[show abstract][hide abstract] ABSTRACT: There has been little research regarding cardiorespiratory responses during submaximal exercise at the maximal lactate steady state intensity (MLSS int) until exhaus-tion. The objective of this study was to investigate the responses of oxygen consumption (VO 2), heart rate (HR) and oxygen pulse (O 2 pulse) during exercise to exhaustion at MLSS int , and to compare energy expenditure (EE) estimated by VO 2 and HR. Twelve trained athletes followed an incremental protocol on a cycle ergometer to determine maximal and submaximal parameters of aerobic metabolism. On subsequent occasions they performed 2 to 4 30-minute tests with constant load to identify MLSS int . Finally, they underwent a test to exhaustion at MLSS int . Cardiorespiratory parameters were measured continuously during all tests. During the test to exhaustion, physiological responses were compared for six points in time calculated as percentages of the time to exhaustion (TTE). Mean TTE was 55.1±10.2 min. Oxygen pulse presented significant reduction over time, decreasing to a value 9% lower than baseline at the exhaustion point. This fact was the result of increases in HR over time that was disproportional to the increase in VO 2 , resulting in significant differences between EE estimates. Therefore, there appears to be a gradual loss of cardiorespiratory efficiency during exercise to exhaustion at MLSS int that is shown by the reduction in O 2 pulse. The direct relationship between VO 2 and HR with workload presents variations over the course of exercise, leading to errors when EE is estimated using HR.
Revista Brasileira de Cineantropometria e Desempenho Humano. 02/2014; 16(2):212-222.
[show abstract][hide abstract] ABSTRACT: O objetivo deste estudo foi comparar a potência muscular de membros inferiores a partir do
counter movement jump (CMJ) em diferentes momentos da temporada (final da temporada, inicio e final
da pré-temporada seguinte) em jogadores de futebol e, além disso, foram estudados dados de composição
corporal nos três momentos analisados. Participaram do estudo 17 atletas de futebol com idade de 17,8 ±
1,1 anos da categoria juniores de um clube de futebol profissional participante da série A do Campeonato
Brasileiro. O percentual de gordura corporal estimado no início da pré-temporada foi significativamente
superior ao mensurado no final da temporada anterior (p<0,05). O desempenho no salto vertical
apresentou uma queda significativa (5,8%, p<0,05) apenas após a realização da pré-temporada quando
analisada a variável altura. Por outro lado, a potência muscular normalizada pelo peso corporal apresentou
manutenção nos três momentos analisados, indicando que o desempenho no CMJ é uma variável que não
apresenta alteração após um período curto (4 semanas) sem treinamento formal e que a maior ênfase no
treinamento aeróbio na pré-temporada pode ter contribuído para reduzir os níveis de potência muscular e a
altura atingida num salto vertical.
[show abstract][hide abstract] ABSTRACT: Abstract The purpose of the present investigation was to identify muscle damage, inflammatory response and oxidative stress blood markers in athletes undertaking the ultra-endurance MultiSport Brazil race. Eleven well-trained male athletes (34.3 ± 3.1 years, 74.0 ± 7.6 kg; 172.2 ± 5.1 cm) participated in the study and performed the race, which consisted of about 90 km of alternating off-road running, mountain biking and kayaking. Twelve hours before and up to 15 minutes after the race a 10 mL blood sample was drawn in order to measure the following parameters: lactate dehydrogenase and creatine kinase activities, lipid peroxidation, catalase activity, protein carbonylation, respiratory chain complexes I, II and IV activities, oxygen consumption and neopterin concentrations. After the race, plasma lactate dehydrogenase and creatine kinase activities were significantly increased. Erythrocyte TBA-RS levels and plasma protein carbonylation were markedly augmented in post-race samples. Additionally, mitochondrial complex II activity and oxygen consumption in post-race platelet-rich plasma were also increased. These altered biochemical parameters were accompanied by increased plasma neopterin levels. The ultra-endurance event provoked systemic inflammation (increased neopterin) accompanied by marked oxidative stress, likely by increasing oxidative metabolism (increased oxidative mitochondrial function). This might be advantageous during prolonged exercise, mainly for efficient substrate oxidation at the mitochondrial level, even when tissue damage is induced.
