Paulo Victor Mezzaroba

Incremental test design, peak ‘aerobic’ running speed and endurance performance in runners

OBJECTIVES Peak running speed obtained during an incremental treadmill test (Vpeak) is a good predictor of endurance run performance. However, the best-designed protocol for Vpeak determination and the best Vpeak definition remain unknown. Therefore, this study examined the influence of stage duration and Vpeak definition on the relationship between Vpeak and endurance run performance. DESIGN Relationship. METHODS Twenty-seven male, recreational, endurance-trained runners (10-km running pace: 10-17 k mh(-1)) performed, in counterbalanced order, three continuous incremental treadmill tests of different stage durations (1-, 2-, or 3-min) to determine Vpeak, and two 5-km and two 10-km time trials on a 400-m track to obtain their 5-km and 10-km run performances. Vpeak was defined as either (a) the highest speed that could be maintained for a complete minute (Vpeak-60 s), (b) the speed of the last complete stage (Vpeak-C), or (c) the speed of the last complete stage added to the multiplication of the speed increment by the completed fraction of the incomplete stage (Vpeak-P). RESULTS The Vpeak determined during the 3-min stage duration protocol was the most highly correlated with both the 5-km (r=0.95) and 10-km (r=0.92) running performances and these relationships were minimally influenced by the Vpeak definition. However, independent of the stage duration, the Vpeak-P provided the highest correlation with both running performances. CONCLUSIONS Incremental treadmill tests comprising 3-min stage duration is preferred to 1-min and 2-min stage duration protocols in order to determine Vpeak to accurately predict 5-km and 10-km running performances. Further, Vpeak-P should be used as standard for the determination of Vpeak.

The Dmax is highly related to performance in middle-aged females.

The present study examined whether the running speed at the lactate threshold estimated by the maximal deviation method (LT (Dmax)) is highly correlated and in agreement with 10-km road race performance (S (10 km)) in middle-aged female runners. Additionally, the LT (Dmax) was compared with the visual detection of the inflection point (LT (Visual)), the fixed lactate level of 4 mmol.L (-1) (LT (4)) and the peak speed (S (peak)) in relation to performance. Sixteen middle-aged, recreational female runners performed a discontinuous, incremental treadmill test. The initial speed was set at 7 km.h (-1), and this speed was increased every 3 min by 1 km.h (-1) with a 30-s rest between the stages used for earlobe capillary blood sample collection. All of the participants took part in the same local 10-km road race, and S (10 km) mean speed was calculated. The speeds (mean ± SD) were 10.5 ± 1.0 (S (10 km)), 10.5 ± 1.0 (LT (Visual)), 10.9 ± 0.9 (LT (Dmax)), 11.4 ± 1.3 (LT (4)) and 13.5 ± 1.1 km.h (-1) (S (peak)). The LT (Dmax) had the narrowest limits of agreement (0.3 ± 0.4 km.h (-1)) and was the most highly correlated with the S (10 km) ( R=0.98), followed by the S (peak) ( R=0.95), LT (4) ( R=0.85) and LT (Visual) ( R=0.81). In conclusion, the LT (Dmax) should be more widely used to estimate long-distance performance and to verify improvements in training.

Effect of stage duration on maximal heart rate and post-exercise blood lactate concentration during incremental treadmill tests.

OBJECTIVES This study compared the responses during maximal incremental treadmill tests of 1-min, 2-min, and 3-min stage durations mainly in terms of maximal heart rate (HRmax) and peak blood lactate concentration (LApeak). DESIGN Repeated-measures. METHODS Thirty-four male, recreational, endurance-trained runners (40±13 years) performed three tests on a motorized treadmill. The tests started at 8kmh(-1) with increments of 1kmh(-1) every 1min for the short-stage protocol, every 2min for the intermediate-stage protocol, and every 3min for the long-stage protocol. LApeak was defined for each subject as the highest value among the lactate concentrations determined at the end of each test and at the third, fifth and seventh minutes after test, during passive recovery. RESULTS Analysis of variance revealed a significant effect of the stage duration on the HRmax (p=0.003) and LApeak (p=0.001). The HRmax was higher in the intermediate-stage compared to the short-stage protocol (184.8±12.7 vs. 181.8±12.1beatsmin(-1), p<0.001), but no significant differences were found between the long-stage (183.1±12.1beatsmin(-1)) and the intermediate-stage or short-stage protocols (p>0.05). The LApeak was lower in the long-stage compared to the short-stage and intermediate-stage protocols (7.9±2.2 vs. 9.4±2.2 and 9.2±1.9mmolL(-1), respectively, p<0.05). Further, blood lactate reached peak concentration at the fifth minute after test for all the protocols. CONCLUSIONS Thus, HRmax and LApeak depend on the stage duration of the incremental test, but the moment at which blood lactate reaches peak concentration is independent of the duration. Further, we suggest 2-min stage duration protocols to determine HRmax.

