Open AccessThe immediate effects of a single bout of aerobic exercise on oral glucose tolerance across the glucose tolerance continuum
Author(s) -
Knudsen Sine H.,
Karstoft Kristian,
Pedersen Bente K.,
Hall Gerrit,
Solomon Thomas P. J.
Publication year - 2014
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12114
Subject(s) - postprandial , medicine , endocrinology , impaired glucose tolerance , glycemic , aerobic exercise , glucose tolerance test , glucagon , area under the curve , insulin , type 2 diabetes , diabetes mellitus , insulin resistance
We investigated glucose tolerance and postprandial glucose fluxes immediately after a single bout of aerobic exercise in subjects representing the entire glucose tolerance continuum. Twenty‐four men with normal glucose tolerance ( NGT ), impaired glucose tolerance ( IGT ), or type 2 diabetes (T2D; age: 56 ± 1 years; body mass index: 27.8 ± 0.7 kg/m 2 , P > 0.05) underwent a 180‐min oral glucose tolerance test ( OGTT ) combined with constant intravenous infusion of [6,6‐ 2 H 2 ]glucose and ingestion of [U‐ 13 C]glucose, following 1 h of exercise (50% of peak aerobic power) or rest. In both trials, plasma glucose concentrations and kinetics, insulin, C‐peptide, and glucagon were measured. Rates (mg kg −1 min −1 ) of glucose appearance from endogenous ( R aEndo ) and exogenous (oral glucose; R a OGTT ) sources, and glucose disappearance ( R d ) were determined. We found that exercise increased R aEndo , R aOGTT , and R d (all P < 0.0001) in all groups with a tendency for a greater (~20%) peak R aOGTT value in NGT subjects when compared to IGT and T2D subjects. Accordingly, following exercise, the plasma glucose concentration during the OGTT was increased in NGT subjects ( P < 0.05), while unchanged in subjects with IGT and T2D. In conclusion, while a single bout of moderate‐intensity exercise increased the postprandial glucose response in NGT subjects, glucose tolerance following exercise was preserved in the two hyperglycemic groups. Thus, postprandial plasma glucose responses immediately following exercise are dependent on the underlying degree of glycemic control.