132 research outputs found

    Anaerobic Contributions Are Influenced by Active Muscle Mass and The Applied Methodology in Well-Controlled Muscle Group

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    International Journal of Exercise Science 15(7): 599-615, 2022. The anaerobic metabolism determination is complex and the applied methodologies present limitations. Thus, the purpose of this study was to investigate the effects of different calculations (MAOD vs. AOD) on the anaerobic contribution using the dynamic knee extension. Twenty-four male were recruited [Mean (SD); age 27 (1) years, body mass 90 (3) kg, height 181 (2) cm]. This study was divided into two independent experiments (EXP1: ­one-legged; EXP2: two-legged). In both experiments, it was performed a graded exercise test to determine maximal power (MP-GXT); 2-4 submaximal efforts (VO2-intensity relationship); and an exhaustive effort. The theoretical energy demand for the exhaustive effort (TEDex) was constructed from the submaximal efforts. Therefore, MAOD was assumed as the difference between the TEDex and the accumulated VO2 (AVO2). In contrast, the energy demand for AOD was calculated as the product between VO2 at the end of exercise and time to exhaustion (TEDaod). Thus, AOD was assumed as the difference between TEDaod and AVO2. Bayesian paired t-test was used to compare the differences between the applied methods. Also, correlations between the anaerobic indices and performance were verified. In EXP1, AOD was higher than MAOD [1855 (741) vs. 434 (245); BF10 = 2925; ES = 2.5]. In contrast, in EXP2, MAOD was higher than AOD [2832 (959) vs. 1636 (549); BF10 = 3.33; ES = 1.4]. Also, AOD was correlated to performance (r = .59; BF10 = 4.38). We concluded that MAOD and AOD are a distinct phenomenon and must be utilized according to the exercise model

    Dynamics of Recovery of Physiological Parameters After a Small-Sided Game in Women Soccer Players

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    Purpose: Training methods based on small-sided game (SSG) seem to promote physiological and tactical benefits for soccer players as they present characteristics more specific to the game. Thus, the main objective of the present study was to analyze the hormonal, biochemical, and autonomic parameters in an acute manner and the recovery dynamics (up to 72 h after) in a SSG.Methods: Thirteen professional female soccer players participated in the study (18.8 ± 0.8 years, body mass 59.4 ± 6.2 kg, and height 1.68 ± 0.05 m). During and after the SSG session (4 min × 4 min separated by 3 min of passive interval and 120 m2 coverage per player), autonomic modulation was analyzed in the time and frequency domains using heart rate variability, and blood samples (5 ml) were collected before (0 h) and after (10 min and 24, 48, 72 h) the SSG for biochemical and hormonal analysis.Results: The SSG induced an increase effect for LF (low frequency) (92,52%; Very likely increase) and a decrease effect for HF (high frequency) values (-65,72%; Very likely decrease), after 10 min of recovery. The LF/HF increase after 10 min of recovery (386,21%; Very likely increase). The RMSSD (square root of the mean squared differences of the successive N–N intervals) and pNN50 (measure of the number of adjacent NN intervals which differ by more than 50 ms) values presented a decrease effect 10 min after SSG (61,38%; Very likely decrease and-90%; Very likely decrease). The CK (creatine kinase) values presented no changes 10 min after SSG. The LDH (lactate dehydrogenase) values presented an increase effect 10 min after the SSG (19,22%; Likely increase). Both testosterone and cortisol concentrations presented the same behavior after SSG, where no alterations were observed with after 10 min (<0,37%; Most likely trivial).Conclusion: The SSG promoted significant cardiovascular stress that was restored within the first 24 h of recovery. Parasympathetic parameters continued to increase while sympathetic parameters declined significantly during the 72 h of recovery. In addition, the reduced game did not alter biochemical or hormonal responses during the 72 h

    Comparison of aerobic capacity determined by the lactate minimum test among guard, forward and forward-center positions in basketball players

