Footwear is one of the biggest contributors to marathon blisters, there are many reasons for this, and most of them are easy to fix.
Common blisters due to footwear are located on the side of the little toe, big toe, tops/tips of all the toes, and on the back of the heel.
Ensuring that your running shoe has enough width/ depth at the toe box and overall length as after 26 miles the foot will increase in volume by retaining fluid and can increase from 1/2 to a full-size in some cases. (most brands do width fittings now)
Try Engo patches on any areas of the footwear that are rubbing
If you are one of these people whose feet swell after running and especially if the weather is warm, then size up your marathon running shoe a half to a full-size larger. Lace locking will then keep the foot secure in the shoe and stop it from moving around too much
Training with two pairs of trainers at the same time, preferably with one that is waterproof, (on a very wet day these will keep you drier)
Take both pairs to the marathon, you might lose one pair, or the dog may eat one and yes these things really do happen. The last thing you need on the day is to be panicking over footwear. Both training pairs you will be familiar with, and your feet will already be conditioned to.
Do not use a new pair of trainers that you haven’t used before; you would be surprised how many participants do
If you are thinking of running in barefoot footwear. Make sure that you have participated and trained with barefoot running shoes for a long period of time to make sure that your feet are conditioned to this type of footwear. We have seen the result of runners trying them out on marathon day and it doesn't end well.
Cushioning soled trainers reduce the pressure on the sole, decreasing the chances of blisters in this area, Hoka has led the way for some time now in this domain, other brands have increased cushioning underfoot too.
As an alternative option, Poron insoles can increase the cushioning in your existing trainers without purchasing a new footwear. If you can fit the 6mm thickness into your shoes, then go for this option and remove the existing shoe insole to accommodate.
Preparing your footwear for the marathon day is so important and yet so under rated, use the tips above to complete your marathon without blisters.