Cecília Segabinazi Peserico

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.

Reliability of peak running speeds obtained from different incremental treadmill protocols.

Abstract This study compared the values and reliability of peak running speeds from incremental treadmill protocols with different speed increments. Thirty-one men, recreational, endurance-trained runners performed, in an alternate order, three continuous tests with different speed increments (0.5, 1 and 2 km · h−1). The tests were repeated using the same order. Peak speed was identified as (1) the greatest speed that could be maintained for a complete minute (Vpeak-60s), (2) the speed of the last complete stage (Vpeak-C) and (3) the speed of the last complete stage added to the product of the speed increment and the completed fraction of the incomplete stage (Vpeak-P). The Vpeak-P was the most reliable, independent of the incremental test protocol (1.5% ≤ CV ≤ 1.8%), and differently from Vpeak-C (1.8% ≤ CV ≤ 2.6%) and Vpeak-60s (1.6% ≤ CV ≤ 3.8%), the Vpeak-P was only slightly influenced by the incremental test protocol. The results suggest that Vpeak-P should be used to assess aerobic capability and monitor training effects and that other determinations of peak speed should be avoided.

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.

Evaluation of the Best-designed Graded Exercise Test to Assess Peak Treadmill Speed.

This study examined the influence of different speed increments during treadmill exercise tests on peak treadmill speed (Vpeak) and its relationship with a 1-h treadmill running performance. 18 male recreational and amateur runners (10-km running pace: 10-15 km·h(-1)) performed, in an alternate order, 3 continuous incremental exercise tests with different speed increments (0.5, 1.0 and 2.0 km·h(-1)) on a motorized treadmill to determine Vpeak. Thereafter they undertook a 1-h time trial on a treadmill. Vpeak was determined 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 product of the speed increment and the completed fraction of the incomplete stage (Vpeak-P). The Vpeak values were highly influenced by the different speed-incremented rates and the Vpeak-P determined during the protocol comprising speed increments of 1 km·h(-1) presented the highest correlation with 1-h time trial performance (r=0.89). The results suggest that a protocol with speed increments comprising 1 km·h(-1) and with a 3-min stage duration should be used as standard for the determination of Vpeak to assess aerobic fitness and predict endurance performance in recreational runners. Furthermore, the Vpeak-P should be used for the determination of Vpeak.

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.

Comparação entre dois métodos objetivos e individuais de determinação da velocidade de corrida no limiar de lactato

The aim of this study was to compare the running speed at lactate threshold (sLT) determined by the objective and individual methods Dmax (sLTDmax) and log-log (sLTlog-log) being expected a better relationship between them than the relationship of them to the fixed lactate concentration method at 3.5 mM (sLT3.5mM). Seventeen amateur women runners, with experience of 10 km road races (age: 42.1 ± 6.7 year; height: 1.63 ± 0.03 m; body mass 57.2 ± 4.9 kg), participated in this study. They performed an incremental exercise test on a motorized treadmill, which the initial speed was 7 km/h, with increments of 1km/h every 3-min. Blood samples were collected between the stages, during a rest of 30-s. The sLT were 10.3 ± 1.4 (sLTlog-log), 10.9 ± 0.8 (sLTDmax) and 11.6 ± 1.2 km/h (sLT3.5mM) being the sLT3.5mM significantly higher than sLTlog-log (P <0.001) and sLTDmax (P = 0.024). Despite that, the limits of agreement range (±1.96 SD) among the sLT was similar, varying between ±1.48 and ±1.77 km/h and the correlation between sLT3.5mM and the speeds sLTlog-log (r = 0.70) and sLTDmax (r = 0.78) was higher than the correlation between sLTlog-log and sLTDmax (r = 0.65). In summary, the sLTlog-log and sLTDmax speeds did not show a better relationship between themselves than the relationship of them to the sLT3.5mM.

Comparison between exponential and polynomial curve fitting on the determination of the lactate threshold by the Dmax method

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.

Comparación entre el ajuste de la curva exponencial y polinómica en la determinación del umbral de lactato por el 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.