title: Acute postexercise effects of concentric and eccentric exercise on glucose tolerance.
abstract: Impaired glucose tolerance was shown to be present 48 hr following muscle-damaging eccentric exercise. We examined the acute effect of concentric and muscle-damaging eccentric exercise, matched for intensity, on the responses to a 2-hr 75-g oral glucose tolerance test (OGTT). Ten men (27 ± 9 years, 178 ± 7 cm, 75 ± 11 kg, VO₂max: 52.3 ± 7.3 ml · kg⁻¹ · min⁻¹) underwent three OGTTs after an overnight 12 hr fast: rest (control), 40-min (5 × 8-min with 2-min interbout rest) of concentric (level running, 0%, CON) or eccentric exercise (downhill running, -12%, ECC). Running intensity was matched at 60% of maximal metabolic equivalent. Maximal isometric force of m. quadriceps femoris of both legs was measured before and after the running protocols. Downhill running speed was higher (level: 9.7 ± 2.1, downhill: 13.8 ± 3.2 km · hr⁻¹, p < .01). Running protocols had similar VO₂max (p = .59), heart rates (p = .20) and respiratory exchange ratio values (p = .74) indicating matched intensity and metabolic demands. Downhill running resulted in higher isometric force deficits (level: 3.0 ± 6.7, downhill: 17.1 ± 7.3%, p < .01). During OGTTs, area-under-the-curve for plasma glucose (control: 724 ± 97, CON: 710 ± 77, ECC: 726 ± 72 mmol · L⁻¹ · 120 min, p = .86) and insulin (control: 24995 ± 11229, CON: 23319 ± 10417, ECC: 21842 ± 10171 pmol · L⁻¹ · 120 min, p = .48), peak glucose (control: 8.1 ± 1.3, CON: 7.7 ± 1.2, ECC: 7.7 ± 1.1 mmol · L⁻¹, p = .63) and peak insulin levels (control: 361 ± 188, CON: 322 ± 179, ECC: 299 ± 152 pmol · L⁻¹, p = .30) were similar. It was concluded that glucose tolerance and the insulin response to an OGTT were not changed immediately by muscle-damaging eccentric exercise.
authors.affiliation: Dept. of Sport and Exercise Sciences, University of Chichester, Chichester, UK.
authors.forename: Matthew David
authors.initials: MD
authors.lastname: Cook
authors.forename: Stephen David
authors.initials: SD
authors.lastname: Myers
authors.forename: John Stephen Michael
authors.initials: JS
authors.lastname: Kelly
authors.forename: Mark Elisabeth Theodorus
authors.initials: ME
authors.lastname: Willems
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015444:Exercise; D018149:Glucose Intolerance / Q000097:blood / Q000209:etiology* / Q000378:metabolism; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D009043:Motor Activity; D010101:Oxygen Consumption; D005082:Physical Exertion; D052097:Quadriceps Muscle / Q000378:metabolism*; D012420:Running; D013312:Stress, Physiological; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin