Aerobic fitness level modulates the effects of prior supramaximal exercise on pulmonary VO2 response during moderate-intensity exercise

The aim of this study was to analyze the influence of aerobic fitness on the effects of prior exercise on VO2response during subsequent moderate-intensity exercise. After determination of the lactate threshold (LT) and maximal VO2 (VO2max). 14 untrained subjects (UG) and 14 well-trained cyclists (TG) performed on different days and in random order, rest to moderate-intensity exercise transitions (6 minutes at 80% of LT), preceded by either no prior exercise or prior supramaximal exercise (PSE: two bouts of 1 minute at 120% of VO2max, with a 1-minute rest in between). Baseline VO2 was significantly increased (p<0.05) by PSE in both groups (UG: 0.39 ± 0.06 vs. 0.51 ± 0.15 L·min -1;TG: 0.37 ± 0.06 vs. 0.58 ± 0.14 L·min -1). In the TG group, the steady state VO2 was significantly increased by PSE (TG: 2.21 ± 0.38 vs. 2.07 ± 0.27 L·min-1, p<0.05; UG: 1.60 ± 0.27 vs. 1.60 ± 0.29 L· min-1, p>0.05). It can be concluded that aerobic fitness level influences the effects of PSE on VO2 response during moderate-intensity exercise. [J Exerc Sci Fit • Vol 7 • No 1 • 48-54 • 2009].

Short-term low-intensity blood flow restricted interval training improves both aerobic fitness and muscle strength

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Running-based anaerobic sprint test as a procedure to evaluate anaerobic power

The aim of this study was to evaluate the use of the running anaerobic sprint test (RAST) as a predictor of anaerobic capacity, compare it to the maximal accumulated oxygen deficit (MAOD) and to compare the RAST's parameters with the parameters of 30-s all-out tethered running on a treadmill. 39 (17.0±1.4 years) soccer players participated in this study. The participants underwent an incremental test, 10 submaximal efforts [50-95% of velocity correspondent to VO2MAX (vVO2MAX)] and one supramaximal effort at 110% of vVO2MAX for the determination of MAOD. Furthermore, the athletes performed the RAST. In the second stage the 30-s all-out tethered running was performed on a treadmill (30-s all-out), and compared with RAST. No significant correlation was observed between MAOD and RAST parameters. However, significant correlations were found between the power of the fifth effort (P5) of RAST with peak and mean power of 30-s all-out (r=0.73 and 0.50; p<0.05, respectively). In conclusion, the parameters from RAST do not have an association with MAOD, suggesting that this method should not be used to evaluate anaerobic capacity. Although the correlations between RAST parameters with 30-s all-out do reinforce the RAST as an evaluation method of anaerobic metabolism, such as anaerobic power.

Análise da cinética do VO2 no domínio severo do crawl em condição atada de nado

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Perfil de aptidão cardiorrespiratória em corredores jovens pela cinética do VO2 em testes progressivos e retangulares

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

High-intensity interval training and hypertension: Maximizing the benefits of exercise?

Essential arterial hypertension is the most common risk factor for cardiovascular morbidity and mortality. Regular exercise is a well-established intervention for the prevention and treatment of hypertension. Continuous moderate-intensity exercise training (CMT) that can be sustained for 30 min or more has been traditionally recommended for hypertension prevention and treatment. On the other hand, several studies have shown that high-intensity interval training (HIT), which consists of several bouts of high-intensity exercise (~85% to 95% of HRMAX and/or VO2MAX lasting 1 to 4 min interspersed with intervals of rest or active recovery, is superior to CMT for improving cardiorespiratory fitness, endothelial function and its markers, insulin sensitivity, markers of sympathetic activity and arterial stiffness in hypertensive and normotensive at high familial risk for hypertension subjects. This compelling evidence suggesting larger beneficial effects of HIT for several factors involved in the pathophysiology of hypertension raises the hypothesis that HIT may be more effective for preventing and controlling hypertension.

