By David Henry,
CTS Ultrarunning Coach
Keeping your feet happy is important for all runners, and between weather extremes and long training weeks, it can be particularly challenging for ultrarunners. For some reason, I developed a keen interest in keeping feet happy in long races, which has led to a lot of research and experimentation. There is no single solution that works for everyone, but you can solve a great proportion of problems by focusing on shoe fit, moisture control, and training your feet for the rigors of ultrarunning. The following are the best ways I’ve found to address these issues in training and increase the probability of a good outcome in ultramarathon races:
Shoe Fit Is King
When it comes to keeping feet happy, less sore, and blister-free, the fit of your shoes is the most important variable. In my view, three major components contribute to great fit, although they are often overlooked:
- Security=Comfort. This is especially true in longer or more technical races, and is the something most runners overlook when in the market for new shoes. In footwear, “security” refers to the amount of movement between your foot and the shoe. High security means your foot moves very little relative to the shoe. Low security means your foot moves a lot within the shoe (e.g. foot sliding forward and cramming toes into the front of the shoe on a downhill). Yes, wide toeboxes and sock-like uppers are nice and comfy, but if you select a shoe for those features at the expense of security, too much movement in the shoe causes trouble, especially the longer or more technical the race.
- Choose the Right Last shape. The last of a shoe is the shape of the mold used to create the upper. Unless you are getting custom lasted or 3-D printed shoes (i.e. pro runners), your shoe is based on a generic last that, while likely designed to fit a wide range of runners, still may not be right for you. Somewhat surprisingly, lasts come in a wide range of shapes, both within and between models/brands. Issues of toe box, midfoot and heel shape, as well as overall volumes in each of those areas, can make or break the fit of the shoe. Midfoot volume is one to watch in particular because it tends to have more impact on security than the other areas. A shoe with a baggy midfoot fit is bound to cause problems with security (see above) as soon as a runner is running on anything other than flat ground. Your foot will move around too much, which leads to more friction and less control.
- Proper lace tension without discomfort. Being able to achieve enough lace pressure to keep your foot in place but not dig into the top of your foot is critical for comfort ultramarathons. If you can’t tie the shoe tight enough, your foot is going to move around too much, but if it cuts into your tendons when you tighten it properly, that is a problem that will only get worse during longer or more technical runs. Look for good tongue/lace designs, both in padding and lace pressure distribution. Lace width and amount of stretch can be variables to consider as well.
Moisture contributes to movement, which leads to friction. It also messes with the fit of shoe uppers (they stretch or are more abrasive), and softens the skin over time. All of these are problematic if not mitigated in some way. My moisture management strategies take a couple different angles:
- Breathable uppers. Other than in very extreme cold, go with shoes that have the most breathable uppers that don’t sacrifice security or fit in the process. It is almost impossible to keep water out of shoes in wet weather or routes with water crossings, so ditch the Gore-Tex or waterproof uppers for everything but pretty cold days or shorter runs (for me that is under 25 deg F and/or 2 hours in length). Instead, wear shoes that drain well and dry out faster.
- Wear thinner (or no) socks. The less sock material you have on, the less water will be trapped either next to your feet or between your sock and shoe. While innovative sock fibers are better at transporting moisture than less ideal fibers, they still hold more water than nothing at all, so work at minimizing water retention by using less or no socks (more about less/no socks later).
- Change shoes and socks often. Changing out of wet shoes or socks as often as reasonable during long ultramarathons can be one of the best ways to mitigate moisture-related stress on the feet. An even more nuanced approach can incorporate changing into different types of shoes or socks during an ultramarathon in to vary the stresses on your feet. Of course, to pull this off you also need to consistently train in those shoes in order to condition your feet.
Train Your Feet
Not even the best equipment and moisture strategy can save you if you don’t train your feet. For most runners training the feet and increased running volume go hand in hand. The more you run, the more resilient your feet will become and will you build resistance to blisters, so run more! However, if you are running as much as you can already and still having blister problems, there a few things you might be able to do in training to increase the tolerance your feet have to the demands placed on them.
- Reduce sock protection over time. If you wear thick, extra padded socks, bump down to thinner versions for your normal everyday runs and just use the higher protection socks for your longer runs. Chances are you are not going to develop a big problem on an hour run and that extra stimulus to your feet will only contribute to stronger feet the next time you need to test your limits. Thinner socks also allow for a closer fit and less moisture retention, both of which also help reduce the issues as we’ve already discussed.
- Vary the stimuli from the upper of the shoe. While many folks rotate shoes for other reasons, foot resiliency isn’t often one of them. However, the more types of shoes you can tolerate, the more options you have to select the right shoe for varying conditions and/or length of run. During races, this experience with mutiple shoes enables you to change shoes in order to deal with unforeseen problems. Go-to shoe models are great as long as they never fail, but what if they do? Have a few good backups and train your feet to their subtle fit differences and wear points, then utilize each of their strengths to your benefit.
- Ditch the socks. This is controversial advice, but I recommend systematically reducing sock protection over time and then, when you can do long runs in thin socks without issue, try running short runs in good conditions without any socks. This adds more stimuli for your feet to adapt to and can increase security and reduce moisture retention by removing that extra layer (the sock) between your foot and the shoes. The benefits of going sockless are closer fit with less internal movement, and less material to retain moisture. Both of these are wins for the feet over time. Sockless running takes a long time to adapt to (from my personal experience, it took years to be able to do ultras without socks), but you can add it to your training with low levels of risk on very short outings and still benefit from having more resilient feet on longer runs or in nasty weather where you are still using socks. Basically, the idea is to use the appropriate levels of protection for each run (i.e. the least you need to avoid a blister) and no more. By doing so you adapt to greater forces on your feet, and won’t be required to make a binary no socks or only socks choice for every run. The benefits will apply regardless if you still want to race with socks, because your feet adapted to greater stress in training.