Acknowledgements:
For technical support, we want to thank Paul van Hoof, Roelof-Jan van der Lei, Geert Weijers, Andreas Boehmler and Markus Kaymer from the Beckman Coulter team. We also want to thank the whole team of the Nijmegen Exercise Study for their help with blood drawing and collection of the questionnaire data. We want to thank Tjarda Tromp, for coordinating the blood drawing procedures.