Int J Sports Med 2016; 37(02): 104-111
DOI: 10.1055/s-0035-1555929
Physiology & Biochemistry
© Georg Thieme Verlag KG Stuttgart · New York

Changes of Hematological Markers during a Multi-stage Ultra-marathon Competition in the Heat

L. M. Rama
1   Faculty of Sport Sciences and Physical Education, Coimbra University, Coimbra, Portugal
,
L. G. Minuzzi
1   Faculty of Sport Sciences and Physical Education, Coimbra University, Coimbra, Portugal
,
H. M. Carvalho
1   Faculty of Sport Sciences and Physical Education, Coimbra University, Coimbra, Portugal
4   Faculty of Physical Education, Campinas University-UNICAMP, Brasil
,
R. J. S. Costa
2   Department of Nutrition and Dietetics, Monash University, Notting Hill, Australia
,
A. M. Teixeira
1   Faculty of Sport Sciences and Physical Education, Coimbra University, Coimbra, Portugal
3   Faculdade de Ciências do desporto e Educação Física, Research Centre for Sport and Physical Activity, Coimbra, Portugal
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Publikationsverlauf



accepted after revision 24. Juni 2015

Publikationsdatum:
28. Oktober 2015 (online)

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Abstract

This study examined the changes in resting hematological variables in ultra-endurance runners throughout a multi-stage ultra-marathon competition, and compared athletes that completed all stages with those that failed to complete at least one stage within the cut-off time of competition. 19 ultra-endurance runners competing in a 230 km multi-stage ultra-marathon, conducted over 5 consecutive days in hot ambient conditions (32–40°C Tmax), volunteered to participate in the study. Each day, whole blood samples were collected prior to stage commencement and analyzed for full cell counts by Coulter counter. Linear increases were observed for leukocytes, monocytes and lymphocytes; with increases until Stage 3 and a decrease thereafter. Granulocytes showed a cubic growth exponent, indicating decrements to baseline after the significant increments until Stage 3. Hemoglobin and hematocrit showed linear decrements throughout the multi-stage ultra-marathon. No changes in erythrocytes and platelets were observed throughout the multi-stage ultra-marathon. Granulocytes, erythrocytes, hemoglobin and hematocrit changes along the multi-stage ultra-marathon differed in runners that completed all stages compared to those who failed to complete at least one stage within the cut-off time. Multi-stage ultra-marathon in the heat has a large impact on hematological responses of ultra-endurance runners associated with altered performance.