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The present study aimed to compare maximal oxygen uptake of a step incremental test with time to exhaustion verification tests (TLIM) performed on the same or different day. Nineteen recreationally trained cyclists (age: 23 ± 2.7 years; maximal oxygen uptake: 48.0 ± 5.8 mL·kg-1·min-1) performed 3 maximal tests as follows: (i) same day: an incremental test with 3-min stages followed by a TLIM at 100% of peak power output of the incremental test (TLIM-SAME) interspaced by 15 min; and (ii) different day: a TLIM at 100% of peak power output of the incremental test (TLIM-DIFF). The maximal oxygen uptake was determined for the 3 tests. The maximal oxygen uptake was not different among the tests (incremental: 3.83 ± 0.41; TLIM-SAME: 3.72 ± 0.42; TLIM-DIFF: 3.75 ± 0.41 L·min-1; P = 0.951). Seven subjects presented a variability greater than ±3% in both verification tests compared with the incremental test. The same-day verification test decreased the exercise tolerance (240 ± 38 vs. 310 ± 36 s) compared with TLIM-DIFF (P < 0.05). In conclusion, the incremental protocol is capable of measuring maximal oxygen uptake because similar values were observed in comparison with verification tests. Although the need for the verification phase is questionable, the additional tests are useful to evaluate individual variability. Novelty Step incremental test is capable of measuring maximal oxygen uptake with similar values during TLIM on the same or different day. Although the necessity of the verification phase is questionable, it can allow the determination of variability in maximal oxygen uptake.

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To investigate the presence of a relative age effect (RAE) and the influence of birth quarters (BQ), semesters (S) as well as skeletal maturation on anthropometric characteristics and aerobic peak speed (PST-CAR) in youth male soccer players. Methods: One hundred players were recruited to participate in this study. Players were allocated into 4 BQ's and 2 S. Skeletal maturity status was assessed using the Fels method. Assessments for players included determination of body size and composition and PST-CAR. Results: Overall, more players were born in BQ1 (38 %) and S1 (75%). The likelihood of players born in BQ1 and BQ2 being selected was 3.61 to 4.96 times higher than players in BQ3 and BQ4. Players in BQ4 maturing earlier were biologically older than their peers in BQ1. The players in BQ3 and S2 displayed higher PST-CAR compared with players in BQ2 and S1, respectively. However, players of contrasting skeletal maturity status did not differ in aerobic performance. Conclusion: Our findings indicate that coaches and talent scouts are systematically retaining average and early maturing players born in S1 and excluding late maturing players born in BQ4. However, aerobic performance appeared to be dependent on the relative age, but independent of skeletal maturation during puberty.(AU)

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The aim of this study was to investigate the physiological responses during the time limit at the intensity of the peak velocity of the Carminatti's test (T-CAR). Ten professional futsal players (age, 27.4 ± 5.8 years, body mass, 78.8 ± 8.5 kg, body height, 175.8 ± 6.8 cm, body fat mass, 14.1 ± 2.6%) took part in the study. The players performed three tests, with an interval of at least 48 hours, as follows: the T-CAR to determine the peak velocity and the maximal heart rate; an incremental treadmill protocol to determine the maximal physiological responses; and a time limit running test at the peak velocity reached in the T-CAR. During the last two tests, a portable gas analyzer was used for direct measurement of cardiorespiratory variables. It was shown that the peak velocity was not significantly different from the maximal aerobic speed achieved in the laboratory (p = 0.213). All athletes reached their maximum oxygen uptake during the time limit test. The maximum oxygen uptake achieved during the time limit test was not different from that observed in the laboratory condition (51.1 ± 4.7 vs. 49.6 ± 4.7 ml·kg-1·min-1, respectively, p = 0.100). In addition, Bland and Altman plots evidenced acceptable agreement between them. On average, athletes took ~140 s to achieve maximum oxygen uptake and maintained it for ~180 s. Therefore, the peak velocity intensity can be used as an indicator of maximal aerobic power of futsal athletes and the time limit can be used as a reference for training prescription.

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Abstract The purpose of this study was to determine the level of agreement between critical power (CP) and intensity corresponding to 50% of the difference (50% ∆) between oxygen uptake (VO2) at lactate threshold (LT) and maximal oxygen uptake (VO2max) in untrained subjects during cycling exercise. Fifteen healthy male subjects (age: 26.0 ± 3.5 years; body weight: 76.6 ± 10.4 kg; height: 178.2 ± 7.6 cm) volunteered to participate in the study. Each subject performed a series of tests to determine LT, VO2LT, CP, VO2CP, 50% ∆, VO250% ∆, and VO2max. The values LT, CP, VO2CP, 50% ∆, VO250% ∆ and VO2max were 109 ± 15 W, 1.84 ± 0.23 L.min-1, 207 ± 17 W, 2.78 ± 0.27 L.min-1, 206 ± 19 W, 2.77 ± 0.29 L.min-1, and 3.71 ± 0.49 L.min-1, respectively. No signficant difference was found between CP and 50% ∆ (t = 0.16; p = 0.87) or between VO2CP and VO250% ∆ (t = 0.12; p = 0.90). However, the bias ± 95% limits of agreement for comparison between CP and 50% ∆ and between VO2CP and VO250% ∆ were 1 ± 27 W (0.3 ± 14.1%) and 0.01 ± 0.24 L.min-1 (0.2 ± 8.9%), respectively. In summary, the mean CP and 50% ∆ values were not significantly different. However, considering the limits of agreement between the two intensities, CP estimated based on 50% ∆ might result in a remarkable error when the absolute variability of individual differences is taken into account.