Journal of Sports Sciences 10/2013; · 2.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the test-retest reliability of mechanical parameters derived from a 3-min isokinetic all-out test, performed at 60 and 100rpm. Reliability and validity of the peak oxygen uptake derived from 3-min isokinetic all-out test were also tested.
14 healthy male subjects completed an incremental ramp testing and four randomized 3-min isokinetic all-out test (two at 60rpm and two at 100rpm).
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.
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 60rpm and 100rpm, respectively). High reliability scores were also observed for peak oxygen uptake at both cadences (60rpm, CV=3.2%; 100rpm, CV=2.3%,) with no difference with the incremental ramp testing peak oxygen uptake.
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 100rpm. 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.
Journal of science and medicine in sport / Sports Medicine Australia. 09/2013;
[show abstract][hide abstract] ABSTRACT: The aim of the present study was to compare physiological
responses derived from an incremental progressive field test
with a constant speed test i.e. intermittent versus continuous
protocol. Two progressive maximum tests (Carminatti`s test (TCAR)
and the Vameval test (T-VAM)), characterized by
increasing speed were used. T-CAR is an intermittent
incremental test, performed as shuttle runs; while T-VAM is a
continuous incremental test performed on an athletic track.
Eighteen physically active, healthy young subjects (21.9 ± 2.0
years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat),
volunteered for this study. Subjects performed four different
maximum test sessions conducted in the field: two incremental
tests and two time to exhaustion tests (TTE) at peak test
velocities (PV). No significant differences were found for PV
(T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h-1) and maximal
HR (T-CAR = 195 ± 11; T-VAM = 194 ± 14 bpm). During
TTE, there were no significant differences for HR (TTET-CAR
and TTET-VAM = 192 ± 12 bpm). However, there was a
significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84,
TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The
blood lactate concentration measured at the end of the TTE tests,
showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs.
TTET-VAM = 12.9 ± 2.4 mmol·l-1). Based on the present findings,
it is suggested that the maximal variables derived from T-CAR
and T-VAM can be interchangeable in the design of training
Journal of sports science & medicine 03/2013; 13(1):165-170. · 0.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of the study was to analyze the relationships among physiological and neuromuscular indices with the 200- and 400-m sprint running performance. Fourteen male sprinters performed the following tests: determination of 200- (P200) and 400-m (P400) running performance; determination of VO2max and the velocity associated at VO2max; squat jump (SJ) and countermovement jump (CMJ); and maximal accumulated oxygen deficit (MAOD). Significant correlations were observed between SJ (r = -0.53), CMJ (r = -0.69), and MAOD (r = -0.65) with P200. Countermovement jump (CMJ) and MAOD explained 70% of the P200. The MAOD was the only variable to correlate significantly with P400 (r = -0.56); VO2max and CMJ were also selected in the regression together and explained 79% of P400. The indicators of muscular power and anaerobic capacity are capable of explaining P200. In the 400 m, the performance was determined by indices of anaerobic capacity, in conjunction with the athletes' aerobic and muscular power.
Research in Sports Medicine An International Journal 02/2013; 21(2):124-35.