Prática de atividade física em estudantes das áreas de saúde e não saúde de uma universidade do interior de São Paulo

The world’s population is having more and more difficulties in performing their daily activities and leisure, becoming, this way, more sedentary. Sedentary lifestyle can be considered as a reduction or as a lack of physical activity, less than the minimum volume suggested by the World Health Organization (WHO). Physical activity changes the behavior and some environmental acts. This study aimed to identify the NAF of students in the area of Physical Education and Healt Nursing and compare it with identified students’ levels non-health areas, being Production Engineer and Pedagogy. Aimed to correlate the found volume of 15 participants, with the state of cardio respiratory fitness (VO2max). The study included 125 students of both sexes from a university located in São Paulo state country. We conducted a cross-sectional study from August to October of 2012. For the initial test of the volume of physical activity we used the International Physical Activity Questionnaire (IPAQ) long version. In order of assessing cardio respiratory fitness, the Katch and McArdle seat test (1981) was used. Data were analyzed according to Physical Activity Level (PAL) presented by the university students in sessions 1, 2, 3, 4 of the IPAQ, and 15 students’ results were correlated with VO2max test. From these results we can say that: IPAQ session 1 showed that students in the health area are statistically superior to the non-health students area to the high-active classification. In session 2 the results were significant and superior to the health area and very active in sedentary classification. The session 3 results were very similar to session 1, showing that the health area as high-active with statistics differences. In session 4 we can see very significant results for health area in high-active areas and irregular actives. A total of 4 sessions found significant results for very active and sedentary. When was the attempt of association between levels 15 participants found the IPAQ long version and test bank VO2max, the results showed no significant association. The results of this study show a need for policies to encourage physical activity in the University environment, emphasizing a greater need for students who do not work in healthcare.

Concordância entre dois testes de capacidade aeróbica máxima baseados na corrida em esteira e pista, com jogadores de futsal

The actual study goal is to test the Ellestad and Weltman protocol concordance in the prediction of VO2max in Futsal athletes. There was no significant difference between the two protocols, there was significant correlation between methods, but the Bland & Altman plotting shown very high amplitude in the Confident Interval at 95%.

Concordância dentre dois testes de capacidade aeróbia máxima em jogadores de futsal: teste de Ellestad e o vai e vem de 20m

O futsal é uma modalidade intermitente cuja a participação do metabolismo aeróbio é importante na ressíntese de ATP e CP gastos anaerobiamente. A capacidade aeróbia máxima (VO2max) pode ser mensurada por testes de campo e testes laboratoriais. Dentre os vários testes laboratoriais existentes, se destaca o teste de Ellestad, devido à sua segurança e capacidade diagnóstica de patologias cardíacas. Dentre os testes de campo se destaca o teste de Vai e Vem de 20m (VV20m), devido à sua alta validade e reprodutibilidade em adultos, e devido à alta especificidade ao futsal e ao futebol, comprovado pela existênicia de correlações significativas do desempenho no VV20m com várias medidas de performance no futebol. Porém, não existem estudos sobre a validação ou concordância do teste de Ellestad em atletas de esportes coletivos. Portanto, o objetivo do presente estudo foi testar a concordância do teste de Ellestad e o VV20m na predição do VO2max em atletas de futsal. Quinze jogadores semi-profissionais (25,4 ± 5,51 anos, 70,37 ± 5,74kg, 1,75 ± 0,04m e 8,43 ± 3,02% de gordura) realizaram os testes de Ellestad e o VV20m em ordens aleatórias, separados por quatro dias. A concordância foi testada pela comparação entre as diferenças (Teste t-studet para dados independentes), correlação (coeficiente de Pearson) e concordância (dipersão de Bland e Altman). Não houve diferença significativa entre os valores de VO2max estimados pelos dois protocolos, mas a correlação foi significativa (p < 0,05; r = 0,479; EPE: 1,8 mlO2×kg -1 ×min -1 ) entre os métodos. A análise de Bland e Altman apresentou concordância entre os testes para um intervalo de ±95% em torno da média da diferença (1,3 mlO2×kg -1 ×min -1 ), porém a dispersão indica um enviesamento positivo e significativo (p < 0,01), sugerindo que a a diferença aumenta com o aumento da média do VO2max. Assim, para atletas de alto rendimento, o teste de Ellestad não apresenta a mesma adequação na determinação do VO2max, quando comparado ao VV20m.

