Saturday, June 30, 2012

C5W3D6 - "Barefoot" 10k

This morning I did my first "barefoot" 10k run in 56:34. I got started two hours earlier than last Saturday and it was 76f with 72% humidity. In June I ran 35.65 miles with an overall average pace of 8:49. My fastest month since April of 2011 when I was running with Ranson and my shortest distance since last July. Part of my new years resolution was to run 1000 miles this year in memory of my Uncle Jack. 375 miles down and 625 to go. My injury in February set me back but I start marathon training in 5 weeks so my weekly volume will go back up.

Friday, June 29, 2012

16 Weeks under 172

16 Weeks under 172

Back in February I broke my nearly 2 year long plateau of 172 pounds. It was just 3 days before I injured my knee during a long training run that ended my Marathon training right at the halfway point. 6 week later I dipped below it again and have managed to stay under 172 due to giving up bread and embracing a Primal/Paleo diet. 

Since September 2009 I have used a "Ceiling Weight", a weight I won't let myself get above and take action if I reach it. Last August I decided that 190 was not serving me well and a 15+ pound weight fluctuation was too much work so I changed my ceiling weight to 180 pounds right at the start of training for my first Half Marathon. It changed the way I treat myself nutritionally and other than a bad weekend in December I have managed to stay below 180.

After eating bread at Easter after giving it up for 40ish days for lent I decided 170 would be my new ceiling weight. I developed this idea after reading the book Racing Weight and calculating my idea running weight is 160ish and it said to not let yourself gain more than 8% in the off-season. 

I want to continue to improve my fitness and leaness instead of just undoing a few weeks to months of poor nutrition. Right now I am just above 12% body fat and my long term goal I set in October 2009 is below 10%. I start training for the Dallas "White Rock" Marathon in 5 weeks and plan to be in my ideal racing weight to improve performance and reduce the risk of injury. 

16 weeks of success down and 23 weeks until the Marathon.


Thursday, June 28, 2012

C5W3D4 - HIIT/5K

This morning I could not decided if I wanted to run a 5k or do a 20 min BFL style HIIT workout. I ran out of steam after 3 miles on my "long" run on Saturday. I had been running less than 3 miles a run for 3 weeks. I decided to run for 2 minutes before I decide which workout to do.

 I started out my run around a 9 minute pace and decided to do intervals. I felt heavy as I ran but had extra energy. I was able to get under an 8 min pace during minute 6 while running uphill. After my second 4 minute set of intervals I was at Shady Oaks drive and decided to keep moving forward instead of turning around committing myself to a 5k loop. It felt cooler running on the dark empty road. I ran my 3rd set of intervals a little faster. During the last set I was determined to maintain under a 6:45 pace (my goal pace for the Rahr 5k) for the 1 minute high point. I got up to 6:33 then I did my 1 minute cool down finishing my 20 min HIIT workout in 2.44mi. My previous best was 2.26mi two weeks ago.

 Seeing a new outdoor 5k time in reach I pushed hard as I got on the grass along Loop 288. I maintained a 7:45 pace until 2.95mi when I noticed I was slowing down. I gave all I had left finishing at a 7-7:30 pace hitting 5k in 25:20 just 17 second slower than my best outdoor 5k. Part of my New Years Resolution was to run a 5k under 25 minutes. I have done it on the treadmill but not outdoor yet.

Next Thursday I WILL beat my 5k time while setting a new HIIT distance as long as July 4th does not get in the way. Maybe I should switch my 2 mile Tuesday with my HIIT Thursday workouts.

Thursday, June 21, 2012


Winston and Ellen joined me at the start of my run this morning. I get so much energy from having Ellen join me when I exercise. I did 2.25mi outdoors in a 20 minute BFL style HIIT session. I jogged an extra 0.1mi with Ellen & Winston after my 20 minutes was up.

I have lost 3.2 pounds of fat in the past two weeks. I am 4.8 lbs from my goal I set nearly 3 years ago.

2 years Workout Calendar

On June 21st 2010 I start tracking my workouts in a calendar I made. If I missed a planned workout I put a nice big now my calendar is 2 years old and I find it neat that the halfway point was our wedding.

Last night I asked Ellen, "Do you think I missed more workouts before or after our wedding?" She said before. Sure enough....

Since the week after our honeymoon I have missed 9 planned workouts (I don't count the X's from the week after our Honeymoon.) 
I have attached two calendars June 2010 to June 2011, and June 2011 to June 2012. Checkout the number of X the year before the wedding....

