This study examined the physiological effect of reduced plasma @entity701 (C) during prolonged exercise in @entity1 . The effects of normal C (NC) were compared with @entity4235 -induced low C (LC) on plasma substrate availability and the respiratory exchange ratio during 2 h of exercise at approximately 60% peak O2 consumption in nine subjects. The C responses were compared with preexercise (Pre) levels and with a rest day (Con). At rest, C was attenuated by approximately 70% for LC compared with NC. At rest, plasma @entity413 , @entity880 , @entity653 , @entity4322 , @entity493 , branched-chain @entity1522 , insulin, glucagon, @entity2124 , @entity1425 , and @entity1063 were similar under LC and NC (P > 0.05). During exercise under NC, plasma C increased compared with Pre, whereas it remained unchanged during LC. During NC, plasma C was elevated at 90 min (compared with Con) and at 120 min (compared with Con and Pre). During exercise, plasma @entity413 decreased to the same extent and @entity880 was similar under both conditions, whereas plasma @entity653 , @entity4322 , @entity493 , and branched-chain @entity1522 were higher (P < 0.01) under NC. Plasma insulin declined (P = 0.01) to a greater extent under LC, whereas @entity2124 , @entity1425 , and @entity1063 tended to be higher (0.05 </= P </= 0.10). Plasma glucagon increased under both conditions (P < 0.01). The respiratory exchange ratio did not differ between conditions. We conclude that, during exercise, 1) C accelerates lipolysis, ketogenesis, and proteolysis; 2) under LC, glucoregulatory hormone adjustments maintain @entity413 homeostasis; and 3) LC does not alter whole body substrate utilization or the ability to complete 2 h of moderate exercise.

Metabolic effects of low XXXX during exercise in @entity1 .

@entity1 :: ('9606', 'Species') :: ['humans'] @entity4235 :: ('MESH:D008797', 'Chemical') :: ['metyrapone'] @entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity1425 :: ('MESH:D004837', 'Chemical') :: ['epinephrine'] @entity4322 :: ('MESH:D020155', 'Chemical') :: ['beta-hydroxybutyrate'] @entity653 :: ('MESH:D005990', 'Chemical') :: ['glycerol'] @entity2124 :: ('2688', 'Gene') :: ['growth hormone'] @entity701 :: ('MESH:D006854', 'Chemical') :: ['cortisol'] @entity880 :: ('MESH:D019344', 'Chemical') :: ['lactate'] @entity1063 :: ('MESH:D009638', 'Chemical') :: ['norepinephrine'] @entity493 :: ('CHEBI:16449', 'Chemical') :: ['alanine'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose']
@entity701 :: (MESH:D006854,Chemical) :: ['cortisol']
