Most runners should not get blisters. There are some events where it's hard to avoid getting blisters such as downhill races or ultras however in runs of 80k or less it shouldn't happen. Blisters are primarily caused by shearing force, where force is applied to the skin across its surface. Blisters can also be formed due to poor fitting shoes, poor form, the wrong socks or lose of electrolytes from sweating.
In the past we have discussed having a properly fitted shoe, making sure that you have enough room in the toe box for swelling of the feet but one that is not so big that you move around inside. Most recently we discussed proper socks, ensuring we stay away from cotton socks that deform and absorb moisture. What might be news to you is that your form or lack of hydration and/or electrolyte ingestion may be causing your pesky, painful blistering.
If you think that blisters are only for those who wear shoes, one of the topics of discussion on barefootrunners.org is blistering. It is well known that blistering is caused by shearing forces, grinding of the foot or pushing rather than lifting. Bad running form will not only make you slow and cause injury, but it is also one of the leading causes of blisters. With a good cadence and running form, your feet will land gently and quietly on the ground, producing little shearing force or impact regardless of what's on your feet. A slow Cadence or a poor running form will produce a sharp shearing force that will tear at the skin, causing blisters over time. Running downhill can make the shearing forces far worse, and a poor downhill running style is likely to cause serious blisters. When running downhill, your foot should land softly and the braking force should be even for the time the foot is in contact.
According to the Kevin Sayers of
www.ultrunr.com swollen feet, blisters, and black toenails are indicative of dehydration due to lack of electrolytes, not lack of water intake. It maybe that for many of us, we have now been trained to drink enough water, but not to monitor our electrolyte level and take enough salts. If salt levels are low, it doesn't matter how much we drink, we are still dehydrated. When sodium levels in the blood fall below a certain level, water from the blood plasma will be transferred into tissues external to the circulatory system, causing your feet to swell. Those swollen tissues are less able to support the mechanical abuse of running and walking on them.
So to prevent blistering a good fitting shoe with proper socks is a good start then have someone assess your running stride to make sure you are driving with your knee not pushing off with your foot and most importantly stay hydrated and replace lost electrolytes.
This weekend join Tri & Run Sports in Batawa for the Frozen Ass Snowshoe race 4k/8k on Sunday at 10am. If there is not enough snow it will be a trail race.