Gender and distance influence performance predictors in young swimmers

Predictors of performance in adult swimmers are constantly changing during youth especially because the training routine begins even before puberty in the modality. Therefore this study aimed to determine the group of parameters that best predict short and middle swimming distance performances of young swimmers of both genders. Thirty-three 10-to 16-years-old male and female competitive swimmers participated in the study. Multiple linear regression (MLR) was used considering mean speed of maximum 100, 200 and 400 m efforts as dependent variables, and five parameters groups as possible predictors (anthropometry, body composition, physiological and biomechanical parameters, chronological age/pubic hair). The main results revealed explanatory powers of almost 100% for both genders and all performances, but with different predictors entered in MLR models of each parameter group or all variables. Thus, there are considerable differences in short and middle swimming distance, and males and females predictors that should be considered in training programs.

Indicadores antropométricos e fisiológicos de uma amostra de atletas brasileiros de rugby

Verificou-se parâmetros fisiologicos e antropometricos de jogadores de rugby. Quinze atletas, agrupados de acordo com a posicao de jogo: forwards (GF) e backs (GB) realizaram avaliacao antropometrica e teste de potencia anaerobia com analise do lactato sanguineo, frequencia cardiaca e percepcao subjetiva de esforco. O teste t de Student mostrou diferencas entre grupos para as variaveis antropometricas, em especial massa corporal (GF=102,6±16,0 kg; GB=80,0±6,8 kg) e massa gorda (GF=28,0±10,6 kg; GB=13,8±5,6 kg), mas nao para as variaveis mensuradas no teste de potencia. Alem disso, o teste de correlacao de Pearson mostrou influencia negativa da massa gorda no tempo de teste para GF (r=0,73) e positiva da massa isenta de gordura na potencia para GB (r=0,80), ressaltando que a composicao corporal influencia a performance no rugby, e deve ser utilizada juntamente a parâmetros fisiologicos para discriminar posicoes nesta modalidade.

Comparação entre os ajustes de curva exponencial e polinomial na determinação do limiar de lactato pelo método Dmax

Comparou-se a velocidade de corrida no limiar de lactato (vLL) determinada pelo metodo Dmax utilizando-se os ajustes de curva exponencial mais constante (vLLexp) e polinomial de terceira ordem (vLLpol). Dezessete corredoras recreacionais realizaram um teste incremental descontinuo em esteira rolante ate a exaustao voluntaria com coleta de sangue entre os estagios para analise do lactato. A vLLExp (10,9 ± 0,8 km/h) foi estatisticamente diferente (P < 0,05) da vLLPol (10,4 ± 1,1 km/h) utilizando-se o teste t de Student pareado. A correlacao entre a vLLExp e a vLLPol foi de r = 0,84. As correlacoes entre a velocidade pico e as vLL foram r = 0,94 (vLLexp) e r = 0,69 (vLLpol). Foi concluido que a escolha da curva de regressao do lactato sanguineo influi no valor da vLL, sendo a vLLpol consistentemente inferior a vLLexp.

Comparação entre os métodos direto e indireto de determinação do consumo máximo de oxigênio em mulheres corredoras

O objetivo deste estudo foi comparar os valores de 2max determinados diretamente por um sistema de ergoespirometria com os valores preditos indiretamente pelo sistema ErgoPC durante um teste de esforco maximo realizado por mulheres corredoras. Participaram 20 mulheres corredoras treinadas (42,7 ± 6,4 anos; 1,64 ± 0,04m; 58,3 ± 5,8kg; IMC 21,7 ± 1,9kg/m2 e 22,3 ± 3,5%G). Os sujeitos foram submetidos a avaliacao da composicao corporal e a um teste de esforco progressivo em esteira ergometrica (Inbrasport, Porto Alegre, RS, Brasil) para mensuracao da aptidao aerobia (2max). A velocidade inicial foi de 7km/h com incrementos de 1km/h a cada tres minutos, sendo mantida uma inclinacao constante durante todo o teste equivalente a 1%. As participantes foram fortemente estimuladas a permanecerem no teste o maior tempo possivel, ate a exaustao voluntaria. Para a mensuracao direta do 2max, foi utilizado um sistema de ergoespirometria de circuito aberto (analisador de gases Espirometro 2000 Inbrasport, Porto Alegre, Brasil). A predicao indireta do 2max foi realizada atraves do programa ErgoPC que utiliza a formula de Foster (1996) para tal predicao. Para a analise estatistica, foi realizado o teste t de Student (p < 0,05), para a comparacao dos valores de 2max obtidos de forma direta e indireta, e o teste de correlacao de Pearson, para correlacionar essas duas variaveis. A medida direta do 2max apresentou valor de 51,8 ± 6,8ml/kg/min, e o indireto, 42,8 ± 3,7ml/kg/min. Na comparacao entre os dois resultados foi encontrada diferenca estatisticamente significante entre as variaveis. A correlacao encontrada entre os valores de 2max foi de r = 0,67. Portanto, os resultados mostram que o 2max obtido de forma indireta subestima o valor da medida direta.

