Broiler walking ability and toe asymmetry under harsh rearing conditions

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

Protocols for hyperlactatemia induction in the lactate minimum test adapted to swimming rats

The lactate minimum test (LACmin) has been considered an important indicator of endurance exercise capacity and a single session protocol can predict the maximal steady state lactate (MLSS). The objective of this study was to determine the best swimming protocol to induce hyperlactatemia in order to assure the LACmin in rats (Rattus norvegicus), standardized to four different protocols (P) of lactate elevation. The protocols were PI: 6 min of intermittent jumping exercise in water (load of 50% of the body weight - bw); P2: two 13% bw load swimming bouts until exhaustion (thin); P3: one thin 13% bw load swimming bout; and P4: two 13% bw load swimming bouts (1st 30 s, 2nd to thin), separated by a 30 s interval. The incremental phase of LACmin beginning with initial loads of 4% bw, increased in 0.5% at each 5 min. Peak lactate concentration was collected after 5, 7 and 9 min (mmol L-1) and differed among the protocols P 1 (15.2 +/- 0.4, 14.9 +/- 0.7, 14.8 +/- 0.6) and P2 (14.0 +/- 0.4, 14.9 +/- 0.4, 15.5 +/- 0.5) compared to P3 (5.1 +/- 0.1, 5.6 +/- 0.3, 5.6 +/- 0.3) and P4 (4.7 +/- 0.2, 6.8 +/- 0.2, 7.1 +/- 0.2). The LACmin determination success rates were 58%, 55%, 80% and 91% in P1, P2, P3 and P4 protocols, respectively. The MLSS did not differ from LACmin in any protocol. The LACmin obtained from P4 protocol showed better assurance for the MLSS identification in most of the tested rats. (c) 2007 Elsevier B.V. All rights reserved.

The Lactate Minimum Test protocol provides valid measures of cycle ergometer VO2 peak

Aim. The aim of the present study was to investigate the validity of the Lactate Minimum Test (LMT) for the determination of peak VO2 on a cycle ergometer and to determine the submaximal oxygen uptake (VO2) and pulmonary ventilation (VE) responses in an incremental exercise test when it is preceded by high intensity exercise (i.e., during a LMT).Methods. Ten trained male athletes (triathletes and cyclists) performed 2 exercise tests in random order on an electromagnetic cycle ergometer: 1) Control Test (CT): an incremental test with an initial work rate of 100 W, and with 25 W increments at 3-min intervals, until voluntary exhaustion; 2) LMT: an incremental test identical to the CT, except that it was preceded by 2 supramaximal bouts of 30-sec (similar to120% VO(2)peak) with a 30-sec rest to induce lactic acidosis. This test started 8 min after the induction of acidosis.Results. There was no significant difference in peak VO2 (65.6+/-7.4 ml.kg(-1).min(-1); 63.8+/-7.5 ml.kg(-1).min(-1) to CT and LMT, respectively). However, the maximal power output (POmax) reached was significantly higher in CT (300.6+/-15.7 W) than in the LMT (283.2+/-16.0 W).VO2 and VE were significantly increased at initial power outputs in LMT.Conclusion. Although the LMT alters the submaximal physiological responses during the incremental phase (greater initial metabolic cost), this protocol is valid to evaluate peak VO2, although the POmax reached is also reduced.

Efeito da cadência de pedalada sobre as respostas metabólica e cardiovascular durante o exercício incremental e de carga constante em indivíduos ativos

The main purpose of this study was to analyze the effect of the pedaling cadence (500 × 100 rpm) on the heart rate (HR) and the blood lactate response during incremental and constant workload exercises in active individuals. Nine active male individuals (20.9 ± 2.9 years old; 73.9 ± 6.5 kg; 1.79 ± 0.9 m) were submitted to two incremental tests, and to 6-8 constant workload tests to determine the intensity corresponding to the maximal steady state lactate (MLSSintens) in both cadences. The maximal power (Pmax) attained during the incremental test, and the MLSSintens were significantly lower at 100 rpm (240.9 ± 12.6 W; 148.1 ± 154.W) compared to 50 rpm (263.9 ± 18.6 W; 186.1 ± 21.2 W), respectively. The HRmax did not change between cadences (50 rpm = 191.1 ± 8.8 bpm; 100 rpm = 192.6 ± 9.9 bpm). Regardless the cadence, the HRmax percentage (70, 80, 90, and 100%) determined the same lactate concentrations during the incremental test. However, when the intensity was expressed in Pmax percentage or in absolute power, the lactate and the HR values were always higher at highest cadences. The HR corresponding to MLSSintens was similar between cadences (50 rpm = 162.5 ± 9.1 bpm; 100 rpm = 160.4 ± 9.2 bpm). Based on these results, it can be conclude that regardless the cadence employed (50 × 100 rpm), the use of the HR to individualize the exercise intensity indicates similar blood lactate responses, and this relationship is also kept in the exercise of constant intensity performed at MLSSintens. On the other hand, the use of the Pmax percentages depend on the cadence used, indicating different physiological responses to a same percentage.