Wednesday, June 20, 2012

Motivation Level 10!

I am back up to a motivation level 10 right now. Lifting heavy and 100% BFL style, running short distances fast, nutrition is 100% and 60-80% on weekend. I have decided to cutt out alcohol after our 1st Wedding Anniversary and trip to Colorado. I plan cut it out the first 6-8 weeks of my Marathon training start August 1st.

Running last night has motivated me to set and new goal. Something to push me for the next 14 weeks. My very first 5k was the Rahr 5k in September 2010. I ran it again in September 2011 and have not run a 5k race since then.

"I want to place in my age division at the upcoming Rahr Oktoberfest 5k in late September. A 21min 5k should get in the top 3 or 5 in the male 25-29 based on the results from 2010 and 2011. Right now my fastest treadmill 5k is 23:48 and my outdoor is 25:02 (but that was 5 months ago). I think I would have to run 6:45 per mile and right now my fastest  one miler is 7:11 (two months ago) and 6:56 on the treadmill last month." 

My friend TC is an Army recruiter and just moved back to Texas after living in Iowa for 5 years. He has been a good supporter of my running on facebook and is the one who introduced me to Tough Mudder.

I texted him my new 5k goal today and he said, "I'll have to train up to that pace but I am down to run it with you." I told him where I am now and he said, "I think a 21 is my best when I ran all the time. We have plenty of time." 14 weeks to train...

The icing on the cake is he lives right by my old running buddy Ranson who helped me get faster AND my friend Eric who trained with me in March/April when I was nursing an IT-Band issue.

There is a nice park located close to all their houses. I would LOVE to get the group together for a run!


This morning it was hard to get out of bed. I said to Ellen, "Think beyond the present moment." We both got up, got dressed, and got to the gym at 5:30am. My workout lasted 43 minutes and Ellen did as much as she could without using her left wrist.

Tuesday, June 19, 2012

C5W2D2 - 2mi PR

After work I went stopped by the Sun & Ski Sports at Grapevine Mills Mall to exchange my VFF Bikila LS for a smaller size. I did a test sprint up on Saturday and decided they were too big on my right foot. My left foot is bigger than my right. I found the box from my first pair and saw they were a 42 and my new ones were a 43. I got home and decided I want to do a real test run. I slide on my shoes, slapped on my garmin watch, and headed outside. It was 87 degrees, humid, with a 20-25 mph wind. I decided to do my usual 2 mile out and back. I pushed myself a little and finished mile 1 in 7:25 without feeling like I was dying. I decided to keep pushing and try to set a new PR. By 1.5mi in the heat was getting to me but I kept going. I sped up a little the last 0.2mi finishing in 14:55 beating my old PR by 2 seconds. 
The Speed and Bikila LS have the same tread.

A little tighter around the toe box than the Speeds

We both have 2 pair now. From Left to Right; Men's Speed and Bikila LS, Women's SeeYa and Spyridon LS

I want to place in my age division at the Rahr Oktoberfest 5k in late September. A 21min 5k should get in the top 3 or 5 in the male 25-29 based on the results from 2010 and 2011. Right now my fastest treadmill 5k is 23:48 and my outdoor is 25:02 (but that was 5 months ago). I think I would have to run 6:45 per mile and right now my fastest mile is 7:11 (two months ago) and 6:56 on the treadmill last month. 

Monday, June 18, 2012


Due to rain I did not get my yard work completely finished this weekend so I am taking today off to finishing mowing and trimming branches before the Code Enforcement follow up inspection. No excuse to miss a workout...


Sunday, June 17, 2012


Saturday morning I overslept and missed my my window to get in my run. We went to a Texas Rangers game Friday night and did not get home until late. I woke up at 8:45am and had to swing by the Farmers Market by 9am so we could get to Dallas by 10am to pickup 2 new chickens. I slept in today too and miss out on a nice cool morning. Ellen cooked a wonderfull breakfast and we got started in the yard. We put some temporary netting on our new chicken run so the new pullets could have some extra space. Around 2:30 pm I could see a storm coming from the west. We switched to doing yard work before the rain came. It cooled off about 10 degrees so I decided to get in a run before the rain. I headed to the LA Fitness parking lot to start my usual 2 mile route. Less than half a mile into it it start sprinkling and by 1 mile it was raining. I ran thru it feeling and alive and refreshed by the rain drops. I was very thankful to get the oppurtunity to run without all the heat. I finished in 15:56 and felt good even though I had planned to do a 5 mile run over the weekend.

