Participants

Twelve healthy college students (8 men, 4 women), aged 20 to 25 years ( Table 1 ), who regularly trained in running, soccer, and handball for a minimum of three times a week volunteered to participate in the study. Subjects who met one or more of the following exclusion criteria were not eligible to participate in the study: injuries that prevented subjects from running at high intensity during the exercise sessions, known diseases associated with systemic and pulmonary circulation, reluctance to refrain from nicotine or alcohol consumption, and involvement in another study. The subjects’ anthropometrical and physiological characteristics are shown in Table 1 . The study was approved by the Norwegian Social Science Data Services and carried out in accordance with the current ethical standards in sports and exercise research and of the journal ¹⁶ . All subjects were fully acquainted with the nature of the study and informed of the experimental risks before signing a written consent form to participate. It was explicitly stated to the subjects that they could withdraw from the study at any point. The study was conducted in accordance with the Declaration of Helsinki.

Table 1 Anthropometrical and physiological characteristics of the 12 study subjects.

Note. Values are means±SD. BMI, body mass index; VO _2max, maximal oxygen uptake.