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    To aim of this study was to verify the aerobic capacity by lactate minimum test (LM) among different positions in professional basketball players. Twelve high performance basketball players (12 Major National Leagues, 26.7± 3.2 years) were evaluated by LM. The method of lactate elevation consisted of 6 maximum sprints of 35 m separated by 10 s of recovery each (Running Anaerobic Sprint Test). The progressive phase in LM consisted of 4 periods of 3 min each at 8, 10, 11 and 12 Km/h. After lactate elevation phase and progressive periods, 25μL samples of blood were collected to determine peak lactate (PL) concentration and relative lactate minimum concentration (LACc) respectively. The running speed at the LM was taken when the gradient of the line was zero. Anova one-way statistical was utilized to compare the intensity corresponding LM, LACc and PL (p≤0.05). The velocity (Km/h) of LM did not differ among positions: Guard LM= 9.46±0.17 Km/h; Forward LM= 9.60±0.68 Km/h and Forward-Center LM= 9.64±0.25 Km/h. The LACc did not differ: Guard LM= 3.55±0.51 mmol/L; Forward LM= 3.48±1.63 mmol/L and Forward-Center LM= 4.00±0.43 mmol/L. No changes occurred in PL: Guard LM= 8.35±1.41 mmol/L; Forward LM= 8.16±1.47 mmol/L and Forward-Center LM= 8.76±1.20 mmol/L. The aerobic capacity determined by LM did not differ among guard, forward and forward center basketball players

    Maximal lactate steady state in swimming tethered

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    This study investigated whether aerobic capacity (AC) in tethered swimming corresponds to maximal lactate steady state (MLSS) and its correlation with 30 min (V30) and 400m (V400) free swimming velocity. Twenty-five swimmers were submitted to an incremental tethered swimming test (ITS) with each stage lasting 3 minutes, initial load 20N, with 10N increments and a 30s interval to collect blood samples and lactatemia ([La-]). The abrupt increase in [La-] against force (F) corresponded to AC (ACBI). The points obtained for [La-] against force (N) were adjusted with an exponential curve model to determine AC corresponding to 3.5mmol.l-1 (AC3.5) and 4.0mmol.l-1 (AC4.0). Later swimmers performed maximum exercise for 30 minutes (V30) and 400m (V400) in free swimming. After one week, nine swimmers performed three random 30 minute tethered swimming exercises with 90%, 100%, and 110% intensity ACBI MLSS. Comparisons between ACs (AC3.5, AC4.0, and ACBI) were made by the one-way Anova test. Pearson correlation was used for possible correlations between ACs and between ACs and V30 and V400 (p0.91) and V400 (r\u3e0.63). We can conclude that ACBI corresponds to MLSS and both individually determined. AC and from the fixed lactate concentrations (3.5 and 4mM) can be used to predict mean 30 minute and 400m free swimming velocity

    Two different approaches to dry-land training do not improve the water performance of swimmers

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    International Journal of Exercise Science 16(6): 770-790, 2023. Literature diverges about the performance improvement after dry-land training. Thus, the objective of the present study was to compare the effect of two models of dry-land training. Twenty-nine swimmers were divided into three groups, combined strength and power training (PTG), only strength training (STG), and a control group (CG). Measurements were taken for six weeks, before dry-land exposure (M1), after four weeks of specific training with exposure to dry-land training by two groups (M2), and after two weeks of taper without exposure to dry-land training (M3). Strength in specific exercises, jumping tests, and 50, 100, and 200m freestyle performance were evaluated on M1 and M3, while hematological and strength parameters in tethered swimming were measured in M1, M2, and M3. PTG showed time-effect improvement for 200, 100, and 50m performance (

    The 400-m front crawl test : energetic and 3D kinematical analyses

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    The aim of the study was to verify the relative contributions of energetic and kinematic parameters to the performance in 400-m front crawl test. Fourteen middle-distance swimmers participated in the study. Oxygen consumption was measured directly and blood samples were collected to assay lactate concentration. Both oxygen consumption and lactate concentration were used to calculate the: (i) overall energy expenditure, (ii) anaerobic (alactic and lactic) and (iii) aerobic contributions. The mean centre of mass speed and intracycle velocity variation were determined through three-dimensional kinematic analysis. Mean completion time was 315.64±26.91s. Energetic contributions were as follows: 6.1±0.28% from alactic anaerobic metabolism, 5.9±0.63% from anaerobic lactic and 87.8±0.88% from aerobic. Mean intracycle velocity variation was 0.14±0.03. The results indicated that performance of 400-m test relies predominantly on aerobic power. Parameters such as lactate, mean speed, anaerobic lactic and alactic (kW) correlated with performance of 400-m test (p <0.05). Multiple linear regressions indicated that mean centre of mass speed and anaerobic alactic (kW) determined the 400-m test performance (R2=0.92). Even though the T400 is characterized by aerobic metabolism, the anaerobic alactic component cannot be negligible at this competition level

