.8% from those obtained on dry land, respectively. In the aquatic environment, the peak Fz was lower and the impulse was higher at the C1 than at the C2. Furthermore, it was observed that SR and FK (0.9-1.1 BW) elicited a significantly higher peak Fz values compared to the ADH and JJ exercises (0.5-0.8 BW). It can be concluded that the aquatic environment reduces the Fz during head-out aquatic exercises. It should be noted that its magnitude is also dependent on the intensity and the identity of the exercise performed.

Water-based exercise and quality of life in women: the role of depressive symptoms.

Several studieshave evaluated the relation of exercise to quality of life (QoL). To our knowledge, no study has evaluated the relation of water-based exercise to depressive symptoms and QoL, or the association between improvement in QoL and depressive symptoms in healthy women. The purpose of this study was to evaluate the association of water-based exercise with changes in QoL. Forty-seven women performed water-based combined exercise for 12 weeks. All participants improved in the physical and psychological domains of QoL. Decreases in depressive symptoms and improvements in maximal strength and aerobic capacity were found for all participants. A regression model revealed that depressive symptoms were associated with improvements in physical and psychological domains of QoL. The results showed that moderate intensity, water-based exercise improved physical and psychological domains of QoL, depressive symptoms, aerobic capacity, and muscular strength of women. Furthermore, the improvement in physical and psychological domains of QoL appeared to be mediated by the antidepressant effects of exercise, but not by changes in aerobic capacity or muscular strength.

Aerobic Exercise in the Aquatic Environment Suppresses the Plasma Renin Activity in Individuals with Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial.

To compare the acute effects of aquatic walking/running versus dry-land walking/running on blood glucose and plasma renin activity (PRA) in individuals with type 2 diabetes, participants with type 2 diabetes performed deep-water or dry-land walking and/or running sessions in a swimming pool or on an athletics track, respectively. Both sessions comprised seven blocks of 3 min at 85-90% of the heart rate deflection point (HRDP), interspersed with 2 min at <85% HRDP, totaling 35 min, with a 48 h interval between sessions. PRA and blood glucose were assessed before and immediately after the sessions. Generalized estimation equations were used to verify the session effects, with the Bonferroni post hoc test, considering the significance level as 0.05. Twelve individuals (53.2 ± 8.9 years) diagnosed with type 2 diabetes for 6.3 ± 6.34 years participated in the study. A reduction in PRA was found only after the aquatic session (-7.75 ng/mL/h; -69%; p: 0.034), while both aquatic and dry-land sessions similarly reduced the blood glucose levels (aquatic: -38 mg/dL, -21%; dry-land: -26 mg/dL, -14%; time effect, p = 0.007). Despite yielding similar glycemic reductions as dry-land walking/running, aquatic walking/running led to an expressive decrease in PRA among individuals with type 2 diabetes.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Correlations between linear sprint with the ball, linear sprint without the ball, and change-of-direction without the ball in professional female soccer players.

The evolution of female soccer is related to the increase in high-intensity actions and choosing the abilities that best characterize the players' performance. Determining the capabilities that best describe the players' performance becomes essential for coaches and technical staff to obtain the results more efficiently within the competitive calendar. Thus, the study aimed to analyze the correlations between performance in the 20-m sprint tests with and without the ball and the Zigzag 20-m change-of-direction (COD) test without the ball in professional female soccer players. Thirty-three high-level professional female soccer players performed the 20-m sprint tests without a ball, 20-m sprint tests with the ball, and the Zigzag 20-m COD test without the ball. The shortest time obtained in the three trials was used for each test. The fastest time in the three trials was used for each test to calculate the average test speed. The Pearson product-moment correlation test was applied to analyze the correlation between the performance in the tests. Pearson's product-moment correlation test was used to analyze the correlation between the performance in the trials, with a significance level of α < 0.05. The average speed in the 20-m sprint tests with ball showed very large and significant correlations with the speed in the Zigzag 20-m COD test (r = 0.822; p < 0.001; 95% CI = 0.666 to 0.909). The 20-m sprint tests with ball and 20-m sprint tests without ball showed moderate, positive and significant correlation (r = 0.363; p = 0.038; 95% CI = 0.023-0.628). The tests of 20-m sprint tests without ball and Zigzag 20-m COD test also showed moderate, positive and significant correlation (r = 0.415; p = 0.016; 95% CI = 0.084-0.664). The female-female soccer players with a better ability to change direction may also have a better technical ability to drive the ball at high speed. However, they will not necessarily be the fastest in the linear sprint without the ball. Coaches and technical staff may choose to perform tests seeking efficiency and practicality, especially in a congested competitive period.

Physiological comparisons between aquatic resistance training protocols with and without equipment.

The purpose of the present study was to compare the physiological responses of oxygen uptake (VO(2)) and energy expenditure (EE) in two different aquatic resistance training protocols performed with three sets of 20 seconds (3 × 20) and six sets of 10 seconds (6 × 10) and with and without Speedo Resistance Equipment. Ten young healthy women volunteers, familiar with exercises in an aquatic environment, participated in this study. The four separate protocols were randomly selected and performed at a 48-hour interval by the same instructor. The total time of the 3 × 20 protocol was 34 minutes and that of the 6 × 10 protocol was 43 minutes, and all exercises were performed at maximal speed and amplitude. Although the protocols had different total times, they included one minute of stimulus per muscle group and the same time intervals. EE(gross) and EE(net) values were higher in the 6 × 10 protocol than in the 3 × 20 one. The variables VO(2) and EE(min) did not present significant difference between the protocols. VO(2), EE(gross), EE(net) and EE(min) values were higher when the equipment was used (W situation) than when it was not (WO situation). In the postexercise analysis, the W situation also showed higher VO(2) and EE(gross) values than the WO situation. Therefore, this study suggests the use of Speedo Resistance Equipment to increase VO(2) and EE, and it also suggests lengthier aquatic resistance training to obtain greater EE values per session.