Resumo A proposta deste estudo foi determinar o nível de concordância entre a potência crítica (PC) e a intensidade correspondente a 50% da diferença (50% ∆) entre o consumo de oxigênio (VO2) no limiar de lactato (LL) e o consumo máximo de oxigênio (VO2max) em sujeitos não treinados durante o exercício de ciclismo. Quinze sujeitos saudáveis do sexo masculino (idade: 26,0 ± 3,5 anos; massa corporal: 76,6 ± 10,4 kg; estatura: 178,2 ± 7,6 cm) participaram deste estudo. Cada sujeito realizou uma série de testes para determinar o LL, VO2.LL, PC, VO2.PC, 50% ∆, VO250% ∆ e VO2max. Os valores de LL, VO2LL, PC, VO2PC, 50% ∆, VO250% ∆ e VO2max foram 109 ± 15 W, 1,84 ± 0,23 L.min-1, 207 ± 17 W, 2,78 ± 0,27 L.min-1, 206 ± 19 W, 2,77 ± 0,29 L.min-1 e 3,71 ± 0,49 L.min-1, respectivamente. Nenhuma diferença significavita foi encontrada entre a PC e o 50% ∆ (t = 0.16; p = 0.87) e entre o VO2PC e o VO250% ∆ (t = 0.12; p = 0.90). Entretanto, o bias ± 95% dos limites de concordância para as comparações entre a PC e o 50% ∆ e entre o VO2PC e o VO250% ∆ foram 1 ± 27 W (0,3 ± 14,1%) e 0,01 ± 0,24 L.min-1 (0,2 ± 8,9%), respectivamente. Em resumo, os valores médios de PC e 50% ∆ não foram significativamente diferentes. No entanto, a PC estimada pelo 50% ∆ pode resultas em um erro significativo quando a cariabilidade individual absoluta é considerada.

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NEW FINDINGS: What is the central question of this study? Does the rate of utilization of W' (the curvature constant of the power-duration relationship) affect fatigue during severe-intensity exercise? What is the main finding and its importance? The magnitude of fatigue after two severe-intensity exercises designed to deplete the same fraction of W' (70%) at two different rates of utilization (fast versus slow) was similar after both exercises. Moreover, the magnitude of fatigue was related to critical power (CP), supporting the contention that CP is a key determinant in fatigue development during high-intensity exercise. Thus, the CP model is a suitable approach to investigate fatigue mechanisms during high-intensity exercise. The depletion of W' (the curvature constant of the power-duration relationship) seems to contribute to fatigue during severe-intensity exercise. Therefore, the aim of this study was to determine the effect of a fast versus a slow rate of utilization of W' on the occurrence of fatigue within the severe-intensity domain. Fifteen healthy male subjects performed tests to determine the critical power, W' and peak torque in the control condition (TCON ) and immediately after two fatiguing work rates (THREE and TEN) set to deplete 70% W' in either 3 (TTHREE ) or 10 min (TTEN ). The TTHREE and TTEN were significantly reduced (F = 19.68, P = 0.01) in comparison to TCON . However, the magnitude of reduction in peak torque (TTHREE  = -19.8 ± 10.1% versus TTEN  = -16.8 ± 13.3%) was the same in the two fatiguing exercises (t = -0.76, P = 0.46). There was a significant inverse relationship between the critical power and the reduction in peak torque during both THREE (r = -0.49, P = 0.03) and TEN (r = -0.62, P = 0.02). In contrast, the W' was not significantly correlated with the reduction in peak torque during both THREE (r = -0.14, P = 0.33) and TEN (r = -0.30, P = 0.10). Thus, fatigue following severe-intensity exercises performed at different rates of utilization of W' was similar when the same work was done above the critical power (i.e. same amount of W' used).

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Abstract Futsal has intermittent characteristics with different requirements of displacements and changes of direction, requiring simultaneously aerobic and anaerobic capacities of athletes. So, during counter-attacks and returns to defense or fast movements to get rid or perform marking, there is maximum mobilization of specific capabilities of the sport and the ability to perform high-intensity intermittent exercise is a key factor of performance. The aim of this study was to perform an expositive review on the physiological characteristics, high-intensity interval training and aerobic evaluation methods that have been used and suggested in scientific literature in original studies. A search in scientific portals Google Scholar, Scopus®, SciELO®, ScienceDirect® (Elsevier) and PubMed® was conducted to find articles with publication date since 2000 using the following terms in different combinations: “Futsal”, “performance”, “aerobic evaluation”, “high-intensity interval training”, “field tests” and their variations in English. Analysis of physiological indexes related to game performance can help in the knowledge about the aerobic fitness of Futsal players and improve training assessment, prescription and monitoring, also serving as a reference to assist professionals of this sport in the preparation of high intensity interval training programs to meet the particular needs of the sport. Field tests with specific features of the sport were created as a means of assessment and also training prescription and are recommended due to their specificity and ecological validity.

