Linking current research to running
By Nikki Reiter
In this first post of a four-part series on ultra-running, I’ll address some of the physical deterioration associated with ultra-running. While physical activity by way of running is a very healthy endeavor, with extreme exertion comes health risks. A growing number of researchers are investigating whether these risks outweigh the benefits.
A recent article investigated whether damage to liver and skeletal muscle occurs during a 100km run – and whether this potential damage is related to age (is there more damage as one ages?) or running speed (is there more damage the faster one runs?). They also sought out to determine the optimal running speed and distance based on a runner’s current health status.
Here’s how it went: Fourteen experienced male amateur ultra-marathon runners took part in a 100km run. Blood samples were taken at 0, 25, 50, 75, 100km and 24-hours after the run to detect changes in liver and skeletal muscle enzymes.
The result: Increases in both liver and skeletal muscle associated enzymes were observed with each sequential course (especially after 50km) as well as into recovery (at 24 hours after completion of the run). Older runners demonstrated higher activity of liver enzymes during the run over 50km and during recovery. Faster runners demonstrated better adaptive abilities to the exertion by exhibiting lower activity of liver and skeletal muscle enzymes.
What this means: It appears that advanced age and slower speeds (a factor of a lesser training status?) may result in increased liver enzymes and lead to muscle damage.
A final comment: Since the highest level of potentially toxic levels of liver enzymes during the run were apparent at 50km, there is a distinction between the classic marathon distance of 42.2km and ultra-marathon distances when it comes to damage the body. Frequency of ultra-marathons should be kept to a minimum. Blood samples could be evaluated before return to training after an ultra-marathon.
Nikki Reiter is a Biomechanist and certified NCCP Performance Coach in Endurance Running. She offers online gait analysis through Run Right Gait Analysis. Visit her website www.run-right.ca for more information.