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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Time of day effects on aerobic capacity, muscle glycogen content and performance assessment in swimming rats

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Beck, W. R. [1, 2] ; Ribeiro, L. F. P. [1, 3] ; Scariot, P. P. M. [1] ; dos Reis, I. G. M. [1, 2] ; Gobatto, C. A. [1]
Total Authors: 5
[1] Univ Estadual Campinas, Sch Appl Sci, Lab Appl Sport Physiol, BR-13484350 Sao Paulo - Brazil
[2] Univ Estadual Campinas, Fac Phys Educ, Campinas, SP - Brazil
[3] Univ Estadual Santa Cruz, Dept Hlth Sci, Santa Cruz - Bahamas
Total Affiliations: 3
Document type: Journal article
Source: SCIENCE & SPORTS; v. 29, n. 6, p. 319-323, DEC 2014.
Web of Science Citations: 3

Objective. The aims of this study were to analyze the time of day effects on aerobic capacity, time to exhaustion at this intensity and skeletal muscle glycogen concentration in swimming rats. Methods. Initially, 80 animals were divided in four groups handled and tested at 12:00 and 20:00 h and subjected to a lactate minimum test. For 12:00 and 20:00 h, the lactate minimum intensity was successfully determined in 65 vs 85% of the animals, respectively, and no significant differences (P=0.15) were found between groups for this variable (4.95 +/- 0.40 vs 4.83 +/- 0.48% body weight, respectively). Forty-eight hours after, exercised groups (at 12:00 h or 20:00 h) performed an exhaustive swim bout at lactate minimum intensity. Results. Time to exhaustion was significantly greater (P=0.03) for rats exercised in the dark vs light period (108.89 +/- 46.33 vs 77.96 +/- 30.81 min, respectively). In addition, higher skeletal muscle glycogen concentrations were found in control group at 20:00 h when compared to all other groups, probably playing an important rote on time to exhaustion. These results suggest that although rat's aerobic capacity is not affected by the time of day, swimming performance is improved in the dark when compared to light period. (C) 2014 Elsevier Masson SAS. All rights reserved. (AU)

FAPESP's process: 11/13226-1 - Ergogenic response of melatonin during the nadir and acrophase of spontaneous activity: consequences on IKK/Nf-kB via
Grantee:Wladimir Rafael Beck
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 10/13377-7 - Effects of light and time of day of swimming exercise until exhaustion at lactate minimum intensity on biochemistry and hematologic responses of rats
Grantee:Wladimir Rafael Beck
Support type: Scholarships in Brazil - Master