Only very few studies have prospectively looked at the effect of repeated intensive plasma donation. In collaboration with the Rode Kruis Vlaanderen, we have recently found that repeated whole blood donation with a 3-month interval in between induced a drop in markers for iron status, which worsened with the number of donations. The repetition effect of the donations, whether whole blood or plasma, can be different from the effects measured after one single donation. It is therefore critical to test and document this repetitive effect to build trustable and valid guidelines concerning repetitive plasma donation.

Inclusion criteria:

• male,
• age between 18-50 years
• BMI between 20-28 kg/m2
• aptitude to perform maximal physical efforts assessed by the physical activity readiness questionnaire (PAR-Q)

Exclusion criteria:

• The specific exclusion criteria of the Rode Kruis Vlaanderen for blood donation will not be systematically applied to the present study to increase the pool of recruitment.

  • In case the subjects do not comply with the criteria of the Rode Kruis Vlaanderen, their plasma donations will be thrown away.
  • In case the subjects comply, their plasma donations will be handled as usually.

• The criteria will be assessed before each plasma donation by a questionnaire as usually done in the Center of the Rode Kruis.