Another subject I have thought long to write about is the most common problem all mountain ultramarathon runners are facing when racing – blisters. If you wonder why it is so common just look at this picture from somewhere in the Italian Alps during Petite Trotte à Léon (PTL) earlier this year – while a talus field is really beautiful for the eyes it is the darkest nightmare for your feet, at least when descending.
|Talus fields - the worst nightmare for your feet at least when descending|
Most of the blisters formed on the toes (65%), followed by blisters at the ball of the foot (16%), heel (14%) and sole (5%). Blisters were more painful towards the end of the race, and those of the sole and heel tended to be the most painful (although not statistically significant). Most interesting, the prophylactic measures studied (type and fabric of socks; application of antiperspirants, talcum powder, or lubricant to feet; and prophylactic taping) did not show any reduction in blister rates. The only predictive marker for reduced blister incidence was previous ultramarathon experience in men (r = -0.44, P < 0.05). I think these findings agree well with my experiences from Tor des Geants (TDG) and Petite Trotte à Léon (PTL) were my feet withstood the stress for approximately 80 hours before severe blister formation in TDG last year and around 100 hours before blister formation in PTL this year. The study also reinforces my belief that you have to find a solution to prevent blisters that works for you personally and that this solution might be different for each runner and even for each race depending on the conditions.
Looking at what others have written about blisters there exists barely an ultrarunning running blog without something about it. A really good post is by Andy Cole in his blog “Running Late” from last year entitled “Bad News and Blisters” and I can definitively recommend it. If you really want to dig into the subject “Fixing your feet. Injury prevention and treatments for athletes ”, now in its 5th edition, by John Vonhof is the reference book. It is very much written with endurance runners in mind.
In the scientific literature a lot has been written about friction blisters and sock fiber composition for instance, but no good prospective randomized controlled trials have been conducted to my knowledge of different types of socks, or any other intervention for that matter, in ultramarathon runners. Other studies also confirm the findings by Scheer and colleagues that blister formation is very common as they appear to represent 17-40% of injuries at continuous ultramarathons and 33-74% of injuries during multistage ultramarathons (for review see Hoffman et al “Medical services at ultra-endurance foot races in remote environments: Medical issues and consensus guidelines” Sports Med 2014; 44: 1055-1069).