Sustained swimming at low velocity following a bout of exhaustive exerciseenhances metabolic recovery in rainbow trout

Citation
Cl. Milligan et al., Sustained swimming at low velocity following a bout of exhaustive exerciseenhances metabolic recovery in rainbow trout, J EXP BIOL, 203(5), 2000, pp. 921-926
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology,"Experimental Biology
Journal title
JOURNAL OF EXPERIMENTAL BIOLOGY
ISSN journal
0022-0949 → ACNP
Volume
203
Issue
5
Year of publication
2000
Pages
921 - 926
Database
ISI
SICI code
0022-0949(200003)203:5<921:SSALVF>2.0.ZU;2-1
Abstract
Sustained swimming al: 0.9 BL s(-1), where BL is fork body length, followin g a bout of exhaustive exercise enhanced recovery of metabolite;and acid-ba se status in rainbow trout compared with fish held in still water. The most striking effect of an active recovery was a total absence of the elevation cortisol concentration typically associated with exhaustive exercise. In f ish swimming at 0.9 BL s(-1), plasma cortisol levels averaged 20-25 ng ml(- 1) throughout the 6h recovery period. In contrast, plasma cortisol increase d to a peak level of 128.4+/-11.2 ng ml(-1) (mean +/- S.E.M., N=6) in fish recovering in still water. Muscle glycogen was completely resynthesized and lactate cleared within 2h of exercise in swimming fish compared with more than 6h required in the fish held in still water. Similarly, blood lactate level and acid-base status were restored more quickly in the swimming fish. These observations suggest that the prolonged recovery usually associated with exhaustive exercise in rainbow trout is due to elevations in plasma co rtisol concentration and that the stimulus for cortisol release is not exer cise ger se, but rather postexercise inactivity.