Sportspersons who train at heights (above 3500 m) must expect increased BMR (basic metabolic rate) by up to 17%. In addition, such height will entail hypoxia (oxygen deficiency) due to lower partial pressure of the oxygen leading to increase in the GLUT4 transporter (glucose type 4 transporter) located among others in skeletal muscles. The result of such action is growth of glucose capture into muscles by activating enzyme of kinase triggered by AMP (adenosinemonophosphate) leading to generation of ATP (adenosinetriphosphate), that is energy for the cell. The difficulty is to keep a relevant concentration of glycogen because the growth of AMP kinase concentration results in boost of glycogenolysis. We need to remember that for winter endurance sports, such as Nordic skiing, a key role is played by carbohydrate supply during workout.
Anna-Maria Borucka, dietetyk Rehasport Clinic