Saturday, June 16, 2012

Bikila LS

Today I bought a pair of Blue/Grey Vibram fivefingers Bikila LS from Sun & Ski Sport in Dallas with a $40 credit I got for $18. I could not remember what size my first pair were and the label under the tongue had worn off. I tried on 42 and 43 and did the 15 ft walk and turn test. I picked the 43s. Ellen got the bug and ended up buying some Orange VFF Spyridon LS. They are more a trail running shoe and perfect for our yearly trip to Colorado. 

 Finally got this in the mail after sending in my challenge packet over 12 months ago.
For the first time ever my calves measure 16" (down an inch) and I am starting to see definintion.

Friday, June 15, 2012


Today is my day off and I have alot planned to do. I decided to get my workout done before I start working in the yard and running errands.
Shaved my legs to remove sticker burrs from weedeating the lawn/

Thursday, June 14, 2012


I took Winston with me for my 20 minute BFL style HIIT run. We did 2.26 miles. I found the fastest he can handle is an 8min/mi pace. Last week I only ran once and I had not run outside in 11 days. Ellen worked out on the elliptical and has exercised 3 days this week. I am proud of her developing a good routine even though she "Would give anything to go back to bed" this morning.
I hopped on the scale and I am back under 170 with a 1.6 pound fat loss for the week. This is my biggest loss since week 1 of our Primal Challenge 8 weeks ago.

Update: 7am I plugged in my HIIT run into my spreadsheet and this is my longest outdoor BFL stle HIIT I have done. I put all of my 20 min HIIT workoust since I started logging my runs in September 2010 into a separate worksheet and I made this chart. (Blue is treadmill and Green is outdoors).

Then I decided that the chart is slightly misleading due to the large gaps between workouts so I made this chart using the same data. I trained for a 10k Nov 10 till Jan 11. I took off  a month in Jun/July 11. Then from Aug 11 to Feb 12 I was doing half/full marathon training. I plan to do a BFL HIIT workout once a week until the end of July.

Wednesday, June 13, 2012

Biomechanics of Foot Strikes & Applications to Running Barefoot or in Minimal Footwear

This website has been developed to provide an evidence-based resource for those interested in the biomechanics of different foot strikes in endurance running and the applications to human endurance running prior to the modern running shoe.

Harvard Skeletal Biology Lab

Daniel E. Lieberman
Madhusudhan Venkadesan
Adam I. Daoud
William A. Werbel

Collaborator Bios

In Daniel Lieberman's Skeletal Biology Lab, we have been investigating the biomechanics of endurance running, comparing habitually barefoot runners with runners who normally run in modern running shoes with built-up heels, stiff soles and arch support.

Here is a summary of our findings, which we explain with the aid of videos and images in the following pages:

Our research asked how and why humans can and did run comfortably without modern running shoes. We tested and confirmed what many people knew already: that most experienced, habitually barefoot runners tend to avoid landing on the heel and instead land with a forefoot or midfoot strike. The bulk of our published research explores the collisional mechanics of different kinds of foot strikes. We show that most forefoot and some midfoot strikes (shod or barefoot) do not generate the sudden, large impact transients that occur when you heel strike (shod or barefoot). Consequently, runners who forefoot or midfoot strike do not need shoes with elevated cushioned heels to cope with these sudden, high transient forces that occur when you land on the ground. Therefore, barefoot and minimally shod people can run easily on the hardest surfaces in the world without discomfort from landing. If impact transient forces contribute to some forms of injury, then this style of running (shod or barefoot) might have some benefits, but that hypothesis remains to be tested.

Lieberman DE, Venkadesan M, Werbel WA, Daoud AI, D'Andrea S, Davis IS, Mang'eni RO, Pitsiladis Y. (2010) Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature 463: 531-5.

Bramble DM and Lieberman, DE (2004) Endurance running and the Evolution of Homo. Nature. 432: 345-352.

Please note that we present no data on how people should run, whether shoes cause some injuries, or whether barefoot running causes other kinds of injuries. We believe there is a strong need for controlled, prospective studies on these issues.

