Physiological changes and gastro-intestinal symptoms as a result of ultra-endurance running

Abstract

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)

Relationship between gastro-intestinal complaints and endotoxaemia, cytokine release and the acute-phase reaction during and after a long-distance triathlon in highly trained men

“…Increased circulating LPS levels in patients lead to various symptoms, such as fever, shivering, dizziness, nausea, various gastro-intestinal (GI) complaints such as vomiting and diarrhoea, and ultimately sepsis [8]. Such symptoms are also frequently reported by ultra-endurance athletes, in particular GI problems such as stomach cramps or stomach ache, intestinal cramps and diarrhoea [9][10][11]. The prevalence of such symptoms has been reported to be 30-50 % among marathon runners [12][13][14].…”

Blood Glucose Levels of Subelite Athletes During 6 Days of Free Living

“…[13][14][15] Physical training is known to improve insulin sensitivity, both immediately postexercise and through multiple long-term adaptations in glucose transport and metabolism. 16 However in contrast, strenuous exercise is known to increase circulating concentrations of catecholamines, such as adrenalin and noradrenaline, to near pathological levels, 17,18 resulting in hyperglycemia and hyperinsulinemia post-intense exercise. 17,19,20 This study aims to use the CGM BG profiles and dietary habits of subelite athletes to investigate if this cohort is achieving optimal BG levels during normal free living and training.…”

Nutrient intake and performance during a mountain marathon: an observational study

“…However, data on nutrient intake during real endurance races are scant (Fallon et al 1998;Kimber et al 2002;Rehrer et al 1992;Speedy et al 2001). Although these studies provide some insight into what athletes consume when racing, they concern only a small number of participants, most of them highly trained.…”