Effects of 12-week overground walking training at ventilatory threshold velocity in type 2 diabetic women

This study analyzed the effects of overground walking training at ventilatory threshold (VT) velocity on glycaemic control, body composition, physical fitness and lipid profile in DM2 women. Nineteen sedentary patients were randomly assigned to a control group (CG; n=10, 55.9±2.2 years) or a trained group (TG; n=9, 53.4±2.3 years). Both groups were subjected to anthropometric measures, a 12-h fasting blood sampling and a graded treadmill exercise test at baseline and after a 12-week period, during which TG followed a training program involving overground walking at VT velocity for 20-60min/session three times/week. Significant group×time interactions (P<0.05) in glycated hemoglobin (HbA1c), body mass, body mass index (BMI), peak oxygen uptake (VO 2peak) and exercise duration were observed as effects of training exercise, whereas intervention did not induced significant changes (P>0.05) in fasting blood glucose, submaximal fitness parameters and lipid profile. Our results suggest that overground walking training at VT velocity improves long term glycaemic control, body composition and exercise capacity, attesting for the relevance of this parameter as an effective strategy for the exercise intensity prescription in DM2 population. © 2011 Elsevier B.V.

Effects of fatigue induced by prolonged gait when walking on the elderly

Purpose. Fatigue has been pointed as a fall risk in the elderly; however, the effects of prolonged gait on neuromuscular recruitment and on its pattern remain unknown. The aim of this study was to evaluate the effects of prolonged gait on neuromuscular recruitment levels and spatial-temporal gait variables. Methods. Eight healthy older women (age: 72.63 ± 6.55 years) walked at their preferred walking speed for twenty minutes on a treadmill. The Root Mean Square (RMS) from the vastus-lateralis, femoral biceps, tibialis anterior and lateral gastrocnemius muscles were determined at the first and last minute of the test during the moments of Heel Strike (HS), Terminal Stance and Terminal Swing (TS). In addition, coactivation in the knee and ankle as well as the stride cadence and length were measured in the test. The two RMS data (taken at the first and last minute) were compared by means of a Student's t-test. Results. Twenty minutes of walking induced fatigue in the subjects, as observed through an increase in RMS, notably during the HS and TS. Coactivation was also influenced by the prolonged gait test. The only gait phase where a risk of falling was enhanced was the HS. Nonetheless, subjects developed strategies to maintain a safe motor pattern, which was evidenced by an increase in stride length and a decrease in stride cadence. Conclusion. Tests lasting just twenty minutes on a treadmill were enough to induce fatigue in older adults. However, the level of fatigue was not enough to present a danger or fall risk to elderly individuals.

Predição da potência aeróbia (VO 2máx) de crianças e adolescentes em teste incremental na esteira rolante

The maximal oxygen uptake (VO2max) is the maximal quantity of energy that can be produced by the aerobic metabolism in certain time unity. It can be determined direct or indirectly by predictive equations. The objective of this study was to make a specific predictive equation to determine the VO 2max from boys aged 10-16 years-old. Forty-two boys underwent a treadmill running ergospirometric test, with the initial velocity set at 9 km/h, until voluntary exhaustion. By the multiple linear regression was possible to develop the following equation for the indirect determination of the VO 2max: VO2max (ml/min) = -1574.06 + (141.38 x Vpeak) + (48.34 * Body mass), with standard error of estimate = 191.5 ml/min (4.10 ml/kg/min) and coefficient of determination = 0.934. We suggest that this formula is appropriate to predict VO2max for this population.

Influência da aptidão aeróbia no running anaerobic sprint test (RAST)

The aim of this study was to investigate the possible influence of different levels of aerobic fitness (VO2MAX) on the parameters of the running anaerobic sprint test (RAST). Thirty-eight subjects (Age = 18.1 ± 2.5 years, Height = 173 ± 1 cm and Body mass = 65.1 ± 6.5 kg) were classified into two groups, low and high aerobic fitness (LAF: n = 22 and HAF: n = 16). The VO2MAX was determined by an incremental exercise performed until exhaustion. The RAST was composed of six maximal efforts of 35m separated by 10s passive recovery. The VO2MAX was significantly different between groups (LAF = 51.7 ± 1.9 mL.kg -1.min-1; HAF = 58.6 ± 3.1 mL.kg -1.min-1). The mean power (MP) was significantly higher in the LAF (552.7 ± 132.1 W) in relation to the HAF group (463.6 ± 132.8 W). The impulse (ImP) was significantly correlated with the VO 2MAX in HAF. It can be concluded that there is an indication that the aerobic metabolism exerts an influence on the completion of RAST.

