Document Detail

Glycerol administration before endurance exercise: metabolism, urinary glycerol excretion and effects on doping-relevant blood parameters.
MedLine Citation:
PMID:  23359436     Owner:  NLM     Status:  Publisher    
Glycerol is prohibited as a masking agent by the World Anti-Doping Agency and a urinary threshold has recently been recommended. However, little is known about urinary glycerol excretion after exercise, when (1) exogenous glycerol is metabolized increasingly and (2) endogenous glycerol levels are elevated. The purpose of the placebo-controlled cross-over study was to determine the effects of pre-exercise glycerol administration on glycerol metabolism, urinary excretion, and selected blood parameters. After administration of glycerol (G; 1.0 g/kg body weight (BW) + 25 ml fluid/kg BW) or placebo (P; 25 ml fluid/kg), 14 cyclists exercised 90 min at 60% VO(2max) . Samples were taken at 0 h (before administration), 2.5 h (before exercise), 4 h (after exercise) and 6.5 h and additional urine samples were collected until 24 h. Exercise increased endogenous plasma glycerol (0.51 ± 0.21 mmol/l) but peak concentrations were much higher in G (2.5 h: 15.6 ± 7.8 mmol/l). Urinary glycerol increased rapidly (58,428 ± 71,084 µg/ml after 2.5 h) and was significantly higher than in P until 13.6 ± 0.9 h (p < 0.01). In comparison with placebo administration, G caused significantly greater changes in plasma volume and haemoglobin concentrations after 2.5 h. BW and urine production were significantly different between P and G after 2.5 h and post-exercise. Despite exercise-induced increases in endogenous glycerol in the control group, urinary excretion remained well below the previously recommended threshold. In addition, exercise-related glycerol degradation did not appear to negatively affect the detection of exogenously administered glycerol. Copyright © 2013 John Wiley & Sons, Ltd.
Karsten Koehler; Hans Braun; Markus de Marees; Hans Geyer; Mario Thevis; Joachim Mester; Wilhelm Schaenzer
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Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-28
Journal Detail:
Title:  Drug testing and analysis     Volume:  -     ISSN:  1942-7611     ISO Abbreviation:  Drug Test Anal     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2013-1-29     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101483449     Medline TA:  Drug Test Anal     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2013 John Wiley & Sons, Ltd.
Institute of Biochemistry, German Sport University, Cologne, Germany; German Research Centre of Elite Sports, German Sport University, Cologne, Germany.
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