Resumo O futsal apresenta características intermitentes com diferentes exigências de deslocamentos e mudanças de direção, exigindo simultaneamente as capacidades aeróbias e anaeróbias dos atletas. Assim, durante os contra-ataques e retornos à defesa, ou movimentações rápidas para se desmarcar ou realizar marcação, há uma mobilização máxima das capacidades específicas da modalidade, sendo que a habilidade de realizar exercícios intermitentes de alta intensidade é um fator decisivo da performance. O objetivo do presente trabalho foi realizar uma revisão de literatura expositiva sobre as características fisiológicas, treinamento intervalado de alta intensidade e métodos de avaliação aeróbia que vêm sendo utilizados e sugeridos na literatura científica em estudos originais. Realizou-se uma pesquisa nos portais científicos da Google Scholar, Scopus®, SciELO®, ScienceDirect® (Elsevier) e PubMed® buscando artigos com data de publicação a partir do ano 2000 pelos seguintes termos em diferentes combinações: “futsal”, “performance”, “avaliação aeróbia”, “treinamento intervalado de alta intensidade”, “testes de campo” e suas variações em inglês. A análise dos índices fisiológicos relacionados à performance de jogo podem auxiliar no conhecimento a respeito da aptidão aeróbia de jogadores de futsal e aprimorar a avaliação, prescrição e acompanhamento do treinamento. Adicionalmente, servem de referência para auxiliar os profissionais da modalidade na elaboração de programas de treinamento intervalado de alta intensidade que atendam às necessidades específicas do esporte. Os testes de campo com características próprias da modalidade foram criados como forma de avaliação e também prescrição de treinamento e são recomendados pela especificidade e validade ecológica que possuem.

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Abstract The aim of this study was to evaluate the effect of 9 weeks of the “FIFA 11+” warm-up program on vertical jump performance in soccer players. The study included 20 athletes of the Under-20 category from a Brazilian championship serie A team (age: 18.3±1.6 years; years of training: 8.2±1.3; body weight: 74.0±7.1 kg, height: 177.8±6.5 cm, and fat percentage: 10.7±1.9%), divided into an intervention group (G11+; n=10) and a control group (CG; n=10). The athletes were evaluated before and after the intervention regarding countermovement jump (CMJ) and squat jump (SJ) performed on a force platform. The maximum jump height was considered for data analysis. A mixed-model ANOVA was used to verify the main time vs. group effects. Both groups underwent the same training routine (physical, technical, and tactical) and only differed in terms of the proposed warm-up, which was performed three times per week in G11+. No significant difference in jump performance was observed in CG, while G11+ showed significant improvement in both types of jumps (CMJ: F=26.23, p<0.01; %change=11.3; SJ: F=23.16, p<0.01, %change=9.8). In conclusion, 9 weeks of intervention with the “FIFA 11+” warm-up program during routine training promoted significant improvement in jump performance.

Resumo O objetivo do estudo foi verificar o efeito do treinamento de nove semanas de um programa de aquecimento “FIFA 11+” na performance de saltos verticais (SV) de jogadores de futebol. Participaram do estudo 20 atletas da categoria sub-20 de uma equipe da série A do campeonato brasileiro (idade: 18,3 ± 1,6 anos; tempo de prática 8,2 ± 1,3 anos; massa corporal de 74,0 ± 7,1 kg; estatura 177,8 ± 6,5 cm e percentual de gordura 10,7 ± 1,9 %), separados em grupo intervenção (G11+; n=10) e grupo controle (GC; n=10). Os Atletas foram avaliados antes (Pré) e após (Pós) a intervenção por meio dos saltos Countermoviment Jump (CMJ) e Squat Jump (SJ), realizados em uma plataforma de força, sendo os valores máximos da altura dos saltos adotados para análise. Foi realizada uma ANOVA modelo-misto para verificar os possíveis efeitos tempo x grupo. Nível de significância adotado de p < 0,05. Ambos os grupos foram submetidos à mesma rotina de treinamento (físico, técnico e tático), diferindo apenas o aquecimento proposto, que foi realizado três vezes por semana para o G11+. O GC não apresentou alteração significativa na performance dos saltos, porém o G11+ apresentou melhora significativa para ambos os tipos de saltos (CMJ: F= 26,23, p<0,01; %mudança= 11,3; SJ: F= 23,16, p<0,01, %mudança= 9,8). Desta forma, as nove semanas de intervenção com o programa de aquecimento “FIFA 11+” na rotina de treinamento promoveu um aumento significativo no desempenho dos saltos.