A Survey About Feet From The 2012 Amazon Jungle Marathon

Vicky Kypta is the Medical Team Manager for the Jungle Marathon, which starts October 6 in the Amazon in Brazil. Last year she did an informal survey of the participants and the results are interesting. The race lasts seven days and goes through the jungle on pre-existing paths, trails, and tracks with natural obstacles to pass including streams and shallow rivers. This leads to feet that are constantly wet.

Jungle Marathon foot care

Jungle Marathon foot care

This is the race that I will be at in a few days.

Vicky shared the results of the questionnaire and commented it was quite interesting, although the sample group was quite small. There were about 30 participants.

Here are some of the findings:

  • 77% of the respondents wore Injinji socks
  • 100% of those NOT wearing Injinji sock got blisters
  • 46% of those wearing Injinji sock got blisters: out of those 50% were on the balls of the foot and 50% were on the toes. Those who had blisters on their toes all wore shoes in their normal size.

Out of those with no blisters:

  • 100% wore Injinji socks
  • 100% wore shoes one size larger
  • 75% applied some form of anti-friction compound to their feet; i.e. Body Glide, 2nd Skin or Zinc Oxide cream
  • 75% pre-taped problem areas or hotspots

I find this interesting and wonder what we will find with the 78 participants next week. The Jungle Marathons are well run and the staff tells runners to train with wet feet. They have found this results in less foot problems.

The results are striking in several areas (remember this is a seven day stage race):

  1. All the runners who did not get blisters wore Injinji socks and shoes a full size larger than their normal shoes
  2. All the runners who did not wear Injinji socks got blisters
  3. Runners wearing their normal size shoes all got toe blisters
  4. The majority of blisters were on the forefoot and toes

Over the past 17 years, I have worked a lot of ultramarathons and multi-day stage races. I can honestly say that overall, feet have improved. More runners are prepared and know how to manage their feet.

When I return, I will share what we found at this year’s Amazon Jungle Marathon.

Moisture on Your Feet – Moist, Very Wet or Very Dry

September 22, 2013 by · 1 Comment
Filed under: blister care, Foot Care, Health, Sports, Travel 

Back in May I posted an article about Training With Wet Feet. My being invited to work on the medical team at the Jungle Marathons in Vietnam and the Amazon prompted the article. While the Vietnam race had to be cancelled, the Amazon race is happening – in a bit over two weeks.

As I wrote in that article, it was long felt the best way to manage your feet was to keep them as dry as possible. This was more and more evident as Denise Jones and I worked the Badwater Ultramarathon in the heat of Death Valley each July. Runners who kept their feet dry typically finished better than those who had wet feet. This was also based on our experiences at Western States and other events.

Then came the invite to help at the Jungle Marathons.

The Jungle Marathons are run by Race Director Shirley Thompson and the Medical Team Manager is Vicky Kypta. They found their runners had a better race when they trained with wet feet. As part of their instructions to their race participants, they stress the importance of training with wet feet.

The reason for this is the Jungle Marathons are wet. Very wet is typical in the jungle. Whether through rivers or streams, the Amazon is full of water.

When I am helping runners at the race in early October, I will be closely monitoring the condition of their feet. I expect runners will use lubricants and other products to control the moisture, or powder, socks, well-draining shoes, and maybe a few home-grown tricks.

Over the past few months, I have shared some of the findings by Rebecca Rushton, a podiatrist from Australia. In her Blister Prevention Report, she talks about managing moisture control. She supports her report with studies from medical and other professional journals. What she found through the studies is that you could reduce the incidence of blisters by keeping the skin either very dry or very wet.

Rebecca writes that, “… the very high or very low skin moisture strategies aim to reduce the coefficient of friction value between the sock and the skin to below blister-causing levels.”

The Coefficient of Friction

The coefficient of friction (COF) is the number that represents the slipperiness or stickiness between two surfaces. According to studies, this number is generally below 1.0. Inside the shoe, the COF between the foot’s skin, and the sock and insole can range from 0.5 and 0.9. Compare this to the COF between a sock and a polished floor – about 0.2.