[show abstract][hide abstract] ABSTRACT: OBJECTIVE: The aim of the present study was to characterize the neuromuscular, biochemical, and endocrinal responses from a running to exhaustion mode at the maximal lactate steady state intensity during continuous and intermittent protocols. DESIGN: Pre-post test measures. METHODS: Twelve athletes performed an incremental treadmill test, several constant speed tests to determine the maximal lactate steady state at continuous and intermittent (5:1 ratio) models and two randomized tests until exhaustion at such intensities. Knee extension torque and blood sampling were collected before and immediately after the time to exhaustion tests. RESULTS: The results showed a significant decrement (∼15%) in torque production after time to exhaustion tests for both exercise models. In addition to neuromuscular impairment, an acute increase of 65% and 38% was observed creatine kinase, during continuous and intermittent running, respectively. Regarding hormonal responses when compared to baseline measurements, cortisol increased by 132% and 121% in the continuous and intermittent protocols, respectively. No correlation was found between biochemical, endocrinal and the neuromuscular variables. CONCLUSION: The present findings showed that running until exhaustion performed at maximal lactate steady state, significantly impaired muscle strength and increased hormonal and muscle damage markers in two different protocols (i.e. continuous and intermittent) amongst trained runners.
Journal of Science and Medicine in Sport 02/2013; · 2.90 Impact Factor
[show abstract][hide abstract] ABSTRACT: Objectifs
Le but de cette étude est de déterminer les réponses physiologiques et le temps d’épuisement, à la puissance critique et à 5 % au-dessus de la puissance critique pour des cyclistes entraînés.
Équipement et méthode
Onze cyclistes masculins ont complété un test progressif, trois tests à charge constante jusqu’à épuisement pour déterminer les puissances critiques et enfin deux tests jusqu’à épuisement à la puissance critique et puissance critique plus 5 %.
La modélisation de la relation entre puissance inverse et le temps a fourni une puissance critique de 295 ± 39 W. Le temps jusqu’à l’épuisement à la puissance critique a été considérablement plus élevé que 5 % au-dessus (22,9 ± 7,5 min versus 13,3 ± 5,8 min). La consommation d’oxygène, la ventilation pulmonaire et le lactate sanguin obtenu à la fin de l’essai de l’épuisement à la puissance critique +5 % n’ont pas été considérablement différents des variables maximales. Néanmoins, les valeurs physiologiques finales pendant les puissances critiques test ont été considérablement inférieures comparativement au test progressif.
Les informations appuient l’idée que la puissance critique des cyclistes entraînés est l’index physiologique qu’estime la limite entre le domaine d’exercice lourd et sévère. Donc, quand les cyclistes sont entraînés à une puissance 5 % plus élevée que la puissance critique, la consommation maximale d’oxygène a été atteinte à la fin de l’exercice.
[show abstract][hide abstract] ABSTRACT: Objectives. — The aim of this study was to determine the physiological responses and time to
exhaustion, at critical power and 5% above, in trained cyclists.
Equipments and methods. — Eleven male cyclists completed an incremental test, three constant
work rate tests to exhaustion to determine critical power (CP), and finally two tests until
exhaustion at CP and CP plus 5%.
Results. — The modeling of the power-inverse time relationship provided a mean critical power
39 W. Time to exhaustion at critical power was significantly higher than 5% above
7.5 min versus 13.3
5.8 min). Oxygen uptake, pulmonary ventilation, and blood lactate
obtained at the end of the CP plus 5% exhaustion trial were not significantly different from the
maximal variables. However, the physiological end values during the CP test were significantly
lower compared to the incremental test.
Conclusions. — These data support the idea that CP in trained cyclists is the physiological index
that estimates the boundary between heavy to severe exercise domains. Thus, when cyclists
exercised at a power output 5% higher than CP, the VO2max was reached at the end of exercise.
[show abstract][hide abstract] ABSTRACT: The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR) and the Vameval test (T-VAM)), characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat), volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE) at peak test velocities (PV). No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h(-1)) and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm). During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm). However, there was a significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l(-1)). Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs. Key pointsT-CAR is an intermittent shuttle run test that predicts the maximal aerobic speed with accuracy, hence, test results could be interchangeable with continuous straight-line tests.T-CAR provides valid field data for evaluating aerobic fitness.In comparison with T-VAM, T-CAR may be a more favourable way to prescribe intermittent training using a shuttle-running protocol.
