title: Adaptation of insulin-resistance indicators to a repeated bout of eccentric exercise in human skeletal muscle.
abstract: This study determined whether disrupted glucose and insulin responses to an oral glucose-tolerance test (OGTT) induced by eccentric exercise were attenuated after a repeated bout. Female participants (n = 10, age 24.7 +/- 3.0 yr, body mass 64.9 +/- 7.4 kg, height 1.67 +/- 0.02 m, body fat 29% +/- 2%) performed 2 bouts of downhill running (DTR 1 and DTR 2) separated by 14 d. OGTTs were administered at baseline and 48 hr after DTR 1 and DTR 2. Maximum voluntary isometric quadriceps torque (MVC), subjective soreness (100-mm visual analog scale), and serum creatine kinase (CK) were assessed pre-, post-, and 48 hr post-DTR 1 and DTR 2. Insulin and glucose area under the curve (38% +/- 8% and 21% +/- 5% increase, respectively) and peak insulin (44.1 +/- 5.1 vs. 31.6 +/- 4.0 muU/ml) and glucose (6.5 +/- 0.4 vs. 5.5 +/- 0.4 mmol/L) were elevated after DTR 1, with no increase above baseline 48 hr after DTR 2. MVC remained reduced by 9% +/- 3% 48 hr after DTR 1, recovering back to baseline 48 hr after DTR 2. Soreness was elevated to a greater degree 48 hr after DTR 1 (48 +/- 6 vs. 13 +/- 3 mm), with a tendency for greater CK responses 48 hr after DTR 1 (813 +/- 365 vs. 163 +/- 43 U/L, p = .08). A novel bout of eccentric exercise confers protective effects, with subsequent bouts failing to elicit disruptions in glucose and insulin homeostasis.
authors.affiliation: Dept. of Kinesiology and Health Promotion, Troy University, Troy, AL, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Green
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Doyle
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ingalls
authors.forename: Dan
authors.initials: D
authors.lastname: Benardot
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Rupp
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Corona
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism; D005080:Exercise Test; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007537:Isometric Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology* / Q000503:physiopathology; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin; D003402:Creatine Kinase