In Rushton’s report, she illustrates this with an example of a runner whose feet sweat a lot. His socks become damp, creating a moist condition. The COF in this case might be 0.7. By moving away from a moist condition to either very dry or very wet, the runner might reduce the COF to 0.5. If the runner’s blister-causing threshold is 0.6, getting to 0.5 will reduce his chances of blistering. Reducing the COF between your skin and socks/insole combination is important to having healthy feet.

Moist Skin

Moist skin produces higher friction than very dry or very wet skin. Whether skin is dry and becomes moist through sweat or through a water moisture source, or is very wet and becomes moist through heat or simply drying out, when it hits this middle stage, it becomes more susceptible to blistering.

Very Dry Skin

Drying the skin can be done with powders, antiperspirants or other drying agents, used by themselves or in conjunction with moisture control socks. Keeping the skin very dry is tough because our feet sweat naturally. Humid or hot conditions can also make it hard to keep the skin dry. Dumping water over your head to cool yourself can result in water running down your legs into your shoes – defeating your efforts to keep your feet dry. Airing your feet with shoes and socks off can help. If you use powders, make sure it is high quality and does not cake, which can be an irritant. When counting on any of these methods to keep your skin dry, you mush also have shoes that allow moisture to escape. That may include shoes with mesh uppers and drain holes in the arches and heels.

Very Wet Skin

Increasing skin moisture leads to very wet, lubricated skin that reduces the skin’s coefficient of friction. This can be through the use of a lubricant and or by simply having wet feet. The thing to remember is that over time, 1-3 hours, friction will increase as the lubricant is absorbed into the socks – so ongoing application is required.

Amazon Wet Foot

Amazon Wet Foot

Remember too what happens to your skin when you spend too much time in the water. It becomes weaker and less able to resist trauma on wrinkly skin. In extreme cases, the skin can fold over on itself and split. Severe maceration can be painful and athletes say it feel like a giant blister on the bottom of their feet.

In the Amazon Jungle Marathon, the trick will be to dry the feet at the end of each day’s stage. Because the feet will be wet during much of each day’s stage, the runners will have to find the balance between very dry and very wet, avoiding moist as much as possible.

Here’s some advice from my previous post about training with wet feet.

As said earlier, stop and deal with any hot spots as soon as you feel them. Check for folds in your socks, friction from dirt or sand, pressure inside your shoes – and get rid of these irritants. Lube the area or apply a piece of tape or blister prevention patch to help. This may seem like common sense, but many people ignore this simple step.

At the end of each day’s stage, remove your wet shoes and socks, dry your feet and air them as much as possible. If your feet have tape on them, remove the tape to dry the skin underneath. Wear sandals or Crocs around camp to keep your feet away from the wet ground and dirt and sand. Walking around barefoot will often aggravate wet, cold, and soft macerated skin. Later in the day or the next morning, re-tape your feet and patch any blisters.

Rest assured that I will write about how everyone’s feet held up in the wet Amazon jungle.

Credit is due to Rebecca Rushton for her Blister Prevention Report. Her website is Blister Prevention. Check out her website and sign up for her newsletter and free reports.

Here is the link to the Jungle Marathon Amazon.

If you want to read more, check out this article I did in November 2012 about Stuart Crispin who completed the race in Vibram FiveFingers.

Training for Blisters in Wet Conditions

September 15, 2012 by · 2 Comments
Filed under: blister care, Foot Care, Health, Travel 

I have worked a lot of events. Every one has its one set of conditions that stresses the participants’ feet. Sometimes, it’s the dry heat of Death Valley or the rainy British Columbia coast, or the ups and downs on the trails of the many trail hundreds.

For years, the norm has been to avoid getting your feet wet. Wet feet often mean skin that is soft and can become macerated. In long events, and especially in multi-day events, that can lead to trouble. Taping or patching wet feet, or macerated feet, is very difficult. So it is best to keep your feet as dry as possible.

And then there’s the Jungle Marathon.

The Jungle Marathon is held in the Amazon Rain Forest of Brazil. This year’s race is held over October 4 to 13.The race is in the stunning State of Para – often referred to as the Caribbean of the Amazon. Competitors have the choice of two distances: 240km or 100km, which will be completed in stages throughout the week. The longer distance will include six stages and the shorter will include four. Imagine running through the jungle with stream crossings, wet foliage, wet trails, mud, and extremely humid conditions. Your feet are always wet.