Comparison between the six-minute walk test and the six-minute step test in post stroke patients

Background: The Stroke remains one of the major chronic diseases worldwide, and is considered a major cause of disability, which results not only in persistent neurological deficits, but also in the high physical deconditioning, nevertheless there are not many forms of assessing functional capacity in this population. We aimed to investigate the feasibility of the Six Minute Walk Teste and the Six-Minute Step Test (6MST) in post-stroke patients and compare the behavior of physiological variables during the 6MST and the Six-Minute Walk Test (6MWT), by correlating the functional performance obtained in both tests. Method. The 6MWT was carried out according to the American Thoracic Society (ATS) and the 6MST was performed in six minutes in order to compare it to the 6MWT in a 20 cm step. Was included post-stroke individuals able to walk without aid. All of them did the 6MWT and the 6MST. Results: 12 patients participated in the study. There was no statistical difference in the parameters analyzed when tests were compared. There was poor correlation between the functional performance in both tests. Conclusion: The 6MWT and the 6MST is feasible for post-stroke patients and physiological responses are equal during the performance of both tests. However, there was no correlation with respect to functional performance, which was assessed by the distance walked in the 6MWT and by the number of steps climbed in the 6MST. © 2013 da Silva et al.; licensee BioMed Central Ltd.

Test-retest reliability of a 3-min isokinetic all-out test using two different cadences

Objectives: To investigate the test-retest reliability of mechanical parameters derived from a 3-min isokinetic all-out test, performed at 60 and 100 rpm. Reliability and validity of the peak oxygen uptake derived from 3-min isokinetic all-out test were also tested. Design: 14 healthy male subjects completed an incremental ramp testing and four randomized 3-min isokinetic all-out test (two at 60 rpm and two at 100 rpm). Methods: The absolute and relative reliability of the following parameters were analyzed: peak power, mean power, end power, fatigue index, work performed above end power and peak oxygen uptake. Results: No difference was found between each two sets of data, although there were between-cadence differences for peak power, mean power, end power, and fatigue index. Higher intra-class correlation (ICC) and lower coefficient of variation (CV) were found for end power (ICC = 0.91 and 0.95; CV = 5.6 and 5.7%) and mean power (ICC = 0.97 and 0.98; CV = 2.4 and 3.1%), than for peak power (ICC = 0.81 and 0.84; CV = 8.7 and 10%) and work performed above end power (ICC = 0.79 and 0.84; CV = 7.9 and 10.6%; values reported for 60 rpm and 100 rpm, respectively). High reliability scores were also observed for peak oxygen uptake at both cadences (60 rpm, CV = 3.2%; 100 rpm, CV = 2.3%,) with no difference with the incremental ramp testing peak oxygen uptake. Conclusions: The power profile and peak oxygen uptake of a 3-min isokinetic all-out test are both highly reliable, whether the test is performed at 60 or 100 rpm. Besides, peak oxygen uptake and work performed above end power were not affected by the change in cadence while peak power, mean power, end power, and fatigue index were. © 2013.

Caracterização do perfil de atividade física na vida diária de pacientes portadores de DPOC do Brasil e comparação com pacientes da Áustria

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise de parâmetros eletromiográficos e cinemáticos durante teste incremental de corrida: Priscila de Brito Silva. -

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Treinamento de cavalos de enduro FEI*: abordagem fisiológica

Pós-graduação em Medicina Veterinária - FCAV

Analysis of cardiopulmonary and metabolic variables measured during laboratory and sport-specific incremental tests for table tennis performance prediction

Purpose. - The purposes of this study were: i) to compare the physiological responses measured during a specific table tennis incremental test with the physiological responses measured during cycling, arm cranking, and treadmill running tests; and ii) to verify the accuracy of table tennis performance prediction based on the physiological responses from these tests.Methods. - Eleven national level male table tennis players participated in the study and undertook incremental tests using ergometers. Table tennis performance was defined as the ranking obtained during a simulated tournament between the participants.Results. - In general, peak values for physiological variables (e.g., (V) over dotO(2PEAK) and [La]PEAK) were significantly lower (P < 0.05) in the specific test (e.g., (V) over dotO(2PEAK) = 39.9 +/- 1.5 ml.kg(-1) per minute and [La]PEAK = 6.4 +/- 0.5 mmol.L-1) than during cycling (e.g., (V) over dotO(2PEAK) = 41.3 +/- 1.4 ml.kg(-1) per minute and [La]PEAK = 10.2 +/- 0.7 mmol.L-1) or running (e.g., (V) over dotO(2PEAK) = 43.9 +/- 1.5 ml.kg(-1) per minute and [La]PEAK = 10.0 +/- 0.7 mmol.L-1), but higher than during arm cranking (e.g., (V) over dotO(2PEAK) = 26.6 +/- 1.6 ml.kg(-1) per minute and [La]PEAK = 8.9 +/- 0.6 mmol.L-1). At respiratory compensation point intensity (RCP), only the variables measured on arm cranking were lower (P < 0.05) than on the other ergometers. Stepwise multiple regression analysis showed significant correlation between table tennis performance and lactate concentration ([La]) and also rate of perceived effort (RPE) at RCP during cycling (r = 0.89; P < 0.05).Conclusion. - In conclusion, the significant differences obtained between the specific and laboratory ergometers demonstrate the need to use a specific test to measure physiological parameters in table tennis and the physiological parameters measured, independent of the ergometer used, are unable to predict table tennis performance. (C) 2013 Elsevier Masson SAS. All rights reserved.

Reliability of peak running speeds obtained from different incremental treadmill protocols

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)