18 may 2012
Several researchers have demonstrated that, in the endurance performance, the ability to run without accumulating lactate is more important than the maximum oxygen uptake(VO2max)or the energy cost of running (Cr) (Yoshida et al, 1993; Grant et al, 1997).
Autor(es):Santos-Concejero1,2, J; Granados1, C; Bidaurrazaga-Letona1, I; Zabala-Lili1, J; Gil1, SM
:1Departamento Educación Física y Deportiva, Facultad de Ciencias de la Actividad Física y del Deporte, Universidad del País Vasco, UPV/EHU. 2Departamento de Fisiología, Facultad de Medicina y Odontología, Universidad del País Vasco, UPV/EHU.
Congreso: IV Congreso Internacional de Ciencias del Deporte y la Educación Física. (VIII Seminario Nacional de Nutrición, Medicina y Rendimiento Deportivo)
Pontevedra, España, 10-12 Mayo 2012
Palabras Clave: :
Onset of blood lactate accumulation as a predictor of performance in top athletes
INTRODUCTIONSeveral researchers have demonstrated that, in the endurance performance, the ability to run without accumulating lactate is more important than the maximum oxygen uptake(VO2max)or the energy cost of running (Cr) (Yoshida et al, 1993; Grant et al, 1997). This concept of anaerobic threshold was firstly proposed in order to express the loss of linear relationship between ventilation and the oxygen uptake (VO2), which coincides with lactate accumulation (Wasserman & McIlroy, 1964). Later, it was redefined as the work rate or VO2 just below the point where lactate begins to systematically increase from its resting level exercise value during an incremental exercise test (Wasserman et al, 1981). Since then, different blood lactate indices have been proposed to measure the ability to run without accumulating lactate, such as lactate threshold (LT), maximal lactate steady state (MLSS), or the onset of blood lactate accumulation (OBLA). OBLA is the exercise intensity corresponding to 4 mmol·L-1 lactate concentration, which represents the maximal workload of steady-state lactate concentration (Figueira et al, 2008) and which corresponds to the transition from a tolerable workload to a more severe intensity (Chmura & Nazar, 2010). Different studies have shown the importance of OBLA in the long distance running performance and it has also been suggested as a sensitive indicator of the training induced adaptations and a sensitive discriminator between elite and good athletes (Tanaka, 1990). It should be noted that many of these studies where performed with only a small number of participants (Abe et al, 1999), non-trained subjects (Tanaka et al, 1983) or in non-elite athletes (Sjodin& Jacobs, 1981; Grant et al, 1997). Therefore, the main purpose of this study was to investigate if the onset of blood lactate accumulation velocity (VOBLA) could be a good predictor of running performance in well-trained endurance athletes.
METHODSSubjects Twenty-two well-trained runners (28.6 ± 6.4 years) participated in the study. Before participation, subjects were medically examined to ensure that they had no signs of cardiovascular, musculoskeletal and metabolic diseases. The Ethics Committee for research on Human subjects at the University of Basque Country (CEISH/GIEB) approved this study. All athletes were informed about all the tests and the possible risks involved and signed a written informed consent prior to testing. All subjects had participated in international or national level competitions. The best record in 3000 meters and 10000 meters of each subject was recorded and the pace was calculated (V3K and V10K, respectively). Athletes were encouraged to be well rested and to abstain from hard training sessions and competitions the days before testing. Procedures Anthropometry.Height (cm) and body mass (kg) were measured with the use of a precision stadiometer and a balance (Seca, Bonn, Germany), and body mass index (BMI) was calculated. Eight skinfold sites (biceps, triceps, subscapular, supraspinale, abdominal, suprailiac, mid-thigh, and medial calf) were measured in duplicate with a skinfold caliper (Holtain, Crymych, UK) by the same researcher and the sum of skinfolds was determined. The body fat percentage was calculated for each athlete, as described elsewhere (Yuhasz, 1974). Peak treadmill lactate test. All subjects completed a maximal incremental running test at 1% slope on a treadmill, which started at 9 km·h-1 without previous warm up. The velocity was increased by 1.5 km·h-1 every 4 minutes to exhaustion, with 1 minute of recovery between each stage. During the test, heart rate (HR) (Polar RS800, Kempele, Finland) and gas exchange were continuously measured (Ergocard, Medisoft, Sorinnes, Belgium). Immediately after each exercise stage, a 25 ?l sample of capillary blood was drawn from the earlobe and immediately analyzed in order to determine the blood lactate concentration (Lactate Pro, Arkray, KDK Corporation, Kyoto, Japan), which has been previously validated as an effective analyzer for lactate measurements (Tanner et al, 2010). Determination of VOBLA. VOBLA was calculated by interpolation, expressing the collected blood lactate data of each subject in the peak treadmill lactate test as a function of running velocity. A quadratic equation was used to perform the regression of the lactate concentration and velocity Statistics Statistical analyses of data were performed using the Statistical Package for the Social Sciences 15.0 software package (StatSoft, USA). Results are all presented as means, standard deviation (SD) and coefficient of variance (CV; SD·mean-1·100). The relationships between VOBLA and the average velocities of the individual´s running performance were evaluated using a linear regression analysis. Significance for all analyses was set at P<0.05.
RESULTSTable 1 shows the results of the anthropometrical parameters and running performance data. The CV was lower than 10% in the height, mass and BMI, despite the big variations in factors related to body fat. A small CV of the athlete´s performance was observed according to their V3K and V10K results (<7%), which indicates that all athletes were of similar athletic level.
Table 1. Anthropometrical parameters and performance indicator of the subjects (n=22)Table 1. Onset of blood lactate accumulation as a predictor of performance in top athletes n, number of subjects; BMI, Body Mass Index, ? 8 skinfold, (biceps, triceps, subscapular, supraespinal, abdominal, suprailiac, midthigh, and medial calf); ? 6 skinfold, (triceps, subscapular, abdominal, suprailiac, midthigh, and medial calf).%BF, percentage of body fat; VOBLA, onset of blood lactate accumulation velocity; V3K, 3 km race pace; V10K, 10 km race pace. Values are means ± SD. Maximal test results are listed in table 2. All physiological values, apart from the maximal lactate concentration ([La-]max), did not exceed the 10% in the CV, which means that the subjects were a homogeneous group.
Table 2. Maximal test results (n=22)Table 2. Onset of blood lactate accumulation as a predictor of performance in top athletes n, number of subjects; VEmax, maximum minute ventilation rate; VO2peak, peak oxygen uptake rate; HRmax, maximum heart rate; [La-]max, maximum lactate concentration; RERmax, maximum respiratory exchange ratio. Values are means ± SD. Figure 1 shows the relationship of VOBLA and running performance (V3K and V10K). VOBLA was closely correlated with V3K and V10K (r=0.561, P<0.05 and r=0.762, P<0.01, respectively) despite the small variation among subject´s running performance. Figure 1. Onset of blood lactate accumulation as a predictor of performance in top athletes Figure 1.The relationship between running velocity corresponding to the onset of blood lactate accumulation (VOBLA) and the running performance according to the 3 km race velocity (V3K) and 10 km race velocity (V10K).
DISCUSSIONThe major finding in this study was the observed significant relationship between VOBLA and the middle and long distance running performance according to the 3000 and 10000 meters race velocity. These results are in agreement with previous studies, which have shown the validity of VOBLA as a predictor of aerobic performance (Billat, 1996), especially in marathon (Sjodin & Jacobs, 1981) and in those running events of 16 km or shorter distances (Tanaka, 1990). Nevertheless, other studies did not report any relationships between VOBLA and 10 Km performance (Abe et al, 1999), maybe due to the fact that the study was not performed under laboratory conditions and with a small number of subjects. Several studies have demonstrated that VOBLA is significantly related to middle distance running performance in elite female athletes (Yoshida et al, 1993) and non-elite male athletes (Grant et al, 1997). Nevertheless, the current study is the first finding a significant relationship between VOBLA and middle distance performance according to the 3000 meters race pace in well-trained male athletes In summary, a high relationship between VOBLA and V3K and V10K was observed in current study, which may indicate that this parameter is an appropriate index to predict the running performance.
- The VOBLA seems to be a good predictor of running performance in both 3000 and 10000 meter races in endurance athletes.
REFERENCESAbe D, Sakaguchi Y, Tsuchimochi H, Endo M, Miyake K, Miyahiro S, Kanamaru K, Niihata S. Assessment of long-distance running performance in elite male runners using onset of blood lactate accumulation.Appl Human Sci. 1999;18(2):25-9. Billat LV. Use of blood lactate measurements for prediction of exercise performance and for control of training. Recommendations for long-distance running. Sports Med. 1996;22(3):157-75. Chmura J, Nazar K. Parallel changes in the onset of blood lactate accumulation (OBLA) and threshold of psychomotor performance deterioration during incremental exercise after training in athletes.Int J Psychophysiol. 2010;75(3):287-90. Figueira TR, Caputo F, Pelarigo JG, Denadai BS. Influence of exercise mode and maximal lactate-steady-state concentration on the validity of OBLA to predict maximal lactate-steady-state in active individuals.J Sci Med Sport. 2008;11(3):280-6. Grant S, Craig I, Wilson J, Aitchison T. The relationship between 3 km running performance and selected physiological variables. J Sports Sci. 1997;15(4):403-10. Sjödin B, Jacobs I. Onset of blood lactate accumulation and marathon running performance. Int J Sports Med. 1981;2(1):23. Tanaka K. Lactate-related factors as a critical determinant of endurance. Ann Physiol Anthropol. 1990;9(2):191-202. Tanaka K, Matsuura Y, Kumagai S, Matsuzaka A, Hirakoba K, Asano K. Relationships of anaerobic threshold and onset of blood lactate accumulation with endurance performance. Eur J Appl Physiol Occup Physiol. 1983;52(1):51-6. Tanner RK, Fuller KL, Ross M.L. Evaluation of three portable blood lactate analysers: Lactate Pro, Lactate Scout and Lactate Plus. Eur J Appl Physiol. 2010;109(3):551-9. Wasserman K, McIlroy MB. Detecting the threshold of anaerobic metabolism in cardiac patients during exercise.http://www.ncbi.nlm.nih.gov/pubmed/14232808 Am J Cardiol. 1964;14:844-52. Wasserman K, Whipp BJ, Davis JA. Respiratory physiology of exercise: metabolism, gas exchange, and ventilatory control. Int Rev Physiol. 1981;23:149-211. Yoshida T, Udo M, Iwai K, Yamaguchi T. Physiological characteristics related to endurance running performance in female distance runners. J Sports Sci. 1993;11(1):57-62.
Yuhasz MS. Physical fitness Manual, London, Ontario: University of Western Ontario; 1974. 144 p.