The Metabolic Effects of Ultra-endurance Exercise and Training Under Low or High Glycaemic Index-carbohydrate Diets.

Inclusion Criteria: * Informed consent obtained * Male or female aged 18-65 years (both inclusive) * Otherwise healthy (as judged by premedical questionnaire) and participating in regular training (volume in training \>10 h training per week) and participating in endurance events and/or VO2max \> 55 ml.kg-1.min-1. Exclusion Criteria: * Receipt of any investigational medicinal product within 1 month prior to screening in this trial * Haemoglobin \<8.0 mmol/L (male) or \<7.0 mmol/L (female). * Systemic (oral or i.v.) corticosteroids, monoamine oxidase (MAO) inhibitors, non-selective beta-blockers, growth hormone and non-routine vitamins and herbal products. Furthermore, thyroid hormones are not allowed unless the use of these has been stable during the past 3 months. * Suffer from or history of a life-threatening disease (i.e. cancer judged not to be in full remission except basal cell skin cancer or squamous cell skin cancer), or clinically severe diseases that directly influence the study results, as judged by the Investigator. This does not prohibit the participation of patients taking medications that influences their metabolism (e.g. statin) or cardio- respiratory system (e.g. asthma spray) as long as the therapy is stable and is not adapted throughout the run of the trial. Furthermore, it does not exclude patients how have coeliac disease (or similar diseases or allergies), as long as the disease is stable, and patients are able to stay on their specific (e.g.) gluten-…