    Physical activity in the post-COVID-19: AEROBICOVID project design and perspectives

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    Durante a pandemia de COVID-19 estão sendo observados vários efeitos tardios, afetando a saúde e a funcionalidade dos acometidos. Por outro lado, foram observadas menores taxas de infecção pelo SARS-CoV-2 e gravidade dos sintomas em cidades de elevada altitude. Neste sentido, o projeto AEROBICOVID foi desenvolvido com a hipótese de que o exercício seria uma proposta importante para a melhoria da saúde e que a hipóxia promoveria benefícios adicionais no processo de recuperação. Participaram 84 pessoas com aproximadamente 30 dias desde a recuperação dos sintomas da COVID-19, 25 no grupo de controle e 59 divididos em três grupos de treinamento físico moderado. O projeto teve bons resultados no ensino, pesquisa e extensão, mas também enfrentou dificuldades na operacionalização. Estas experiências são a base para propostas futuras através de um projeto de extensão na Universidade de São Paulo e em uma Unidade de Saúde da Família, além de um projeto de pesquisa que desenvolverá uma nova tecnologia de hipóxia de baixo custo.During the COVID-19 pandemic, several late-onset impairments have been observed, affecting the health and functionality of those involved. On the other hand, lower SARS-CoV-2 infection rates and severity of symptoms were observed in high-altitude cities. In this sense, the AEROBICOVID project was developed with the hypothesis that exercise would be an important opportunity for health improvement and that hypoxia would promote additional benefits in the recovery process. The cohort was about 84 participants with approximately 30 days since the COVID-19 symptoms recovery, 25 in the control group, and 59 divided into three moderate physical training groups. The project had good results in teaching, research, and extension, but also faced difficulties in operationalization. This experience is the basis for future proposals through an extension project at the University of São Paulo and in a Family Health Unit, besides a research project that will develop a new low-cost hypoxia technology

    Short and long term effects of high-intensity interval training on hormones, metabolites, antioxidant system, glycogen concentration, and aerobic performance adaptations in rats

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    The purpose of the study was to investigate the effects of short and long term High-Intensity Interval Training (HIIT) on anaerobic and aerobic performance, creatinine, uric acid, urea, creatine kinase, lactate dehydrogenase, catalase, superoxide dismutase, testosterone, corticosterone, and glycogen concentration (liver, soleus, and gastrocnemius). The Wistar rats were separated in two groups: HIIT and sedentary/control (CT). The lactate minimum (LM) was used to evaluate the aerobic and anaerobic performance (AP) (Baseline, 6, and 12 weeks). The lactate peak determination consisted of two swim bouts at 13% of body weight (bw): (1) 30 s of effort; (2) 30 s of passive recovery; (3) exercise until exhaustion (AP). Tethered loads equivalent to 3.5, 4.0, 4.5, 5.0, 5.5, and 6.5% bw were performed in incremental phase. The aerobic capacity in HIIT group increased after 12 weeks (5.2 +/- 0.2% bw) in relation to Baseline (4.4 +/- 0.2% low), but not after 6 weeks (4.5 +/- 0.3% bw). The exhaustion time in HIIT group showed higher values than CT after 6 (HIIT = 58 +/- 5 s; CT = 40 +/- 7 s) and 12 weeks (HIIT = 62 +/- 7 s; CT = 49 +/- 3 s). Glycogen (mg/100 mg) increased in gastrocnemius for HIIT group after 6 weeks (0.757 +/- 0.076) and 12 weeks (1.014 +/- 0.157) in comparison to Baseline (0.358 +/- 0.024). In soleus, the HIIT increased glycogen after 6 weeks (0.738 +/- 0.057) and 12 weeks (0.709 +/- 0.085) in comparison to Baseline (0.417 +/- 0.035). The glycogen in liver increased after HIIT 12 weeks (4.079 +/- 0.319) in relation to Baseline (2.400 +/- 0.416). The corticosterone (ng/mL) in HIIT increased after 6 weeks (529.0 +/- 30.5) and reduced after 12 weeks (153.6 +/- 14.5) in comparison to Baseline (370.0 +/- 18.3). In conclusion, long term HIIT enhanced the aerobic capacity, but short term was not enough to cause aerobic adaptations. The anaerobic performance increased in HIIT short and long term compared with CT, without differences between HIIT short and long term. Furthermore, the glycogen super-compensation increased after short and long term HIIT in comparison to Baseline and CT group. The corticosterone increased after 6 weeks, but reduces after 12 weeks. No significant alterations were observed in urea, uric acid, testosterone, catalase, superoxide dismutase, sulfhydryl groups, and creatine kinase in HIIT group in relation to Baseline and CT7FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP04/01205-6; 06/58411-