Journal of sports science & medicine 01/2013; 12(1):165-70. · 0.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: Introdução Vários estudos têm procurado determinar os índices fisiológicos capazes de predizer a performance aeróbia e que, também, possam ser utilizados como referência para prescrição e controle dos efeitos do treinamento (BRANDON, BOILEAU, 1987; BRANDON, 1995; DENADAI, 1996; DENADAI; ORTIZ; MELLO, 2004). Tradicionalmente, os índices aeróbios mais estudados para a predição da performance durante as corridas de endurance são o consumo máximo de oxigênio (VO 2 max), a velocidade correspondente ao VO 2 max (vVO 2 max), o tempo de exaustão na vVO 2 max e a economia de corrida (EC) (DENADAI, 1996; DENADAI; ORTIZ; MELLO, 2004; BILLAT et al., 1999; DENADAI, 1999). Embora o VO 2 max seja o parâmetro fisiológico que melhor expressa a aptidão cardiorrespiratória do indivíduo (BASSETT; HOWLEY, 2000), o mesmo apresenta um baixo poder discriminatório da performance em um grupo homogêneo de corredores (DENADAI; ORTIZ: MELLO, 2004). Por outro lado, a velocidade correspondente ao VO 2 max (vVO 2 max) é um índice determinante para a predição de performance em provas de média e longa duração (NOAKES; MYBURGH; SCHALL, 1990). Sobretudo, porque este índice Motriz, Rio Claro, v.18 n.4, p.690-698, out./dez. 2012 Artigo Original Índices fisiológicos associados com a performance aeróbia de corredores nas distâncias de 1,5 km, 3 km e 5 km Resumo: O objetivo do estudo foi analisar a associação entre os índices fisiológicos de potência aeróbia e capacidade aeróbia performance nas distâncias de 1,5 km, 3 km e 5 km. Nove corredores de endurance realizaram os seguintes protocolos: a) teste para determinação do VO 2 max, vVO 2 max e OBLA; b) 2-5 testes em dias alternados de 30 min com velocidade constante para determinar a vMLSS e c) determinação da performances. Foram empregadas correlação linear de Pearson ou Spearman e regressão múltipla para determinar as relações entre os índices e a performance nas corridas. Observou-se uma correlação significante somente da vVO 2 max com o tempo nas distâncias de 1,5 km (r = -0,78) e 3 km (r = -0,81). Dessa forma, pode-se sugerir a inclusão de sessões de treinamento em intensidade próxima ou superior à vVO 2 max na periodização semanal dos corredores. Com base nesses achados, foi possível concluir que a predição da performance por meio de índices de potência aeróbia e da capacidade aeróbia depende da distância e duração da prova. Palavras-chave: Corredores. Lactato. Índices fisiológicos. Performance. Physiological indices associated with aerobic performance in the distances of 1,5 km, 3 km and 5 km
Motriz. Revista de Educação Física 10/2012; 18(4):690-698. · 0.09 Impact Factor
[show abstract][hide abstract] ABSTRACT: The maximal lactate steady state (MLSS) represents a submaximal intensity that may be important in prescribing both continuous and interval endurance training. This study compared time to exhaustion (TTE) at MLSS in continuous and intermittent (i.e., with pauses) exercise, investigating whether physiological variables differ between these exercise modes. Fourteen trained male cyclists volunteered for this investigation and performed an incremental test, several 30-min tests to determine two MLSS intensities (continuous and discontinuous protocol), and two randomized tests until exhaustion at MLSS intensities on a cycle ergometer. The intermittent or discontinuous protocol was performed using 5 min of cycling, with an interval of 1 min of passive rest. TTE at intermittent MLSS was 24% longer than TTE at continuous exercise (67.8 ± 14.3 min vs. 54.7 ± 10.9 min; p < 0.05; effect sizes = 1.04), even though the absolute power output of intermittent MLSS was higher than continuous (268 ± 29 W vs. 251 ± 29 W; p < 0.05). Additionally, the total mechanical work done was significantly lower at continuous exercise than at intermittent exercise. Likewise, regarding cardiorespiratory and metabolic variables, we observed greater responses during intermittent exercise than during continuous exercise at MLSS. Thus, for endurance training prescription, this is an important finding to apply in extensive interval sessions at MLSS. This result suggests that interval sessions at discontinuous MLSS should be used instead of continuous MLSS, as discontinuous MLSS allows for a larger amount of total work during the exhaustion trial.