Nutritional and metabolic risk factors for insulin resistance in adults

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maternal Moderate Physical Training during Pregnancy Attenuates the Effects of a Low-Protein Diet on the Impaired Secretion of Insulin in Rats: Potential Role for Compensation of Insulin Resistance and Preventing Gestational Diabetes Mellitus

The effects of pregestational and gestational low-to-moderate physical training on insulin secretion in undernourished mothers were evaluated. Virgin female Wistar rats were divided into four groups as follows: control (C, n = 5); trained (T, n = 5); low-protein diet (LP, n = 5); trained with a low-protein diet (T + LP, n = 5). Trained rats ran on a treadmill over a period of 4 weeks before mate (5 days week(-1) and 60 min day(-1), at 65% of VO2max). At pregnancy, the intensity and duration of the exercise were reduced. Low-protein groups were provided with an 8% casein diet, and controls were provided with a 17% casein diet. At third day after delivery, mothers and pups were killed and islets were isolated by collagenase digestion of pancreas and incubated for a further 1 h with medium containing 5.6 or 16.7 mM glucose. T mothers showed increased insulin secretion by isolated islets incubated with 16.7 mM glucose, whereas LP group showed reduced secretion of insulin by isolated islets when compared with both C and LP + T groups. Physical training before and during pregnancy attenuated the effects of a low-protein diet on the secretion of insulin, suggesting a potential role for compensation of insulin resistance and preventing gestational diabetes mellitus.

Effects of an adapted physical activity program on the physical condition of elderly women: an analysis of efficiency

Background: Specific research tools and designs can assist in identifying the efficiency of physical activity in elderly women. Objectives: To identify the effects of physical activity on the physical condition of older women. Method: A one-year-long physical activity program (123 sessions) was implemented for women aged 60 years or older. Four physical assessments were conducted, in which weight, height, BMI, blood pressure, heart rate, absences, grip strength, flexibility, VO2max, and static and dynamic balance were assessed. The statistical analyses included a repeated measures analysis, both inferential (analysis of variance - ANOVA) and effect size (Cohen's d coefficient), as well as identification of the participants' efficiency (Data Envelopment Analysis - DEA). Results: Despite the observation of differences that depended on the analysis used, the results were successful in the sense that they showed that physical activity adapted to older women can effectively change the decline in physical ability associated with aging, depending on the purpose of the study. The 60-65 yrs group was the most capable of converting physical activity into health benefits in both the short and long term. The >65 yrs group took less advantage of physical activity. Conclusions: Adherence to the program and actual time spent on each type of exercise are the factors that determine which population can benefit from physical activity programs. The DEA allows the assessment of the results related to time spent on physical activity in terms of health concerns. Article registered in Clinicaltrials.gov under number NCT01558401.

Exercise training improves relaxation response and SOD-1 expression in aortic and mesenteric rings from high caloric diet-fed rats

Abstract Background Obesity has been associated with a variety of disease such as type II diabetes mellitus, arterial hypertension and atherosclerosis. Evidences have shown that exercise training promotes beneficial effects on these disorders, but the underlying mechanisms are not fully understood. The aim of this study was to investigate whether physical preconditioning prevents the deleterious effect of high caloric diet in vascular reactivity of rat aortic and mesenteric rings. Methods Male Wistar rats were divided into sedentary (SD); trained (TR); sedentary diet (SDD) and trained diet (TRD) groups. Run training (RT) was performed in sessions of 60 min, 5 days/week for 12 weeks (70–80% VO2max). Triglycerides, glucose, insulin and nitrite/nitrate concentrations (NOx-) were measured. Concentration-response curves to acetylcholine (ACh) and sodium nitroprusside (SNP) were obtained. Expression of Cu/Zn superoxide dismutase (SOD-1) was assessed by Western blotting. Results High caloric diet increased triglycerides concentration (SDD: 216 ± 25 mg/dl) and exercise training restored to the baseline value (TRD: 89 ± 9 mg/dl). Physical preconditioning significantly reduced insulin levels in both groups (TR: 0.54 ± 0.1 and TRD: 1.24 ± 0.3 ng/ml) as compared to sedentary animals (SD: 0.87 ± 0.1 and SDD: 2.57 ± 0.3 ng/ml). On the other hand, glucose concentration was slightly increased by high caloric diet, and RT did not modify this parameter (SD: 126 ± 6; TR: 140 ± 8; SDD: 156 ± 8 and TRD 153 ± 9 mg/dl). Neither high caloric diet nor RT modified NOx- levels (SD: 27 ± 4; TR: 28 ± 6; SDD: 27 ± 3 and TRD: 30 ± 2 μM). Functional assays showed that high caloric diet impaired the relaxing response to ACh in mesenteric (about 13%), but not in aortic rings. RT improved the relaxing responses to ACh either in aortic (28%, for TR and 16%, to TRD groups) or mesenteric rings (10%, for TR and 17%, to TRD groups) that was accompanied by up-regulation of SOD-1 expression and reduction in triglycerides levels. Conclusion The improvement in endothelial function by physical preconditioning in mesenteric and aortic arteries from high caloric fed-rats was directly related to an increase in NO bioavailability to the smooth muscle mostly due to SOD-1 up regulation.

