title: Assessment of maximal lactate steady state during treadmill exercise in SHR.
abstract: BACKGROUND
  Spontaneously hypertensive rats (SHR) are one of the main animal models used for studying the effects of exercise on hypertension. Therefore, the determination of adequate intensity has been essential for secure and optimized exercise prescriptions concerning hypertensive subjects. This study aimed to identify the MLSS in SHR by using a treadmill test to improve the protocols and further prescriptions of exercise intensity.
  
  
  RESULTS
  In order to carry out this determination, SHR (n = 10) animals (~17.5 weeks; 227.4 ± 29.3 g; 172.4 ± 8.1 mmHg systolic blood pressure) were divided into two groups (G1 n = 5; G2 n = 5). Rats underwent a test with three different velocities to determine the MLSS. The MLSS was considered as the highest effort intensity where the blood lactate did not vary more than 1 mmol.L-1 from the 10th to the 25th minute. The MLSS was reached at a velocity of 20 m.min-1 with 3.8 ± 0.5 mmol.L-1 of lactate for G1. Additionally, the results were validated in G2. However, when the test was applied at 25 m.min-1, there was no stabilization of BLC in G1 and G2.
  
  
  CONCLUSIONS
  In this study it was possible to identify the MLSS in SHR rats, which is an excellent evaluation tool to control exercise intensity. These data are of considerable importance in studies using physical exercise as a means of research in hypertension and may lead to the intensity of exercise being prescribed more appropriately.
authors.affiliation: Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN, Quadra 916, Módulo B, Brasília, DF, 70790-160, Brazil.
authors.forename: Jeeser Alves
authors.initials: JA
authors.lastname: Almeida
authors.forename: Bernardo de Assis
authors.initials: Bde A
authors.lastname: Petriz
authors.forename: Clarissa Pedrosa
authors.initials: CP
authors.lastname: da Costa Gomes
authors.forename: Rinaldo Wellerson
authors.initials: RW
authors.lastname: Pereira
authors.forename: Octávio Luiz
authors.initials: OL
authors.lastname: Franco
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D004195:Disease Models, Animal; D005081:Exercise Therapy; D005260:Female; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D019344:Lactic Acid / Q000378:metabolism*; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D013997:Time Factors
chemical_list: D015415:Biomarkers; D019344:Lactic Acid