How to Prevent Chafing, Blisters, & Black Toenails

Chafing, blisters, and black toenails are often hazards of running, but with some precautions, as well as some remedies, you can overcome them.

Competitive runner and running coach Joe Muldowney shares his experiences of these common running problems and gives us some tips on avoiding them.

Common Running Injuries – Chafing, Blisters, & Black Toenails

My oldest daughter, Kelly, is a veteran of six marathons, many half marathons, and countless road races. But it hasn’t always been that way.

You see, she was traumatized as a child. The sight of her father’s gnarly feet which were decorated with callouses, blisters, and black toenails, were enough to cause her to vow never to become a runner.

Fortunately, in her late 20s, she began to understand that these unpleasant side-effects of running were the result of tight-fitting shoes and numerous races run in hot weather, so she had a change of heart.

All runners will eventually earn dubious (and painful) “badges of honor”. These badges will slow you down, impede your race performances, and cause you discomfort, discouraging you from training. Prevention is the key.


1) Get the Correct Running Shoes

Chafing, Blisters & Black Toenails | Linked Fitness CommunityStart with your shoes, the most important equipment purchase for every runner. Always try on your shoes before you buy them.

Most runner stores will allow you to “test drive,” or take a pair of shoes for a short run before purchasing.

Never buy a pair of running shoes that are too tight. If you do, after a couple of workouts, a toenail or two may turn pink, then black.

A general rule is to allow around a thumbnail’s worth of room between the top of your big toe and the front of your shoe.

Conversely, if a shoe is too big, the flopping of your foot inside the shoe will cause blisters.

2) Use Petroleum Jelly

During hot weather, chafing in those sensitive areas can often cause discomfort. Arm pits, and the crotch are the most vulnerable areas for chafing.

There are several products out there that address the issue of chafing, and I won’t endorse any over the other. But a simple, cheap, and rather “Old School” method of avoiding chafing is applying a layer of petroleum jelly to areas in which friction occurs during the run.

The same is true for blisters on your feet. Before putting on your socks, apply a thick layer of petroleum jelly to your toes, heels, or the sides of your feet where blisters may develop. It may feel uncomfortable at first, but as you begin to run, you won’t even feel it.

3) Invest in Compression Wear for Chafing

Chafing, Blisters & Black Toenails | Linked Fitness CommunityPerhaps the ultimate chafing pain occurs in men, in the form of chafed nipples.

No one wants to be the runner who comes across the finish line with streams of blood running down the front of his singlet.

The simple solution here is to always wear a compression-type shirt that reduces the friction. A regular singlet will bounce as you run, creating the irritation.

Also, old-fashioned adhesive strips (band-aids) work well. Use two of them in an “x” pattern, to maximize protection.


Sometimes, despite every precaution, you may still suffer from one of these afflictions following a training run or race.

The remedy for chafed areas is simple. You should use a skin cream of your choice to reduce the irritation.

For troublesome blisters, I would recommend popping them with a sterile needle. This will drain the fluid. If you are going to try this treatment, however, it is essential to keep the area clean to avoid infection.

If a black toenails occur and they aren’t painful, no action is usually necessary. Eventually, you will lose the toenails and brand new ones will appear.

If a toenail is painful and is causing you problems, the remedy is often not pretty. You should consult your doctor who will discuss treatment options with you. These may involve toenail removal or drainage of the blood under the nail using a needle.

About Joe Muldowney

Chafing, Blisters & Black Toe Nails - Joe Muldowney - Linked Fitness Community Author Joe Muldowney is an accomplished runner who has been involved in competitive long distance running for 40 years. His vast experience has enabled him to coach several running teams and he now provides a one-on-one coaching service.

During his running career he has run 54 marathons, 51 of which have been under 3 hours. His best marathon time is 2:22:54, and, at age 57, he ran the 2010 Philadelphia Marathon in a time of 2:58:56. The Boston Marathon is a particular favourite – he has completed this an impressive 16 times. Marathons aside, he has run more than 1000 road races, and logged over 123,000 miles.

Joe is also the author of the book “Running Shorts: A Collection of Stories and Advice for Anyone Who Has Ever Laced Up a Pair of Running Shoes” and his latest book is, “Personal Best.”

 To find out more about Joe Muldwoney, you can visit his blog

View Joe Muldowney's Profile

Recommend0 recommendationsPublished in Injury, Running, Training


  1. Pingback: Marathon Training: A Guide for Beginners | Linked Fitness

Your email address will not be published. Required fields are marked *