Applied Physiology Nutrition and Metabolism 08/2012; · 2.01 Impact Factor
[show abstract][hide abstract] ABSTRACT: The aim of this study was to compare anaerobic threshold (AT) as determined by four different methods with maximal lactate steady state (MLSS) in endurance run-ners. Nine moderately trained runners performed the following tests on different days: a maximal incremental exercise test to determine maximal oxygen uptake (VO 2 max), velocity at VO 2 max (vVO 2 max), and blood lactate response; and two to five 30-min constant load tests to determine MLSS. Based on the incremental test, four methods of AT determination were used: AT1 – velocity at 3.5 mmol.L -1 blood lactate; AT2 – velocity corresponding to the minimum lactate-velocity equivalent plus 1.5 mmol.L -1 ; AT3 – ve-locity at Dmax; and AT4 – velocity before the second consecutive blood lactate increase greater than 0.5 mmol.L -1 . There were no significant differences between MLSS and AT as determined by four different methods. However, the Bland-Altman analysis showed the extent of disagreement between variables when the subjects were analyzed individually. MLSS was significantly correlated with AT1 (r=0.68; p=0.04) and AT2 (r=0.79; p=0.01). Thus, although no significant differences were found between AT methods and MLSS, one should be cautious about using these methods interchangeably. Resumo – O objetivo deste estudo foi determinar e comparar o limiar anaeróbio (LAn) obtido por quatro diferentes métodos com o máximo estado estável de lactato (MLSS) em corredores de endurance. Nove corredores moderadamente treinados realizaram, em diferentes dias, os seguintes testes: um teste incremental máximo para determinação do consumo máximo de oxigênio (VO 2 max), velocidade correspondente ao VO 2 max (vVO 2 max) e resposta do lactato sanguíneo e; dois a cinco testes de intensidade constante, com 30 min de duração, para determinação do MLSS. A partir do teste incremental, foram utilizados quatro métodos de determinação do LAn: LAn1 -velocidade correspondente a [La] fixa de 3,5 mmol.L -1 ; LAn2 -velocidade referente a [La] do menor equivalente [La]-velocidade somado com 1,5 mmol.L -1 ; LAn3 -velocidade correspondente ao Dmax; LAn4 -velocidade anterior ao segundo incremento consecutivo de [La] maior que 0,5 mmol.L -1 . Não existiram diferenças significativas entre o MLSS e o LAn determinado pelos quatro métodos estudados. Entretanto, a análise de Bland-Altman expressou a extensão da discordância entre as variáveis quando os sujeitos foram analisados individualmente. Houve correlações significativas entre MLSS e LAn1 (r = 0,68; p = 0,04) e entre MLSS e o LAn2 (r = 0,79; p = 0,01). Assim, apesar de não haver diferença significativa entre os métodos de determinação do LAn com o MLSS, deve-se ter cautela para utilizá-los de forma intercambiável. Palavras-chave: Corrida; Exercício aeróbio; Lactato sanguíneo.
Brazilian Journal of Kinantropometry and Human Performance. 05/2012; 14(3):264-275.
