Physiological, anthropometric, strength, and muscle power characteristics correlates with running performance in young runners.

The purpose of this study was to investigate the relationship between physiological, anthropometric, strength, and muscle power variables and a 5-km time trial (5kmT) in young runners. Twenty-three runners volunteered to participate in this study. Height, body mass, body fat, and fat-free mass (FFM) were measured. The subjects underwent laboratory testing to determine maximal oxygen uptake ((Equation is included in full-text article.)), velocity at ventilatory threshold (VVT), running economy (RE), velocity associated with maximal oxygen uptake ((Equation is included in full-text article.)), and peak velocity (PV). Peak torque, total work, and power were measured by an isokinetic dynamometer at 60°·s(-1) and 240°·s(-1) angular velocities. Right and left knee flexor and extensor torques were evaluated. Finally, the participants performed a 5kmT. Multiple regression and correlation analysis were used to determine the variables that significantly related to 5kmT. Strength and muscle power variables did not correlate with 5kmT. However, most physiological variables were associated with 5kmT. Velocity at ventilatory threshold alone explains 40% of the variance in 5kmT. The addition of the RE at speed 11.2 km·h(-1) (RE11.2) and FFM to the prediction equation allowed for 71% of the adjusted variance in 5kmT to be predicted. These results show that strength and muscle power variables are not good predictors of 5kmT; however, the physiological variables presented high prediction capacity in the 5kmT. Moreover, the anthropometric measures showed significant influence in performance prediction.

Comparação das respostas fisiológicas e perceptuais obtidas durante caminhada na esteira em ritmo autosselecionado entre os sexos / Physiological and perception responses comparison during treadmill walking at self-selected pace between genders

O objetivo do presente estudo foi comparar as respostas fisiológicas e perceptuais entre os sexos durante a caminhada na esteira em ritmo autosselecionado. Participaram 17 homens e 17 mulheres, fisicamente ativos, com média de idade de 23,32 ± 3,06 anos, submetidos a duas sessões experimentais: (I) avaliação antropométrica e teste incremental máximo, e (II) um teste de 20 minutos de caminhada na esteira em ritmo autosselecionado. Para a análise estatística, empregou-se teste t de Student para medidas independentes no intuito de verificar as possíveis diferenças entre os sexos, adotando p < 0,05. A velocidade de caminhada autosselecionada pela amostra masculina foi superior à verificada na feminina (1,65 ± 0,18 e 1,50 ± 0,12m·seg-1, respectivamente) o que consequentemente resultou em maior O2 absoluto nos homens comparado às mulheres (21,2 ± 5,5 e 18,3 ± 2,7, respectivamente). No entanto, ambos os sexos buscaram caminhar em mesma intensidade relativa % O2máx, (37,5 ± 10,7 homens e 40,3 ± 7,2 mulheres). Em relação à percepção subjetiva de esforço (PSE), podemos verificar que ambos os sexos não demonstraram diferenças significativas (10,2 ± 1,0 homens e 9,8 ± 1,2 mulheres). Os achados do presente estudo demonstram que, independente do sexo, jovens adultos fisicamente ativos autosselecionaram similar intensidade relativa que refletiu em similar PSE. Além disso, a caminhada em intensidade autosselecionada demonstra-se como estímulo insuficiente para proporcionar melhora no condicionamento cardiorrespiratório nesta população.

The aim of this study was to compare physiological and perception responses between genders during treadmill walking at self-selected pace. 17 men and 17 women aged 23.32 ± 3.06 yr were investigated: (I) anthropometric assessment and incremental exhaustion test, (II) a 20-minute walking bout on treadmill at their self-selected pace. The independent t test was utilized to verify any gender differences, with a level of p < 0.05. The self-selected walking pace was significantly greater in men than women (1.65 ± 0.18 and 1.50 ± 0.12 m·sec-1, respectively), and consequently resulted in higher absolute VO2 for men compared to women (21.2 ± 5.5 and 18.3 ± 2.7, respectively). However, both genders self-selected a similar relative exercise intensity %VO2max (37.5 ± 10.7 and 40.3 ± 7.2 for men and women, respectively). The subjective perceived exertion (SPE) did not differ between genders (10.2 ± 1.0 and 9.8 ± 1.2 for men and women, respectively). The results of the present study demonstrated that regardless of gender, physically active young adults self-selected a similar relative exercise intensity that reflected in similar SPE. Furthermore, gait at self-selected intensity was insufficient to improve cardiorespiratory fitness in this sample.