The relationship between training status, blood pressure and uric acid in adults and elderly

Abstract Background Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index. Methods All participants (n = 123) performed the following tests: indirect maximal oxygen uptake (VO2max), AAHPERD Functional Fitness Battery Test to determine the general fitness functional index (GFFI), systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI) and blood sample collection to evaluate the total-cholesterol (CHOL), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), triglycerides (TG), uric acid (UA), nitrite (NO2) and thiobarbituric acid reactive substances (T-BARS). After the physical, hemodynamic and metabolic evaluations, all participants were allocated into three groups according to their GFFI: G1 (regular), G2 (good) and G3 (very good). Results Baseline blood pressure was higher in G1 when compared to G3 (+12% and +11%, for SBP and DBP, respectively, p<0.05) and the subjects who had higher values of BP also presented higher values of UA. Although UA was not different among GFFI groups, it presented a significant correlation with GFFI and VO2max. Also, nitrite concentration was elevated in G3 compared to G1 (140±29 μM vs 111± 29 μM, for G3 and G1, respectively, p<0.0001). As far as the lipid profile, participants in G3 presented better values of CHOL and TG when compared to those in G1. Conclusions Taking together the findings that subjects with higher BP had elevated values of UA and lower values of nitrite, it can be suggested that the relationship between blood pressure and the oxidative stress produced by acid uric may be mediated by training status.

Cessation of physical exercise changes metabolism and modifies the adipocyte cellularity of the periepididymal white adipose tissue in rats

All of the adaptations acquired through physical training are reversible with inactivity. Although significant reductions in maximal oxygen uptake (VO2max) can be observed within 2 to 4 wk of detraining, the consequences of detraining on the physiology of adipose tissue are poorly known. Our aim was therefore to investigate the effects of discontinuing training (physical detraining) on the metabolism and adipocyte cellularity of rat periepididymal (PE) adipose tissue. Male Wistar rats, aged 6 wk, were divided into three groups and studied for 12 wk under the following conditions: 1) trained (T) throughout the period; 2) detrained (D), trained during the first 8 wk and detrained during the remaining 4 wk; and 3) age-matched sedentary (S). Training consisted of treadmill running sessions (1 h/day, 5 days/wk, 50–60%VO2max). The PE adipocyte size analysis revealed significant differences between the groups. The adipocyte cross-sectional area (in µm2) was significantly larger in D than in the T and S groups (3,474 ± 68.8; 1,945.7 ± 45.6; 2,492.4 ± 49.08, respectively, P < 0.05). Compared with T, the isolated adipose cells (of the D rats) showed a 48% increase in the ability to perform lipogenesis (both basal and maximally insulin-stimulated) and isoproterenol-stimulated lipolysis. No changes were observed with respect to unstimulated lipolysis. A 15% reduction in the proportion of apoptotic adipocytes was observed in groups T and D compared with group S. The gene expression levels of adiponectin and PPAR-gamma were upregulated by factors of 3 and 2 in D vs. S, respectively. PREF-1 gene expression was 3-fold higher in T vs. S. From these results, we hypothesize that adipogenesis was stimulated in group D and accompanied by significant adipocyte hypertrophy and an increase in the lipogenic capacity of the adipocytes. The occurrence of apoptotic nuclei in PE fat cells was reduced in the D and T rats; these results raise the possibility that the adipose tissue changes after detraining are obesogenic.