Author(s): JIN, Z., LI, J., THACKRAY, A., KING, J., STENSEL, D., Institution: LOUGHBOROUGH UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 1344

INTRODUCTION:
Oxyntomodulin (OXM) is an appetite-related gut hormone, implicated in weight management through its roles in reducing energy intake, and increasing energy expenditure. This study examined 1) the effect of acute moderate-intensity continuous running on oxyntomodulin concentrations; and 2) whether exercise-induced oxyntomodulin fluctuations are correlated with subsequent energy intake.
METHODS:
20 healthy-weight individuals (10 men, 10 women; age: 25 ± 4 years; BMI: 22 ± 2 kg·m-2 (mean ± SD)) completed two, 3.5-hour trials, exercise (EX) and control (CON), in a randomised order. Participants were required to fast overnight and engaged in a 60-minute treadmill run at 70% of their peak oxygen uptake (EX) or rested (CON) for the first hour of each trial. Participants then remained in the lab for an additional 2.5 hours and were served an ad libitum pasta meal one-hour after completion of exercise/rest i.e., at 2 hours. Blood samples were collected to measure oxyntomodulin concentrations at baseline (t = 0 minute), immediately after-exercise/rest (t = 60 minutes), and every 30 minutes thereafter up to 210 minutes (3.5 hours).
RESULTS:
Linear mixed model analysis indicated no significant main effect of exercise on OXM concentrations (p = 0.227). However, a significant trial by time interaction was noted (p = 0.041). At t = 60 minutes, control was associated with a decrease in OXM concentrations relative to baseline, while the exercise trial exhibited an increasing trend. No significant differences were observed in time-averaged total area under the curve (tAUC) or incremental area under the curve (iAUC) for OXM between the exercise and control trials. Absolute energy intake (EI) remained unaffected by exercise. However, exercise led to a significant reduction in relative EI (p < 0.001) when considering the energy expended during exercise. No significant correlations were identified between OXM tAUC or iAUC and absolute EI.
CONCLUSION:
Acute moderate-intensity exercise transiently modulates OXM concentrations. However, these exercise-induced alterations in OXM do not last and do not translate into changes in subsequent energy intake, at least in the short term.