Comparison Between Lactate Minimum and Critical Speed Throughout Childhood and Adolescence in Swimmers

This study aimed to examine the influence of age and degree of maturity on the comparison and relationship between lactate minimum intensity (LM) and critical speed (CS) throughout childhood and adolescence in swimmers. Forty-six male swimmers aged between 10 and 18 years were divided into three age groups according to pubertal stages and training status. Maximal efforts of 100 and 400 m and the LM protocol with 200 m performances were executed. CS was determined with a 3-distances combination (100, 200, and 400 m). One-way and mixed analysis of variance for repeated measures, Bland-Altman, Pearson correlation, percentage difference, and effect size were used to compare and examine the relationship between variables in each age group. The results revealed that LM and CS had differences in comparison with one another throughout childhood and adolescence in swimmers, because CS clearly underestimated LM in the 10 to 12.6-year age group, while overestimating it in the 15.4 to 18-year age group of swimmers. Thus, coaches and swimmers must be aware of the age-dependency of CS for indices of aerobic endurance measurements in the initial ages of systematized swimming training.

Effect of age, anthropometry, and distance in stroke parameters of young swimmers.

This study aimed to determine the influence of age, anthropometry, and distance on stroke parameters of 10- to 17-y-old swimmers. Forty-six male swimmers were divided into 4 chronological age groups. Anthropometry and sexual maturity were assessed, and maximal efforts of 100, 200, and 400 m using front-crawl style were performed to determine stroke rate (SR), length (SL), and index (SI). Multiple linear regression, 1-way, and mixed ANOVA for repeated measures were used for statistical analyses. There was significant effect of distance for all stroke parameters (P < .001) and an age effect only for SL and SI (P < .001). Post hoc showed that the 10- to 17-year-old group significantly reduced SR with increasing distance (effect size -0.8 to -1.5 comparing 100, 200, and 400 m) but were not effective in offsetting this adaptation with increased SL, especially from 200- to 400-m distance, at which no group made both adjustments, highlighting the decreased efficiency with significant SI reduction (effect size -0.2 to -0.4 comparing 100, 200, and 400 m). Considering all stroke parameters, the performances were almost 100% explained, but SI itself could explain around 90% of the performance; furthermore, limb length contributed to explain all stroke parameter, and SI was the variable best predicted (around 75%) by anthropometrical (upper limbs and height) and descriptive variables (age and y of systematic training).Thus, distinct effects of distance and advancing age were found during childhood and adolescence on stroke parameters, and SI was highlighted as the best predictor of 100-, 200-, and 400-m maximal performances.

Los indicadores antropométricos y fisiológicos de una muestra brasileña de atletas de rugby

Verificou-se parâmetros fisiologicos e antropometricos de jogadores de rugby. Quinze atletas, agrupados de acordo com a posicao de jogo: forwards (GF) e backs (GB) realizaram avaliacao antropometrica e teste de potencia anaerobia com analise do lactato sanguineo, frequencia cardiaca e percepcao subjetiva de esforco. O teste t de Student mostrou diferencas entre grupos para as variaveis antropometricas, em especial massa corporal (GF=102,6±16,0 kg; GB=80,0±6,8 kg) e massa gorda (GF=28,0±10,6 kg; GB=13,8±5,6 kg), mas nao para as variaveis mensuradas no teste de potencia. Alem disso, o teste de correlacao de Pearson mostrou influencia negativa da massa gorda no tempo de teste para GF (r=0,73) e positiva da massa isenta de gordura na potencia para GB (r=0,80), ressaltando que a composicao corporal influencia a performance no rugby, e deve ser utilizada juntamente a parâmetros fisiologicos para discriminar posicoes nesta modalidade.