Transitioning From Heavy Backpacking Boots to Trail Runners, Part I

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Why?

As with any sport or activity, hiking has it’s adages that you’ll hear over and over once you’re spending time with participants of that activity. As a hiker, two things that you’re likely to hear are “cotton kills” and “1 pound on your feet equals 5 pounds on your back.” While “cotton kills” immediately made sense to me, I didn’t necessarily buy into the “1 = 5” saying. While it made sense that it took more energy to move heavy hiking boots vs. lighter options, the “1 = 5” seemed to be exaggerated, until I started to think about momentum, inertia and the energy needed to stop and get boot weight moving. With some Googleing, I learned that “1 = 5” was researched by the British Army:

ENERGY COST OF BACKPACKING IN HEAVY BOOTS.
Legg, S. J. (Army Personnel Research Establishment, Farnborough, Engl); Mahanty, A.
Source: Ergonomics, v 29, n 3, Mar, 1986, p 433-438
ISSN: 0014-0139 CODEN: ERGOAX

Abstract: Previous studies have investigated the oxygen cost (VO//2) of increasing boot weight during unloaded walking or running, and have shown that for each 100 g increase in weight of footwear there is a 0. 7-1. 0% increase in VO//2. In reality (except in athletic events) the use of heavy footwear is associated with load carriage, usually backpacking. We therefore investigated the effects of increasing boot weight by 5% of body weight on the VO//2 of backpacking a load amounting to 35% of the body-weight in five healthy young males who walked at 4. 5 km/hour (0% grade) on a motor-driven treadmill. The results indicated a mean increase of 0. 96% in VO//2 whilst backpacking for each 100-g increase in boot weight. In contrast the oxygen cost of increasing the backpack load was only 0. 15% indicating that it was 6.4 times more expensive to carry weight on the feet as compared to the back.

source: http://www.tandfonline.com/doi/abs/10.1080/00140138608968276

 

As it turns out, the British Army found that it 1 pound on your feet actually equals 6.4 pounds in your pack in terms of energy expenditure!

After my first summer of intense training for Mt. Whitney, I was a believer, but still reluctant to use trail runners. I’ve always had weak ankles and one of the biggest limiting factors regarding how far I could comfortably hike was “bottom of forefoot pain.” At times, I have also experienced arch and metatarsophalangeal joint (MCP – the joint at the base of the toe) pain. After several years of consistent hiking, I found that my feet faired much better with heavy backpacking boots. I believe that this was due to them having a full shank, which protected my feet from feeling every root or rock I stepped on. On long hikes, I would also experience this pain with lighter hiking boots; if I used trail runners, I also noticed that I would develop the MCP pain. It seemed that the more fel I had hoped that if I used heavy boots long enough, I would just become a stronger hiker and that my legs would get used to the weight of boots. Unfortunately with the heavy boots, I noticed that I started to develop issues with my hips. It was clear that I need to try something different.

My first idea was to find a lightweight runner with a full shank and use them with ankle braces, but that search came up fruitless. My second idea was to find an insole that could stiffen the sole of a trail runner.  With a Google search for “shoe sole stiffener,” I learned about MyFootShop.com. Through the search, I ended up on a page selling their Spring Plate – Carbon/Graphite Fiber Insoles. They claimed to help with forefoot pain, as well as some other issues:

Indications: The primary benefit of the Spring Plate – Carbon/Graphite Fiber Insert is their rigidity and toe spring. Spring Plate – Carbon/Graphite Fiber Inserts act as a shank and are used to stiffen the shoe. Spring Plate – Carbon Graphite Fiber Insert are used to treat forefoot pain, forefoot capsulitis, forefoot bursitis, metatarsalgia, forefoot callus, Morton’s neuroma, Freiberg’s infraction, arch pain, metatarsal fractures, cuboid syndrome and arthritis of the forefoot and midfoot.

source: http://www.myfootshop.com/spring-plate-carbongraphite-fiber-insert

Looking at the wide variety of products they sell, I ran across their foot and ankle knowledge base and eventually learned of their MEDICALLY GUIDED SHOPPING™ tool . Using the graphical interface in the knowledge base, I was able to select where my foot problems are and got back a list of diagnoses related to that geographical region of the foot. After reading the articles in the knowledge base, I believed the spring plates were the correct product for me, but to confirm my self-diagnosis, I contacted MyFootShop.com and eventually ended up exchanging a few emails with the owner of the company, who also happens to be a board certified podiatrist and a hiker himself. Through our conversations, we determined that the spring plates were a good product for me and combining them with trail runners and ankle braces should yield the results I was looking for.


