Physiological changes and gastro-intestinal symptoms as a result of ultra-endurance running.
One hundred and seventy-two competitors of the Swiss Alpine Marathon, Davos, Switzerland, 1988, volunteered for this research project. Of these volunteers 170 (158 men, 12 women) finished the race (99%). The race length was 67 km with an altitude difference of 1,900 m between the highest and lowest points. Mean age was 39 (SEM 0.8) years. Average finishing times were 8 h 18 min (men) and 8 h 56 min (women). Loss of body mass averaged 3.4% body mass [mean 3.3 (SEM 0.2)%; 4.0 (SEM 0.4)%; men and women, respectively]. Blood samples from a subgroup of 89 subjects (6 women and 83 men) were taken prior to and immediately after completion of the race. Changes in haemoglobin (9.3 mmol.l-1 pre-race, 9.7 mmol.l-1 post-race) and packed cell volume (0.44 pre, 0.48 post-race) were in line with the moderate level of dehydration displayed by changes in body mass. Mean plasma volume decreased by 8.3%. No significant changes in plasma osmolality, sodium, or chloride were observed but plasma potassium did increase by 5% (4.2 mmol.l-1 pre-race, 4.4 mmol.l-1 post-race). Mean fluid consumption was 3290 (SEM 103) ml. Forty-three percent of all subjects, and 33% of those who gave blood samples, complained of gastro-intestinal (GI) distress during the race. No direct relationship was found between the quantity or quality of beverage consumed and the prevalence of GI symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)
Rehrer
N J
NJ
Department of Human Biology, University of Limburg, Maastricht, The Netherlands.
Brouns
F
F
Beckers
E J
EJ
Frey
W O
WO
Villiger
B
B
Riddoch
C J
CJ
Menheere
P P
PP
Saris
W H
WH
D000328:Adult; D000368:Aged; D001810:Blood Volume / Q000502:physiology; D015992:Body Mass Index; D003681:Dehydration / Q000503:physiopathology; D004068:Digestive System Physiological Phenomena; D004326:Drinking / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D005260:Female; D005755:Gastrins / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D009994:Osmolar Concentration; D010807:Physical Endurance / Q000502:physiology*; D011188:Potassium / Q000097:blood; D012420:Running; D014660:Vasoactive Intestinal Peptide / Q000097:blood
D005755:Gastrins; D006454:Hemoglobins; D014660:Vasoactive Intestinal Peptide; D011188:Potassium; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine