The Effect of Mode of Transport on Intraindividual Variability in Glycemic and Insulinemic Response Testing

Abstract

The effect of light- to moderate-intensity exercise, such as that used as a mode of transport, on glycemic response testing is unclear. The aim was to investigate the effect of acute exercise (walking and cycling), simulated to act as a mode of transport, prior to glycemic response testing on the intraindividual variability of blood glucose and insulin. A total of 11 male participants visited the laboratory four times. Initially, they undertook a maximum oxygen uptake and two submaximal exercise tests. For the other three visits, they either rested (25 min), cycled, or walked 5 km followed by a 2-hr glycemic response test after consuming a glucose drink (50 g of available carbohydrate). The mean coefficient of variation of each transport group was below the International Organization for Standardization cutoff of 30%. The highest mean coefficient of variation of glucose area under the curve (AUC) was between the rest and the walking trials (30%) followed by walking and cycling (26%). For insulin AUC, the highest mean coefficient of variation was between walking and cycling (28%) followed by rest and walking (24%). The lowest glucose AUC and insulin AUC were between rest and cycling (25% and 14%, respectively). This study did not find differences (p > .05) between the conditions for glucose AUC (at 120 min, rest: 134.5 ± 104.6 mmol/L; walking: 115.5 ± 71.7 mmol/L; and cycling: 142.5 ± 75 mmol/L) and insulin AUC (at 120 min, rest: 19.45 ± 9.12 μmol/ml; walking: 16.49 ± 8.42 μmol/ml; and cycling: 18.55 ± 9.23 μmol/ml). The results indicate no difference between the tests undertaken; however, further research should ensure the inclusion of two rest conditions.