[show abstract][hide abstract] ABSTRACT: The lactate anaerobic threshold (AT) determined during an incremental test has been used generally to estimate the maximal lactate steady-state intensity (MLSSint) in several sports. Furthermore, this index could be useful to predict the time-trial cycling performance and also to prescribe training intensity to enhance aerobic capacity. The aim of this study was to compare three different ATestimations with actual MLSSint in trained cyclists. Fourteen trained cyclists participated in this study. They had previously performed a maximal incremental cycling test (35 W increments each 3 min) in a laboratory
followed by three to five visits to measure the MLSSint (30-min tests). Blood lactate concentration ([La]), oxygen uptake (V˙O2), and heart rate (HR) were measured during all tests. Based on the incremental test, we calculated three ATs using different proposed methods: AT1-intensity corresponds to fixed [La]; AT2-minimum equivalent of the blood lactate-power output relationship plus 1.5 mmol�L�1; AT3-power output of the stage antecedent to the second lactate increase of at least 0.5 mmol�L�1 above the previous values, where the second increase was greater than the first. The MLSSint was determined for each participant as the highest power output that could be maintained with [La] fluctuating less than 1 mmol�L�1 during the final 20 min of the steady-state tests. ANOVA with repeated measures was used to compare physiological variables in the different methods. The relationship between the MLSSint and the power output of AT1, AT2,
and AT3 was analysed using Pearson product-moment correlation coefficients. In addition, we calculated the bias and limits of agreement between the three different methods with actual MLSSint. The mean9s values of power output related to MLSSint, AT1, AT2, and AT3 were 247933 W, 258939 W, 248935 W, and 230936 W, respectively. The results showed that AT3 underestimated (PB0.05) the MLSSint for most of the participants and provided lower mean values compared with AT1 and AT2. Furthermore, AT2 seems to be more accurate to estimate MLSSint than other methods here verified when we analysed the mean values, correlation coefficient (r�0.94), and Bland-Altman limits of agreement (99.5%). The AT1 also provided good prediction values, although it presented with a trend to overestimate MLSSint. Therefore, considering the
methods analysed in the current study and the importance of this submaximal aerobic index to flat time-trials and prolonged uphill cycling performance, the AT2 method could be used with good accuracy by coaches and athletes.
European Journal of Sport Science 03/2012; 12(2):161-167. · 1.15 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of the present study was to compare the critical speed (CS) with the speed at the maximal lactate steady state (vMLSS) determined by a continuous and an intermittent model in trained runners. Eight male endurance runners (30.3 ± 10.6 years; 65.0 ± 8.5 kg; 1.73 ± 0.6 m; 11.3 ± 4.0% body fat) volunteered for this investigation and performed an incremental treadmill test, as well as 2-5 30-min constant speed tests to determine the MLSS continuous and MLSS intermittent (5 min of running, interspaced by 1 min of passive rest). The CS was determined by 2 maximal running efforts of 1500 and 3000 m performed on a 400 m running track. The CS was calculated as the slope of the linear regression of distance versus time. Statistical analysis revealed no significant difference between CS and MLSS determined by intermittent running (15.2 ± 1.0 km·h(-1) vs. 15.3 ± 0.7 km·h(-1), respectively), however, both were significantly higher than continuous MLSS (14.4 ± 0.6 km·h(-1)). There was also a significant correlation between CS and MLSS intermittent (r = 0.84, p = 0.008). On the basis of the present results, we conclude that for practical reasons (low cost, non-invasive) the CS is an interesting and alternative method to prescribe endurance interval training at maximal lactate steady state intensity, in preference to a continuous protocol.
Journal of sports science & medicine 01/2012; 11(1):89-94. · 0.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test-retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h(-1) was increased by 1.2 km · h(-1) every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO(2max) (v-VO(2max)). Peak running velocity in Carminatti's test was strongly correlated with v-VO(2max) (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = -0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players.
Journal of Sports Sciences 11/2011; 29(15):1621-8. · 2.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: The aim of this study was to verify the validity of a new progressive distance and fixed time test (Carminatti's test [TCAR]) in estimating the main physiological indices of aerobic fitness in team-sport players. Thirty professional national level team-sport players (n = 12 futsal players and 18 soccer players) volunteered to participate in this study. The subjects performed the TCAR and a laboratory incremental treadmill test (ITT). The TCAR required subjects to complete repeated sets of 5 × 12-second shuttle-running bouts at progressive speed until volitional exhaustion. Each 12-second bout and series were separated by a 6- and 90-second recovery periods, respectively. The initial distance was set at 15 m and was progressively increased by 1 m each set. The ITT commenced at a velocity of 9.0 km·h(-1) and was increased by 1.2 km·h(-1) each 3 minutes until volitional exhaustion. Peak TCAR running velocity resulted not significantly (p > 0.05) different from speed at VO2max (vVO2max) during ITT. Peak TCAR running velocity was significantly correlated (p < 0.01) with vVO2max (r = 0.55) and VO2max (r = 0.51). No significant differences were found (p > 0.05) among the mean values of velocity and heart rate at the anaerobic threshold, estimated in the TCAR test and measured in the ITT. In light of this study results, the TCAR can be considered as a viable field test to estimate aerobic power and capacity in team-sports players. The limited devices and space required by TCAR warrant consideration for those strength and conditioning professionals who deal with team sports.
The Journal of Strength and Conditioning Research 11/2011; 25(11):3099-106. · 1.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: Here, we established a program of low-intensity aerobic exercise and compared the effects of exercise preoperative, postoperative, and a combination of both pre- and postoperative protocols on recovery from sciatic nerve crush injury in mice using behavioral, biochemical, and morphological assays. Sciatic nerve crush was performed in adult male mice. The animals were submitted to preoperative (for 2 weeks), postoperative (for 2 weeks), and a combination of preoperative-postoperative (for 4 weeks) training protocols. During the training period, functional recovery was monitored using the Sciatic Functional Index, the Sciatic Static Index, and mechanical and cold hypersensitivity analyses. Morphological and biochemical alterations were analyzed on the 14th day post-crushing. The functional recovery values of all of the exercised groups were significantly better than the nonexercised group. Biochemically, all of the exercise groups showed a reduction in the increase of interleukin-1β (IL-1β) in the sciatic nerve and in the IL-1β and interleukin-6 receptor (IL-6R) levels in the spinal cord. However, the levels of tumor necrosis factor alpha (TNF-α) decreased only in the postoperative group and in the combination exercise protocols. In the morphological analysis, the combination exercise subjects presented an increase in fiber and axon diameter, in the myelination degree and in the number of myelinated fibers. The present study showed that pre- and postoperative exercise achieved values for functional and morphological sciatic nerve regeneration that were significantly better than either the preoperative or postoperative protocols. This experimental study suggests that physical exercise can restore motor and nerve function to a substantial degree when performed using a prophylactic and therapeutic approach.
[show abstract][hide abstract] ABSTRACT: Patients suffering from depression frequently display hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) resulting in elevated cortisol levels. One main symptom of this condition is anhedonia. There is evidence that exercise training can be used as a rehabilitative intervention in the treatment of depressive disorders. In this scenario, the aim of the present study was to assess the effect of an aerobic exercise training protocol on the depressive-like behavior, anhedonia, induced by repeated dexamethasone administration. The study was carried out on adult male Wistar rats randomly divided into four groups: the "control group" (C), "exercise group" (E), "dexamethasone group" (D) and the "dexamethasone plus exercise group" (DE). The exercise training consisted of swimming (1 h/d, 5 d/wk) for 3 weeks, with an overload of 5% of the rat body weight. Every day rats were injected with either dexamethasone (D/DE) or saline solution (C/E). Proper positive controls, using fluoxetine, were run in parallel. Decreased blood corticosterone levels, reduced adrenal cholesterol synthesis and adrenal weight (HPA disruption), reduced preference for sucrose consumption and increased immobility time (depressive-like behavior), marked hippocampal DNA oxidation, increased IL-10 and total brain-derived neurotrophic factor (BDNF; pro-plus mature-forms) and a severe loss of body mass characterized the dexamethasone-treated animals. Besides increasing testosterone blood concentrations, the swim training protected depressive rats from the anhedonic state, following the same profile as fluoxetine, and also from the dexamethasone-induced impaired neurochemistry. The data indicate that physical exercise could be a useful tool in preventing and treating depressive disorders.