The purpose of the project is to investigate urine concentration after inhalation of salmeterol. This will be examined following acute physical activity under both normal conditions and heated conditions.

Inclusion Criteria:

• Inclusion Criteria:
• Age 18-40
• Physically active >5 hours a week
• Maximum oxygen uptake classified as high or very high

Exclusion Criteria:

• Active smoker currently or within the past 5 years
• Regular intake of medication deemed by the responsible study physician to affect the test parameters (hormonal contraception is accepted for women)
• Chronic or acute illness deemed by the responsible study physician to affect the test parameters
• Deviation from the study protocol
• Lean mass index >21 kg/m²
• Pregnancy
• Smoker
• Blood donation during the past 3 months