At the Jungle Marathon runners have to be self-sufficient, carrying their food and provisions during the race. They are provided bottled water at designated checkpoints. Nights are spent sleeping in hammocks at campsites along the shores of the river.

Shirley Thompson is the race director and she stresses, “Our medical team has many years experience in remote locations. Your safety and well-being is our prime concern and we employ only the most experienced personnel to assist us.”

Shirley told me, “We always advise runners to train with wet feet so that they can focus on a strategy before they get to the jungle. We also tell them to buy your book and try to find a strategy that works for them. As far as footwear is concerned, we always emphasize trail shoes with good grip, and that comfort is the main factor.

I personally spend quite a bit of time in the jungle preparing the trail and doing a trial run of the course, and I always use the same strategy, which I found years ago in your book. I spray on two coats of New Skin Liquid Bandage, then wear SealSkinz hi-tops, with a thin lining sock. I have never had a blister.”

Vicky Kypta instructs new medics who join the team on foot care and she gives clinics for competitors in the United Kingdom on foot care and preparation for the race. I emailed her and asked about their strategy for managing runner’s feet. Here is her response.

River crossing

River crossing

“Feet are soaked from the start of each stage, so in the end it made more sense to get people used to their feet being always wet. We found runners had less problems during the race when they had trained with wet feet. There was a lot of hideous feet in the first couple of years of the event before we adopted this strategy.

As far as blister prevention is concerned, we encourage all runners to find a shoe/sock combination that works for them and to train in them including getting them wet. During the race, the runners are told to stop and deal with any hot spots as soon as they start which includes not waiting to get to a checkpoint. It is amazing how just stopping for 20 minutes to deal with feet saves so much time and pain later in the race.

Some runners have their own preferences on how to treat blisters and if they do then we follow their instructions otherwise we tend to drain non-blood filled blisters. On those hardy enough we the inject compound tincture of benzoin to help seal the space created by the blister, to serve as a local antiseptic, and to prevent further abrasion or loss of skin. However, due to the intense burning sensation experienced for a few moments after injection not all runners want this method used – so for all others we drain the blister and then use the benzoin over the top to provide a tacky surface to help the tape stick. Over the top of the blister we then apply a layer of fleecy web and tape over that using zinc oxide tape.

Over toes we just use tape without the fleecy web as otherwise it becomes too bulky resulting in the runner being unable to put their shoe on.

Some runners like to use Compeed on their blisters and whilst they are very good at protecting the blister we have found through experience that with an ultra event such as the Jungle Marathon, they are very difficult to remove should there be any further problems with the blister later on during the race and more damage is often caused in attempting to remove them so we therefore don’t encourage their use.

Jungle Marathon foot care

Jungle Marathon foot care

Over the years we have been very fortunate and have had very few macerated feet as at the end of each stage we get the runners to remove all the tape and to thoroughly dry out their feet. Blisters and problem feet are then freshly taped later that evening or the next morning ready for the next stage.

Despite the incredible punishment the runners feet endure during the Jungle Marathon, year after year we have very few cases of macerated or infected feet which I believe stems from early and effective treatment of problems as they arise.”

Vicky holds foot care clinics including medical care prior to the races to help provide the runners with increased knowledge to enable them to treat themselves more effectively which will hopefully reduce the amount of foot problems even further.

The Jungle Marathon helps their runners successfully complete the race because of their unique approach to foot care. Here are my observations:

  1. They encourage participants to train with wet feet
  2. They even suggest soaking your shoes and socks before heading out for a training run
  3. They give specific advice that runners find the best shoe and sock combination for their feet when wet
  4. After each day’s stage, they have runners remove their tape, which allows the skin to dry out – re-taping afterwards

This combination of advice and attention of the runners keeping their feet healthy for the multiple stages of the race works well. I commend Shirley and Vicky and the Jungle Marathon for their success with foot care.

I encourage you to check out their website and Facebook page. If you are looking for a stage race with adventure, this is a well-organized event.

Here’s the link to the Jungle Marathon’s website.

Here’s the link to the Jungle Marathon Facebook page.