This study aims to investigate the effects of post-exercise and pre-sleep exogenous ketosis via oral ketone ester supplementation during a 5 week simulated altitude training camp.

Altitude training camps, where you train at sea level but live at altitude, have become a popular way for athletes to prepare for upcoming races or events. The main aim of such training camps is to benefit from the adaptations following prolonged hypoxic exposure (increased EPO concentrations leading to an increase in oxygen carrying capacity in the blood). Recently, ketone bodies have been shown to cause similar adaptations. Therefore, this study aims to investigate whether the combination of exogenous ketosis and an altitude training camp is more beneficial compared to an altitude training camp on its own.

Participants will follow a 5 week simulated altitude training camp where they spend 75 hours per week at altitude (2000-3000 meters), while taking ketone or placebo supplements after every training sessions and before going to sleep. During these 5 weeks, they will adhere to a prescribed training plan, consisting of 5 to 7 training sessions per week. Before, after and 1 week after the training camp, their exercise performance, EPO concentrations, hemoglobin mass and VO2max will be tested.

Inclusion Criteria:

• Physically fit and regularly involved in physical activity (2-5h per week)
• Good health status confirmed by a medical screening
• Non-smoking

Exclusion Criteria:

• Any kind of injury/pathology that is a contra-indication to perform high-intensity exercise
• Any kind of injury/pathology that is a contra-indication for exposure to hypoxia
• Ongoing pregnancy or breastfeeding
• intake of any medication or nutritional supplement that is proven to affect exercise performance during the last month prior to the start of the study
• Involvement in elite athletic training at a semi-professional or professional level
• Exposure to altitudes higher than 1500 m during the 3 months prior to the start of the study
• Blood ferritin levels below 30 ng/mL
• Current participation in another research trial
• Any other argument to believe that the subject is unlikely to succesfully complete the full study protocol

Participants and investigators are blinded from the experimental condition (KE or CON). Supplements are provided in non transparent tubes and the control supplement is identical in taste and viscosity to the ketone supplement.