Training & Testing
371
Understanding the Meaning of Lactate Threshold in Resistance Exercises
Authors
M. V. Garnacho-Castaño1, R. Dominguez2, J. L. Maté-Muñoz2
Affiliations
1
Key words ▶ cardiorespiratory response ● ▶ metabolic response ● ▶ mechanical fatigue ● ▶ cycle ergometer ● ▶ half squat ●
Abstract
Physiology and Immunology, University of Barcelona, Barcelona, Spain Physical Activity and Sports Science, Alfonso X El Sabio University, Villanueva de la Cañada, Spain
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This study compares acute cardiorespiratory, metabolic, mechanical and rating of perceived effort (RPE) responses to 2 different prolonged constant-load exercises, half-squat (HS) and cycle ergometry, performed at a workload corresponding to the lactate threshold (LT). A total of 18 healthy subjects completed 5 exercise tests separated by 48 h rest periods: an incremental cycle ergometer test, a constant-load cycle ergometer test at LT intensity, a one-repetition maximum (1RM) HS test, an incremental HS test and a constant-load HS test at LT intensity. In both constant-load tests, cardiorespiratory, metabolic and RPE data were recorded. Mechanical responses before and after each test were
Introduction accepted after revision October 28, 2014 Bibliography DOI http://dx.doi.org/ 10.1055/s-0034-1398495 Published online: February 13, 2015 Int J Sports Med 2015; 36: 371–377 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0172-4622 Correspondence Dr. Manuel Vicente GarnachoCastaño Physiology and Immunology University of Barcelona C/Diagonal N°643 08019 Barcelona Spain Tel.: + 34/606/275 392 Fax: + 34/606/275 392 [email protected]
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Knowledge of the acute physiological and mechanical response to resistance training (RT) is critical for understanding the adaptation mechanisms produced by different stimuli [12]. The main variables traditionally used to define RT stimuli are the type and order of exercises, the number of exercise repetitions and sets, the workload, and the rest period [27]. The intensity of training exercise has been generally accepted as the most determining factor for producing changes in acute cardiorespiratoy responses to exercises [1]. Recent research efforts have focused on incremental resistance tests [14, 39] designed to identify the point of transition between aerobic and anaerobic exercise, known as the lactate threshold (LT) [11]. The LT is defined as the work intensity during incremental exercise at which blood lactate concentrations increase exponentially, coinciding with eventual muscle fatigue [40]. Furthermore, the LT is considered a valid indica-
assessed in terms of jump height and mean power measured in a counter movement jump (CMJ) test. In both exercises, cardiorespiratory and metabolic responses stabilized, though cardiorespiratory responses were significantly greater for cycle ergometry (P
371
Understanding the Meaning of Lactate Threshold in Resistance Exercises
Authors
M. V. Garnacho-Castaño1, R. Dominguez2, J. L. Maté-Muñoz2
Affiliations
1
Key words ▶ cardiorespiratory response ● ▶ metabolic response ● ▶ mechanical fatigue ● ▶ cycle ergometer ● ▶ half squat ●
Abstract
Physiology and Immunology, University of Barcelona, Barcelona, Spain Physical Activity and Sports Science, Alfonso X El Sabio University, Villanueva de la Cañada, Spain
▼
This study compares acute cardiorespiratory, metabolic, mechanical and rating of perceived effort (RPE) responses to 2 different prolonged constant-load exercises, half-squat (HS) and cycle ergometry, performed at a workload corresponding to the lactate threshold (LT). A total of 18 healthy subjects completed 5 exercise tests separated by 48 h rest periods: an incremental cycle ergometer test, a constant-load cycle ergometer test at LT intensity, a one-repetition maximum (1RM) HS test, an incremental HS test and a constant-load HS test at LT intensity. In both constant-load tests, cardiorespiratory, metabolic and RPE data were recorded. Mechanical responses before and after each test were
Introduction accepted after revision October 28, 2014 Bibliography DOI http://dx.doi.org/ 10.1055/s-0034-1398495 Published online: February 13, 2015 Int J Sports Med 2015; 36: 371–377 © Georg Thieme Verlag KG Stuttgart · New York ISSN 0172-4622 Correspondence Dr. Manuel Vicente GarnachoCastaño Physiology and Immunology University of Barcelona C/Diagonal N°643 08019 Barcelona Spain Tel.: + 34/606/275 392 Fax: + 34/606/275 392 [email protected]
▼
Knowledge of the acute physiological and mechanical response to resistance training (RT) is critical for understanding the adaptation mechanisms produced by different stimuli [12]. The main variables traditionally used to define RT stimuli are the type and order of exercises, the number of exercise repetitions and sets, the workload, and the rest period [27]. The intensity of training exercise has been generally accepted as the most determining factor for producing changes in acute cardiorespiratoy responses to exercises [1]. Recent research efforts have focused on incremental resistance tests [14, 39] designed to identify the point of transition between aerobic and anaerobic exercise, known as the lactate threshold (LT) [11]. The LT is defined as the work intensity during incremental exercise at which blood lactate concentrations increase exponentially, coinciding with eventual muscle fatigue [40]. Furthermore, the LT is considered a valid indica-
assessed in terms of jump height and mean power measured in a counter movement jump (CMJ) test. In both exercises, cardiorespiratory and metabolic responses stabilized, though cardiorespiratory responses were significantly greater for cycle ergometry (P