This website provides information on:

  1. Human evolution and endurance running
  2. Foot and lower limb biomechanics when running in shoes
  3. Foot and lower limb biomechanics when running barefoot or in minimal shoes
  4. Biomechanical differences between forefoot striking and heel striking
  5. Tools to help assess potential benefits of learning to forefoot strike
  6. Transitioning safely to forefoot striking barefoot or in minimal footwear

Why Consider Foot Strike?

Humans and our recent ancestors have been accomplished endurance runners for more than a million years (Bramble and Lieberman, 2004). Our endurance running abilities may have evolved to enable our ancestors to engage in persistence hunting long before the comparatively recent invention of projectile technologies used for hunting purposes (Carrier, 1984Lieberman et al., 2009).
Our evolutionary history as runners partly accounts for why aerobic exercise is such a key component of human health. For most people, aerobic exercise involves endurance running, either jogging or playing aerobic sports such as soccer and basketball. Unfortunately, studies suggest that at least 30% of runners get injured every year, and many of these injuries stem from problems that arise in the foot or lower leg (van Gent et al., 2007).
Humans evolved to run and before the mid 1970s all humans ran in either no shoes or very minimal footwear such as sandals, moccasins or thin running flats. A basic prediction of evolutionary or Darwinian medicine is that the human foot is likely to be well adapted to running long distances barefoot. If so, then contrary to popular belief, the bare foot may be well suited for running long distances without requiring modern, heavily cushioned, high-heeled running shoes.
We do not know how early humans ran, but our research (Lieberman et al., 2010) indicates that humans were able to run comfortably and safely when barefoot or in minimal footwear by landing with a flat foot (midfoot strike) or by landing on the ball of the foot before bringing down the heel(forefoot strike). These kinds of foot strikes differ profoundly from heel striking both in terms of how the body is moving and the resulting forces on the body. Most runners who wear standard running shoes usually heel strike, but our research suggests that most barefoot or minimally shod endurance runners forefoot strike and sometimes midfoot strike. The following pages contain information about how these various strikes differ biomechanically and how they are relevant to how people run.
Nature Cover

Nature Cover

Watch the Video put together by Nature Publishing Group

Modern Running Shoes & Heel Striking

Some key features of the typical modern running shoe are:
Running Shoe - Cushioned Heel
  • Large, flared, cushioned heel:
    • Facilitates a comfortable and stable landing on the heel
    • Cushions some of the impact force caused by the foot’s collision with the ground
    • Distributes the impact force over a larger area of the rearfoot
Shoe Insert - Arch Support
  • Arch support and stiffening elements (e.g. medial post):
    • Many shoes prevent overpronation, which is the natural “rolling in” of the foot during stance (some shoes prevent oversupination or “rolling-out”)
    • Reduces the flattening of the foot's arch

Shod Runners Usually Heel Strike

Approximately 75% of shod runners heel strike (Hasegawa et al., 2007). While we do not know the definitive reasons why the majority of shod runners heel strike, we propose several potential explanations:
  1. It's comfortable. The shock-absorbing features cushion the force of impact. The graph below compares the forces that occur at the ground for a runner landing on the heel when barefoot (a) and in a running shoe (b). Note the initialimpact transient, a nearly instantaneous and large increase in force that occurs as the heel comes to a sudden stop upon impacting the ground. The shoe reduces the force by about 10% and slows the rate of loading considerably. This, in addition to distributing the impact force over a larger area of the rearfoot, makes it comfortable to heel strike.
  2. Thicker rearfoot cushioning than forefoot cushioning. This high heel makes it easier to heel strike because the sole below the heel is typically about twice as thick as the sole below the forefoot. So if your foot would tend to land flat when barefoot, it will land on the heel when in a shoe.
    Barefoot Heel Strike Ground Reaction ForceShod Heel Strike Ground Reaction Force

  3. It's stable. The shoe is designed to prevent too much movement such as pronation. This helps to make runners feel stable in modern shoes.

Is There Anything Wrong With Heel Striking in Running Shoes?

Not necessarily! Many people like to run this way and do so without injury. But some runners get repetitive stress injuries each year (estimates vary from 30-75%) and one hypothesis is that heel striking contributes to some of these injuries. We emphasize though, that no study has shown that heel striking contributes more to injury than forefoot striking. Read on to learn more about forefoot striking.

