Tijdrit prestaties van verschillende voedingsproducten bij gezonde vrijwilligers.

Rationale: Differences in available carbohydrates (CHOs) in food products lead to differences in the glycaemic index (GI) of these foods. Furthermore, different studies show that the intake of low-GI meals before the onset of exercise induce a lower glucose and insulin response at rest, but higher blood glucose concentration and higher free fatty acids (FFA) concentration at the end of exercise. This eventually leads to a longer time to exhaustion after the intake of a low-GI meal in comparison to the intake of a high-GI meal. This effect is especially found in endurance athletes. During exercise, low-GI food intake has beneficial effects on performance in comparison to high-GI food intake. These effects can be addressed to the maintenance of blood glucose levels during exercise, increase of FFA concentrations and reducing exercise respiratory exchange ratio (RER) values. During the recovery stage, which occurs after exercise, the body restores homeostasis and this helps the body to adapt to physiological stress. It is important to enhance recovery after exercise much as possible. Part of the recovery phase includes the restoration of glycogen stores. The consumption of moderate or high-GI CHOs has shown to induce a greater effect on glycogen restoration compared to low-GI CHO ingestion.



Objective: To study the effect of 2 different CHO sources (Snelle Jelle – a grain based food product – and a banana), which are expected to have different GIs, and water on time trial performance of healthy, male, trained cyclists.



Study design: The study will be executed conform a randomized; cross-over, reference-controlled study design.



Study population: 11 healthy trained male cyclists/triathletes, aged 18-40 years, will be recruited.



Intervention: Participants will either receive Snelle Jelle ‘Ontbijtkoek’ or a banana accompanied with a glass of water or only water, randomly on 3 separate test days.



Main study parameters/endpoints: The main study parameter is the time trial performance in response to the test products.

The hypothesis is that the test food with the lower glycemic response exerts a more positive effect on exercise performance than the test food with a higher glycemic response.

Participants are required to complete a time trial test of 1 hour on each test day. They will be asked to consume one of 3 test products (a different product at random on each test day, 3 test days in total) at -30, 30 and 45 minutes relative to the start of the time trial test.

Participants will receive a "Ontbijtkoek" (with water), banana (with water) or water alone (control condition) randomly on 3 separate test days.