Aquatic Aerobic and Combined Training in Management of Type 2 Diabetes: The Diabetes and Aquatic Training Study (DATS): A Randomized Clinical Trial.

BACKGROUND: To compare the effects of aquatic aerobic and combined (aerobic more resistance) training on glycemic control and other cardiometabolic outcomes in patients with type 2 diabetes. METHODS: Patients were randomized to an aquatic aerobic training (AERO, n = 19; 57.5 [7.4] y; 9 [47%] women), or an aquatic combined training (COMBI, n = 19; 60.9 [7.4] y; 10 [53%] women), or an aquatic active procedure control (n = 19; 58.6 [9.7] y; 10 [53%] women) in 3 weekly sessions (50 min each), during 15 weeks. Glycated hemoglobin was the primary outcome, whereas insulin resistance markers, lipid profile, systemic inflammation, renin concentration, blood pressure, physical activity levels, and sitting time were secondary outcomes. RESULTS: Glycated hemoglobin was reduced in all groups (P = .021), although changes were more marked in AERO (-0.36%) and COMBI (-0.44%) than in active control (-0.26%) group. Lipid profile was similarly modified in all groups. Diastolic blood pressure and renin concentration were also reduced in all groups; however, renin showed more marked reductions in AERO (-17.7 uIU/mL) and COMBI (-15.1 uIU/mL) than in active control (0.2 uIU/mL) group. Fasting insulin, triglycerides, C-reactive protein, systolic blood pressure, walking time, and sitting time on weekends were not modified. CONCLUSION: AERO and COMBI presented similar effect to improve glycemic control and some cardiometabolic risk factors in patients with type 2 diabetes.

Relationship between knee extensor and flexor muscle strength and age in professional volleyball players.

We aimed to analyse the relationship of peak torque (PT) of the knee extensors (Ext) and flexors (Fle) with age, and the relationship between conventional ratio and age progression in volleyball players. A total of 41 elite male volleyball players (age: 25.0 ± 6.1 years, body mass: 93.0 ± 9.8 kg, height: 198.0 ± 6.8 cm) were evaluated in a isokinetic dynamometer at speeds of 60, 180 and 300 deg/s, and at dominant (D) and non-dominant (ND) legs. In general, the knee flexor and extensor muscles varied greatly among the athletes (from 81 to 156 N.m for flexors; from 116 to 250 N.m for extensors at 300 deg/s and at dominant side). The mass-specific PT of knee extensors showed strong and negative correlation with ageing at 60 and 180 deg/s (r = -0.52-0.62, p < 0.01). The conventional ratio showed regular and positive relationship at all evaluated velocities (60°.s-1, r = 0.453, p < 0.01; 180°.s-1, r = 0.498, p < 0.01; 300°.s-1, r = 0.316, p = 0.04). The results demonstrated that volleyball players are susceptible to age-related effects on muscular performance during their career; this finding illustrates the importance of adopting training strategies to improve the production of strength in the lower limbs, which is essential for vertical jumps.

Cardiorespiratory, neuromuscular and kinematic responses to stationary running performed in water and on dry land.

The purpose of this study was to analyze the cardiorespiratory, neuromuscular and kinematic responses obtained during the stationary running in aquatic and dry land environments. Twelve women took part in the experimental protocol. Stationary running was performed for 4 min at three submaximal cadences and for 15 s at maximal velocity, with the collection of kinematic (peak hip angular velocity (AV)), cardiorespiratory (oxygen uptake (VO(2))) and neuromuscular variables (electromyographic (EMG) signal from the rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and short head of the biceps femoris (BF) muscles) in land-based and water-based test protocols. Factorial ANOVA was used, with an alpha level of 0.05. AV was significantly higher when the exercise was performed on land, and became significantly higher as the execution cadence increased. Similarly, VO(2) was significantly higher in the land-based exercise and rose as cadence increased. With the increase in the submaximal execution cadences, there was no corresponding increase in the EMG signal from the VL, BF, RF and ST muscles in either environment, though such a significantly increase was seen between the submaximal cadences and the maximal velocity. Dry land presented significantly greater EMG signal responses for all muscles at the submaximal cadences, except for the ST muscle. However, at the maximal velocity, all the analyzed muscle groups showed similar responses in both environments. In summary, for both environments, cardiorespiratory responses can be maximized by increasing the submaximal cadences, while neuromuscular responses are only optimized by using maximal velocity.

Neuromuscular economy, strength, and endurance in healthy elderly men.

Declines in muscular strength resulting from reduced neural activity may influence the reduction in aerobic capacity in older men. However, there has been little investigation into the relationship between muscular strength and economy of movement during aerobic exercise in elderly subjects. Thus, the purpose of this study was to investigate the possible relationship between strength, aerobic performance, and neuromuscular economy in older men. Twenty-eight aged men (65 ± 4 years old) were evaluated in dynamic (1 repetition maximum test), isometric strength (maximal voluntary contraction), and rate of force development. Peak oxygen uptake, maximal workload, and ventilatory threshold were determined during a ramp protocol on a cycle ergometer. Throughout the same protocol, the neuromuscular economy (electromyographic signal) of the vastus lateralis was measured. Significant correlations were found between muscular strength, cardiorespiratory fitness, and neuromuscular economy (r = 0.43-0.64, p < 0.05). Our results suggest that cardiorespiratory capacity and economy of movement are associated with muscular strength during aging.