Running Before the Modern Running Shoe

Many people think modern running shoes are necessary in order to run safely and comfortably, but they were invented only in the 1970s. Before then, running shoes were just simple running flats that had little cushioning, no arch support, and no built-up heel. Humans were running for millions of years, apparently safely, in running flats, in thin sandals or mocassins, or in no shoes at all. Our research indicates that they may have been able to do so by forefoot or midfoot striking.
There are three major classifications of how a runner's foot strikes the ground:
Heel StrikingHeel lands first, then the forefoot comes down (heel-toe running)Barefoot Heel Strike
lateral view, barefoot
Shod Heel Strike
lateral view, shod
Midfoot StrikingHeel and ball of the foot land simultaneouslyVibram FiveFingers Midfoot Strike
lateral view, FiveFingers®
Vibram FiveFingers Midfoot Strike
medial view, FiveFingers®
Forefoot Striking*Ball of the foot lands first (usually below the 4th and 5th metatarsals) before the heel comes down (toe-heel-toe running)Barefoot Forefoot Strike
lateral view, barefoot
Vibram FiveFingers Forefoot Strike
medial view, FiveFingers®
*Forefoot striking as used here is distinct from forefoot striking in sprinters, in which the runner stays on the ball of the foot and the heel never comes down.
Note: some researchers classify foot strikes by the initial center of pressure. A rearfoot strike (heel strike) is an initial center of pressure in the back third of the shoe, less than 33% of the shoe's length; a midfoot strike is in the middle third, 34-67%; and a forefoot strike is in the front third, greater than 67%. We do not use this classification because it is designed mostly for shod running.

Shod Runners & Heel Striking

  • Approximately 75% of habitually shod runners all over the world heel strike (Hasegawa et al., 2007).

Elite Kenyan Forefoot StrikingBarefoot Runners & Forefoot and Midfoot Striking

  • Try running barefoot on a hard, natural surface, you’ll notice almost instantly that it hurts to heel strike! This is because the human heel pad cannot cushion much of the impact force (Ker et al., 1995; Chi and Schmitt, 2005) and this force is concentrated on a small area of the heel. Many shod runners asked to run barefoot in laboratory conditions (a treadmill or trackway) switch to a midfoot or forefoot strike.
  • Our research (Lieberman et al., 2010) indicates that habitual barefoot runnersuse all kinds of landings, but predominantly forefoot strike, even when going downhill. This is true of:
    • Runners who grew up without shoes or who wear thin rubber or leather sandals (e.g. Tarahumara ultrarunners, some Kenyan runners, and so on).
    • American barefoot runners who switched from wearing shoes to running barefoot or in minimal footwear.
    • Most western runners before the invention of the thick-heeled running shoe.

Adolescent Barefoot Kenyan Forefoot Strike

Our hypothesis is that until recently most humans had much more varied gaits; sometimes they landed on their heel, but more often they were midfoot or forefoot striking. We suspect that forefoot striking was most common.
Kenyan AdolescentThis individual has never worn shoes in his life
Adolescent Kenyan Running
Click the image to watch video

Elite Kenyan RunnerThis individual grew up running barefoot, but now wears shoes
Running Barefoot
Running in Shoes
Elite Kenyan Running Barefoot   Elite Kenyran Running in Shoes
Click the images to watch the videos
Note that this runner's leg is positioned in the same way at foot strike whether running barefoot or in shoes. When running barefoot this runner forefoot strikes. When running in shoes he has a midfoot strike. Without any apparent changes in the positioning of the runner's leg or foot, the wedged shape midsole of the shoe affects how the runner's foot contacts the ground.

Biomechanical Differences Between Different Foot Strikes

Why do Different Foot Strikes Matter?

Here we focus on the difference between heel striking and forefoot striking (see bottom of page for more on midfoot striking which is often intermediate). In heel striking, the collision of the heel with the ground generates a significant impact transient,a nearly instantaneous, large force. This force sends a shock wave up through the body via the skeletal system. In forefoot striking, the collision of the forefoot with the ground generates a very minimal impact force with no impact transient.
Therefore, quite simply, a runner can avoid experiencing the large impact force by forefoot striking properly.
The explanations below illustrate how and why a large collision is generated when heel striking and why such a small collision is generated when forefoot striking.

