The effects of high-fat overfeeding with and without acute exercise on indices of arterial stiffness

Objective: To examine the effects of high-fat overfeeding, with and without acute exercise, on indices of arterial stiffness in young healthy adults. Hypothesis: High-fat overfeeding will increase arterial stiffness during a 75g oral glucose tolerance test (OGTT), and this rise will be blunted by acute exercise. Methods: Young healthy adults (n=18, 9F; age 24.3±3.9 y; BMI 24.1±3.5 kg/m 2 ; mean ± SD) completed a control diet (CON) for one day. Participants then completed one day of high-fat overfeeding (HFOF; 180% of estimated energy intake [eEI], 65% kcal from fat) or HFOF plus exercise (HFOF+Ex, low-intensity exercise in the afternoon until 25% of eEI was expended) with a ≥5-day washout between HFOF trials in a randomized crossover. To match net energy availability between HFOF conditions, exercise energy expenditure was refed during HFOF+Ex. The morning following each condition, participants completed a 120min, 75g OGTT. At fasting, 60, and 120 minutes following the OGTT, we measured carotid-femoral pulse wave velocity (PWV) and augmentation index at 75 bpm (AIx75) to assess arterial stiffness and aortic waveforms respectively. Results: PWV did not change differently over time across diet conditions (p=0.610) or change over time (p=0.147). PWV was, however, reduced throughout the OGTT following HFOF+Ex compared to CON (p=0.0497; difference: 0.3 ± 0.4 m/s, mean ± SD). Compared to fasting, AIx75 was reduced at 60 min (p=0.0004) and 120 min (p=0.028) without differences between 60 and 120 min (p=0.385). AIx75 was also not different between CON and HFOF (p=0.960), although it was higher after HFOF+Ex compared to CON (p=0.041) and HFOF alone (p=0.009). Conclusions: HFOF does not significantly alter fasting or postprandial indices of arterial stiffness in young adults. However, low intensity exercise 18 hours before an OGTT improves indices of arterial stiffness and aortic waveforms. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.