Respostas fisiológicas durante a caminhada na esteira em ritmo autosselecionado: comparação entre os gêneros / Physiological responses during treadmill walking at a self-selected pace: comparison between genders

O objetivo do presente estudo foi comparar o O2Máx, FCMáx, %FCR, % O2R e METs entre os gêneros durante a caminhada em ritmo autosselecionado e verificar se a intensidade selecionada apresenta-se fisiologicamente efetiva para manutenção ou melhora da aptidão cardiorrespiratória (ACR). Participaram 17 homens e 17 mulheres com média de idade de 23,32 ± 3,06 anos, submetidos: (I) avaliação antropométrica e teste incremental máximo em esteira, (II) um teste de 20-minutos de caminhada em ritmo autosselecionado. Na análise estatística, empregou-se um teste t Student para medidas independentes, adotandop<0,05. Nenhuma diferença significativa entre os gêneros para o %FCMáx (58,38 ± 8,86 para homens e 62,12 ± 5,91 para mulheres), %VO2Máx (37,54 ± 10,75 para homens e 40,34 ± 7,27 para mulheres), %FCR (36,83 ± 11,77 para homens e 38,46 ± 8,33 para mulheres) e % O2R (31,88 ± 11,17 para homens e 34,70 ± 7,74 para mulheres). Entretanto, verifica-se quea velocidade de caminhada (km.h-1) selecionada foi superior no grupo masculino (5,96 ± 0,66; p<0,001) comparado ao feminino (5,41 ± 0,46), o que, possivelmente, propiciou que os METs fossem maiores nos homens (6,07 ± 1,57, p<0,05) comparado as mulheres (5,23 ± 0,77). Conclui-se que ambos os gêneros autosselecionam um ritmo de caminhada considerado não efetivo para manutenção e melhora da ACR, contudo, os valores de METs demonstram-se dentro do indicado para manutenção e redução do peso corporal. As diferenças encontradas entre os gêneros para o METs podem ser decorrentes das diferenças apresentadas para a velocidade de caminhada e características antropométricas.

The objective of this study was to compare % O2Max, %HRMax, %HRR, % O2R, and MET between genders during walking at a self-selected pace and to determine whether the self-selected pace was physiologically effective in maintaining and improving cardiorespiratory fitness. Seventeen men (age: 24.05 ± 3.3 years) and 17 women (age> 22.58 ± 2.67 years)were submitted to two experimental sessions: (I) anthropometric assessment and incremental exhaustion test, and (II) 20-min treadmill walking bouts at a self-selected pace. The independent Student t-test was used to determine differences between genders, at an alpha level of 0.05. No significant differences in %HRMax (58.38 ± 8.86 for men and 62.12 ± 5.91 for women), % O2Max (37.54 ± 10.75 for men and 40.34 ± 7.27 for women), %HRR (36.83 ± 11.77 for men and 38.46 ± 8.33 for women), or % O2R (31.88 ± 11.17 for men and 34.70 ± 7.74 for women) wereobserved between genders. However, the walking speed selected (km.h-1) was higher in men (5.96 ± 0.66, p<0.001) than women, a finding that probably resulted in higher MET values for men (6.07 ± 1.57, p<0.05) compared to women (5.23 ± 0.77). In conclusion, both genders selected a walking pace that was not effective in maintaining or improving cardiorespiratory fitness, but MET values were within the range indicated for the maintenance and reduction of body weight. The differences in METs observed between genders might be due to differences in walking speedand anthropometric characteristics.