Maximal lactate steady state in swimming rats by a body density-related method of workload quantification

Author(s)

Masselli dos Reis, Ivan Gustavo ; de Araujo, Gustavo Gomes ; Gobatto, Claudio Alexandre

• Document type: Journal article
• Source: COMPARATIVE EXERCISE PHYSIOLOGY; v. 7, n. 4, p. 6-pg., 2010-11-01.

Abstract

The impact of body density (BD) on an animal's capacity to sustain a workload is important in the accuracy of evaluating swimming exercise in rats and the associated training protocols. The aim of this study was to quantify the influence of BD the maximal lactate steady-state (MLSS) workload in swimming rats. The BD of ten 90-day-old rats and sixteen 120-day-old rats was determined by underwater weighing, and their aerobic capacity was determined by the MLSS test. The MLSS blood concentration values were 4.11 +/- 0.96 mmol 1(-1) in the 90-day-old rats and 4.81 +/- 1.49 mmol 1(-1) in the 120-day-old rats. There was no significant (P > 0.05) difference between these values. The older rats were more dense (P < 0.001) and showed a significantly increased (P < 0.001) absolute effort and relative-to-body-weight effort to keep themselves on the water surface when compared with the younger rats. BD can significantly affect an animal's capacity to sustain work within this age range, and individual fluctuation in effort should be determined to avoid mistakes when interpreting the results. This is particularly important in longitudinal studies in which the intervention or ageing process can modify the animal's body composition. Our results quantify the effects of BD on the performance of rats in the MLSS test. (AU)

• FAPESP's process: 08/03445-5 - Analysis of the force and swimming pattern parameters in control and obese rats from a signs acquisition system, in tethered swimming. influence of the exercise intensity and body density
• Grantee: Ivan Gustavo Masselli dos Reis
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 11/08284-2 - Acute effect of exercise in the intensity of maximal lactate steady state on protein and mRNA expressions of HIF-1±, MCTs 1 e 4 e PGC-1±, in heart, hepatic and skeletal muscle of swimming rats
• Grantee: Ivan Gustavo Masselli dos Reis
• Support Opportunities: Scholarships in Brazil - Doctorate