The Transition

I am reluctant to immediately jump from my backpacking boots to lightweight trail runners, especially for long backpacking trips. It seems like a better idea to make the transition in multiple steps, in the hopes of avoiding injury. To test the effectiveness of the Spring Plate – Carbon/Graphite Fiber Insoles, I have done the following so far:

  • I started by using them at the gym on a treadmill (set to a 30 degree incline, high intensity interval training (HIIT)). To avoid ‘big toe pain’ I usually have to wear a shoe with a semi-stiff sole.
  • Used them on a hike with a light load and flexible sole. Details: Bridge to Nowhere.
  • Used them hiking with a heavy load (35 lbs) and a pair of low top hikers with a semi-stiff sole. It was the first time in 8 years that I’d carried that much weight without using a backpacking boot with a full shank. My feet felt great afterwards! Details: Training Hike & Gear Testing (Prado Lane).
  • Used them on a backpacking trip(30+ miles) with low top hiking shoes, carrying ~40lbs. Details: Coyote Gulch via Redwell TH.

Here is some information on my old backpacking boots and the trail runners I plan to use with the insoles, showing the projected weight savings.

Oboz Beartooth BDry  Hi-Tec Flash Force Low Salomon X-Scream 3D Trail Running Shoes
Shoe Weight (per pair) 58 oz 30 oz 20 oz
Spring Plate Weight Not used1  2 oz 2 oz
Ankle Brace Weight Not used2 7 oz 7 oz
Total Weight 58 oz / 3.63 lbs 39 oz / 2.44 lbs 29 oz / 1.83 lbs
 Equivalent Pack Weight 3  371.2 oz / 23.2 lbs  249.6 oz / 15.6 lbs 185.6 oz / 11.7 lbs
Notes My preferred backpacking boots, featuring ankle support and full shank Low top hiking shoes that feature a nylon fork shank to add some rigidity. Vibram outsoles are a huge selling point for these shoes. I’m hoping to transition to shoes in the 15-20 oz per pair eventually for hiking and backpacking.

 

1 Spring Plates not needed; full shank provides adequate protection.
 Ankle braces not needed; boot height provides adequate ankle support.
3 Using the British Army’s 6.4 multiplication factor

My Observations

 

  • The Good
    • In all tests, my foot pain was greatly reduced from what I would expect when using trail runners and similar to what I feel when using heavy backpacking boots. In all tests except the backpacking trip, I had no significant foot pain. On the backpacking trip, my feet did hurt some, but with the mileage covered and weight carried, I would expect that level of discomfort even when using my backpacking boots.
    • For my treadmill test,  I put the insoles in my Salomon X-Scream 3D Trail Running Shoes, which offer minimal protection and support. If I wear these shoes for one HIIT session, I will have MCP pain the next day. After a half dozen sessions with the insoles, I didn’t experienced any pain.
    • I have not experienced any arch pain since I started using the insoles. Either the insoles or shoes I’ve been using are a better match for my arches, or the problem has gone away.
    • During the testing, I did not experience any significant ankle injures. This may be due to luck, being more conscious of foot placement, the ankle braces doing their job, or a combination of the three. Time should tell.
    • No hip pain on my long day of our backpacking trip (14+ miles). I would usually expect some hip discomfort when hiking that far.
  • The Bad
    • The insoles are expensive, close to the cost of some custom orthotics.
    • I primarily shop online and with my narrow feet, it took some time to find shoes that would work well with both the insoles and my feet. If the shoes are too narrow, the edges of the insoles can cut into the shoes. If you decide to try these insoles, I highly recommend going to a shoe store with the insoles to figure out which shoe/shoe sizes will work for you.
  • The Bottom Line 
    • Expensive, but if you have existing foot pain that limits your hiking or walking (similar to what I’ve had), I recommend trying them. For day hikes, I am confident that I can hike with lightweight trail runners, the insoles and ankle braces. After more testing, I believe I will transition to lightweight trail runners for backpacking trips also, but I will not know without more time & testing.

Future Testing

My friends, who are well aware of my previous foot and ankle issues, were very surprised that I used low top hiking shoes on the Coyote Gulch trip. After testing some different combinations of gear, I am hoping that I’ll be able to determine if the insoles in any trail runner (read: further weight savings), the shoes by themselves (read: $$$ savings) or the combination of the two will give me the level of protection and support I need. I am also curious about the durability of the insoles themselves and wondering how many miles I can get out of them.



Disclaimer: Some of the products mentioned in this entry were provided to HikingGeek.com by MyFootShop & Hi-Tec.