    Anaerobic And Aerobic Performances In Elite Basketball Players.

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    THE PURPOSE OF THIS STUDY WAS TO PROPOSE A SPECIFIC LACTATE MINIMUM TEST FOR ELITE BASKETBALL PLAYERS CONSIDERING THE: Running Anaerobic Sprint Test (RAST) as a hyperlactatemia inductor, short distances (specific distance, 20 m) during progressive intensity and mathematical analysis to interpret aerobic and anaerobic variables. The basketball players were assigned to four groups: All positions (n=26), Guard (n= 7), Forward (n=11) and Center (n=8). The hyperlactatemia elevation (RAST) method consisted of 6 maximum sprints over 35 m separated by 10 s of recovery. The progressive phase of the lactate minimum test consisted of 5 stages controlled by an electronic metronome (8.0, 9.0, 10.0, 11.0 and 12.0 km/h) over a 20 m distance. The RAST variables and the lactate values were analyzed using visual and mathematical models. The intensity of the lactate minimum test, determined by a visual method, reduced in relation to polynomial fits (2nd degree) for the Small Forward positions and General groups. The Power and Fatigue Index values, determined by both methods, visual and 3rd degree polynomial, were not significantly different between the groups. In conclusion, the RAST is an excellent hyperlactatemia inductor and the progressive intensity of lactate minimum test using short distances (20 m) can be specifically used to evaluate the aerobic capacity of basketball players. In addition, no differences were observed between the visual and polynomial methods for RAST variables, but lactate minimum intensity was influenced by the method of analysis.42137-4

    Glycogen Kinetics of Wistar Rats: Different Exercise Intensities and Tissue Analyzed Influence

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    International Journal of Exercise Science 15(2): 289-299, 2022. The aim of this study is to verify the influence of the intensity on muscle and hepatic glycogen depletion and recovery kinetics of Wistar rats, submitted to three acute training sessions with equalized loads. 81 male Wistar rats performed an incremental test to determine maximal running speed (MRS) and divided into 4 groups: baseline group (Control; n = 9); low intensity training session (GZ1; n = 24; 48 minutes at 50% of MRS); moderate intensity group (GZ2; n = 24; 32 minutes at 75% of MRS) and high intensity group (GZ3; n = 24; 5x5 minutes and 20 seconds at 90% of MRS). Immediately after the sessions and after 6, 12 and 24 hours, 6 animals from each subgroup were euthanized for glycogen quantification in soleus and EDL muscles and liver. A Two-Way ANOVA and the Fisher\u27s Post-hoc test was used (p \u3c 0.05). Glycogen supercompensation occurred between 6 and 12 hours after exercise in muscle tissue and 24 after exercise in the liver. The muscle and hepatic glycogen depletion and recovery kinetics are not modulated by exercise intensity since the load was equalized, but effects were distinct in different tissues. Hepatic glycogenolysis and muscle glycogen synthesis processes seem to run in parallel
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