title: The effect of training and epinephrine infusion on ratings of perceived exertion (RPE).
abstract: Seven untrained males (mean age [+/-SD] = 25.6+/-3.9 yr, mean ht = 177.0+/-5.9 cm, mean wt = 65.8+/-7.4 kg) completed a 6-week exercise program (cycle ergometer). Prior to training, and at the end of each week of training, each subject performed a 20 min constant-power exercise test (absolute power was the same each week). At the end of the six week training program (within a few days), an additional 20 min constant-power test was performed, during which epinephrine was infused at a rate of 100 ng x kg(-1) x min(-1) over the final 10 min of exercise. Training significantly (P<0.05) reduced end-exercise ratings of perceived exertion (RPE), plasma epinephrine concentration [Epi], plasma norepinephrine concentration [NE], blood lactate concentration [La-], minute ventilation (V(E)), heart rate (HR), and blood glucose concentration [Glc]. Epinephrine infusion failed to increase RPE despite significant (p < 0.05) increases in [Epi], [La-], V(E) and [Glc]. Therefore, the present data indicate that RPE during exercise is not causally related to changes in plasma [Epi]. It also appears that modest changes in plasma [NE], blood [La-], V(E) and blood [Glc] during constant-power cycle ergometry (as observed during Epi infusion) do not impact RPE.
authors.affiliation: Exercise Physiology Laboratory, General Clinical Research Center, Charlottesville, VA 22903, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Womack
authors.forename: S E
authors.initials: SE
authors.lastname: Davis
authors.forename: J Y
authors.initials: JY
authors.lastname: Weltman
authors.forename: J
authors.initials: J
authors.lastname: Blumer
authors.forename: E J
authors.initials: EJ
authors.lastname: Barrett
authors.forename: G A
authors.initials: GA
authors.lastname: Gaesser
authors.forename: A
authors.initials: A
authors.lastname: Weltman
mesh_terms: D000322:Adrenergic Agonists / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D000316:Adrenergic alpha-Agonists / Q000097:blood; D000328:Adult; D000704:Analysis of Variance; D001786:Blood Glucose / Q000032:analysis; D004837:Epinephrine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005080:Exercise Test; D005081:Exercise Therapy; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007262:Infusions, Intravenous; D007773:Lactates / Q000097:blood; D008297:Male; D008451:Maximal Voluntary Ventilation / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010465:Perception / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects / Q000502:physiology*; D011659:Pulmonary Gas Exchange / Q000187:drug effects / Q000502:physiology; D012119:Respiration / Q000187:drug effects / Q000502:physiology
chemical_list: D000322:Adrenergic Agonists; D000316:Adrenergic alpha-Agonists; D001786:Blood Glucose; D007773:Lactates; D009638:Norepinephrine; D004837:Epinephrine