Ultra-Long-Distance Running and the Liver*

Abstract

During an ultra-long-distance race (1000 km in 20 days) the influence of running was examined on the enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), gamma-glutamyl-transferase (GGT), and glutamate dehydrogenase (GLDH) with regard to their release from the liver cells or their induction. Furthermore the liver synthetic capacity was assayed by measuring the enzyme activity of cholinesterase and the concentration of serum albumin during the race. Of the 110 participants, 55 finished the race and only the results of these runners were used in our study. AP increased continuously from day 0 (mean = 102 U/L) to day 19 (mean = 120 U/L). A fivefold increase of AST and a twentyfold increase of CK up to day 3 was followed by a significant decrease towards the end of the race. ALT rose as well up to day 6 from a mean value of 8 U/L to 24 U/L but remained at this level. Surprising was the individual increase of the enzymes GLDH (up to twentyfold) and GGT (up to sixfold) in more than half of the finishers on various days indicating liver cell injuries. The activity of CHE and the concentration of serum albumin decreased during the race, both were significantly correlated.

Elevations in serum muscle enzyme activities in racehorses due to unaccustomed exercise and training

“…GGT activity of between 70 and 100 U/l have previously been associated with poor health and overtraining in the horse, and further, those horses with high GGT values showed a markedly reduced incidence of increased GGT following reduction in training intensity in subsequent years (Snow and Harris 1988). It is also possible that cumulative training load causes some degree of liver cell injury as has been found in ultra-long-distance running in human athletes (Nagel and others 1990). …”

Efeitos agudos do exercício físico prolongado: avaliação após ultramaratona de 24 horas

“…It is known that CPK levels increase after great physiological stress [10][11][12][13][14][15][16][17] , indicating intense catabolic state of skeletal muscle. The intensity and duration of physical exercise are commonly associated with CPK increase and there seems to be a predominant effect of duration 16 .…”

The biochemistry of runners in a 1600 km ultramarathon.

“…However, whereas lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) are found in both liver and muscle cells and therefore increases in these enzymes cannot specifically indicate liver cell damage, Nagel et al 9 have suggested that a decrease in CK and AST after the third day of running that is not accompanied by a decrease in ALT may indicate reduction of skeletal muscle damage with continuing hepatic cell injury. The third hypothesis was therefore that changes in these enzymes would be similar in this event to those in the study of Nagel et al and that this would support a further study in which liver-specific enzymes would be measured.…”