ABSTRACT
In 1993, Uwe Tegtbur proposed a useful physiological protocol named the lactate minimum test (LMT). This test consists of three distinct phases. Firstly, subjects must perform high intensity efforts to induce hyperlactatemia (phase 1). Subsequently, 8 min of recovery are allowed for transposition of lactate from myocytes (for instance) to the bloodstream (phase 2). Right after the recovery, subjects are submitted to an incremental test until exhaustion (phase 3). The blood lactate concentration is expected to fall during the first stages of the incremental test and as the intensity increases in subsequent stages, to rise again forming a "U" shaped blood lactate kinetic. The minimum point of this curve, named the lactate minimum intensity (LMI), provides an estimation of the intensity that represents the balance between the appearance and clearance of arterial blood lactate, known as the maximal lactate steady state intensity (iMLSS). Furthermore, in addition to the iMLSS estimation, studies have also determined anaerobic parameters (e.g., peak, mean, and minimum force/power) during phase 1 and also the maximum oxygen consumption in phase 3; therefore, the LMT is considered a robust physiological protocol. Although, encouraging reports have been published in both human and animal models, there are still some controversies regarding three main factors: (1) the influence of methodological aspects on the LMT parameters; (2) LMT effectiveness for monitoring training effects; and (3) the LMI as a valid iMLSS estimator. Therefore, the aim of this review is to provide a balanced discussion between scientific evidence of the aforementioned issues, and insights for future investigations are suggested. In summary, further analyses is necessary to determine whether these factors are worthy, since the LMT is relevant in several contexts of health sciences.
ABSTRACT
Aim: To monitor the training intensity distribution (TID) and the development of physiological and performance parameters. Methods: During their preparation period for the RAAM, 4 athletes (plus 1 additional backup racer) performed 3 testing sessions; one before, one after 3, and one after 6 months of training. VO2max, maximal rate of lactate accumulation (dLa/dtmax), critical power, power output at lactate minimum (MLSSP), peak and mean power output during a sprint test, heart rate recovery, isometric strength, jumping height, and body composition were determined. All training sessions were recorded with a power meter. The endurance TID was analyzed based on the time in zone approach, according to a classical 3-zone model, including all power data of training sessions, and a power specific 3-zone model, where time with power output below 50% of MLSSP was not considered. Results: The TID using the classical 3-zone model reflected a pyramidal TID (zone 1: 63 ± 16, zone 2: 28 ± 13 and zone 3: 9 ± 4%). The power specific 3-zone model resulted in a threshold-based TID (zone 1: 48 ± 13, zone 2: 39 ± 10, zone 3: 13 ± 4%). VO2max increased by 7.1 ± 5.3% (P = 0.06). dLa/dtmax decreased by 16.3 ± 8.1% (P = 0.03). Power output at lactate minimum and critical power increased by 10.3 ± 4.1 and 16.8 ± 6.2% (P = 0.01), respectively. No changes were found for strength parameters and jumps. Conclusion: The present study underlines that a threshold oriented TID results in only moderate increases in physiological parameters. The amount of training below 50% of MLSSp (~28% of total training time) is remarkably high. Researchers, trainers, and athletes should pay attention to the different ways of interpreting training power data, to gain realistic insights into the TID and the corresponding improvements in performance and physiological parameters.
ABSTRACT
Despite the utilization of lactate minimum test (LMT) in training, its intensity response to training remains controversial. The aim of the present study was to verify alterations of LMT intensity in swimmers during a 12-week training protocol. Eight swimmers were submitted to three LMT assessments: beginning of the season, T0; after four, T4; and twelve weeks, T12. The LMT consisted of a 200m maximal effort and, after eight minutes of passive rest, five incremental stages of 200m swimming. The intensities of the incremental stages were defined subjectively ("very light," "light," "moderate," "hard," and "all-out"). The training was divided in two blocks of periodization: endurance training period (ETP, T0 - T4), and quality plus taper period (QTP, T4 - T12). The LMT intensity of T4 and T12 were significantly higher than T0. We conclude that LMT is modified due to swimming training and can be used for training prescription and detection of aerobic capacity alterations during a season...
"Resposta do teste de lactato mínimo à 12 semanas de treinamento de natação." Apesar da comum utilização do teste de lactate mínimo (LMT) no treinamento, a sensibilidade da sua intensidade permanece controversa. O objetivo do presente estudo foi verificar alterações da intensidade do LMT em nadadores durante 12 semanas de treinamento. Oito nadadores foram submetidos à três avaliações LMT: começo da temporada, T0; após quatro, T4; e doze semanas, T12. O LMT consistiu em nadar 200m em esforço máximo, e após oito minutos de repouso passivo, cinco estágios incrementais de 200m. As intensidades dos estágios incrementais foram definidas subjetivamente ("muito fraco," "fraco," "moderado," "forte" e "máximo"). O treinamento foi dividido em dois blocos de periodização: período de treinamento de endurance (ETP, T0 - T4), e período específico mais polimento (QTP, T4 - T12). A intensidade do LMT em T4 e T12 foi significantemente maior que T0. Concluímos que o LMT é modificado com o treinamento de natação e pode ser usado na prescrição de treinamento e detecção de alterações da capacidade aeróbia durante a temporada...
"La respuesta del test de lactato mínimo de 12 semanas de entrenamiento de natación." A pesar de la utilización de lo test de lactato mínimo (LMT) en el entrenamiento, la respuesta de su intensidad sigue siendo controvertido. El objetivo de este estudio fue investigar los cambios en la intensidad de LMT en nadadores durante 12 semanas de entrenamiento. Ocho nadadores fueron sometidos a tres evaluaciones LMT: comienzo de la temporada, T0; después de las cuatro, T4; y doce semanas T12. El LMT consistió en 200m natación de máximo esfuerzo, y después de ocho minutos de descanso pasivo, cinco etapas incrementales de 200m. Las intensidades de las fases incrementales fueron definidos subjetivamente ("muy débil," "débil," "moderada," "fuerte" y "máxima"). La formación se dividió en dos bloques de periodización: período de entrenamiento de endurance (ETP, T0 - T4), y período específico más pulido (QTP, T4 - T12). La intensidad del LMT en T4 y T12 fue significativamente mayor que T0. Concluimos que el LMT es modificado con el entrenamiento de natación y puede ser utilizado en la prescripción de al entrenamiento y la detección de cambios en la capacidad aeróbica durante la temporada...