Heel Strikes and Ground Reaction Forces

Heel Strike Barefoot

Heel Strike in Running Shoes

Forefoot Strikes and Ground Reaction Force

Forefoot Strike Barefoot

Forefoot Strike in Racing Flats

Forefoot Strike in Standard Running Shoes

To understand these differences, we need to explore the biomechanics of running, which can be divided into two major components: running kinematics, the way in which the body moves, and running kinetics, the relationship between movements and the forces that cause them. To understand the important kinetic differences between different kinds of foot strikes we will first consider key differences in running kinematics. Note that there is a continuum of different kinds of landings from landing on the heel (heel striking), landing simultaneously on the heel and ball of the foot (midfoot striking), and landing on the ball of the foot (forefoot striking). Again, for simplicity, we focus here on heel and forefoot striking, noting that midfoot striking is often intermediate.

Running Kinematics


Heel Striking

Forefoot Striking

Moment of ImpactBarefoot Heel Strike Barefoot Forefoot Strike 
Hip and knee are flexed.
Ankle is dorsiflexed (toes point up).Ankle is plantarflexed (toes point slightly down). Foot is usually slightly inverted (the sole is angled inwards).
Land on the middle to outside of the heel just below the ankle joint.Land on outside of the forefoot (the ball of the foot, just below the 4th and 5th metatarsal heads).
As you land, the ankle begins to plantarflex (toes move towards the ground).As you land, the ankle begins to dorsiflex (heel moves towards the groud).
Arch of the foot is not loaded.Arch of the foot is loaded and begins tostretch/flatten.

Foot Flat
Barefoot Heel Strike

Barefoot Foot Flat
Barefoot Forefoot Strike

Barefoot Foot Flat
Knee and hip flex.
As the ankle plantarflexes, the forefoot comes down.As the ankle dorsiflexes, the heel comes down under the control of the calf muscles and Achilles tendon, which are stretching.
Foot Flat 

Barefoot Foot Flat

Barefoot Midstance
Barefoot Foot Flat

Barefoot Midstance
Knee and hip continue to flex.
The ankle dorsiflexes as the lower leg moves forward relative to the foot and the foot everts (rolls inward).
Now that the whole foot is on the ground, the archbegins to stretch/flatten.The arch continues to stretch/flatten.
This combination of eversion, ankle dorsiflexion and arch flattening is called pronation.This combination of eversion, ankle dorsiflexion and arch flattening is called pronation, but occurs in the reverse direction compared to heel striking (from the forefoot to the rearfoot not heel to toe).

Toe Off
Barefoot Midstance

Barefoot Toe Off
Barefoot Midstance

Barefoot Toe Off 
Ankle plantarflexes bringing the heel off the ground (calf muscles and Achilles tendon now shorten).
Foot’s arch recoils, and the toes flex.
These actions push the body upwards and forwards for the next stride.

Running Kinetics and Impact Forces

The physics of collisions: The impact of the body with the ground generates an impact force, which equals mass times acceleration (ma, Newton’s 2nd Law). The mass involved in this collision is whatever portion of the body that comes to a dead stop along with the point of impact on the foot (this is called the effective mass). The acceleration is the rate of change of this mass' velocity. Because the impact occurs over a brief period of time, the force times the duration of the collision, called theimpulse, is the effective mass times its change in velocity over the duration of the impact. For a detailed explanation of the physics, see equation 1 in Lieberman et al (2010).

Heel Striking

Forefoot Striking

Effective Mass at ImpactFoot and lower leg come to a dead stop at impactwhile the rest of the body continues to fall above the knee.Forefoot comes to a dead stop, but the heel and lower leg continue to fall (in a forefoot strike). Theankle flexes (in both forefoot and midfoot strikes).
Effective mass is approximately the foot plus the lower leg, which equals 6.8% of total body mass in the runners measured in Lieberman et al. (2010).Effective mass is the forefoot and some portion of the rearfoot and leg, which equals 1.7% of total body mass in the runners measured in Lieberman et al. (2010).
Change in Velocity at ImpactThe change in velocity of the effective mass is the difference between the velocity of the falling foot at the instant before contact and the velocity just after contact, which is zero. This change in velocity does not differ significantly between a heel strike and a forefoot strike.
Conversion of Vertical Momentum at ImpactAlthough the ankle may flex a little (plantarflex) during the impact period, the vertical momentum of the lower leg is mostly absorbed by the vertical component of the collision force.Much of the vertical momentum of the rearfoot and lower leg is converted into rotational momentum.
Analogy: It is like dropping a rod straight down on its end: it comes to a sudden, loud stop.Analogy: It is like dropping a rod on its end at an angle: there is a sudden stop at one end of the rod, but it is much less loud because the rest of the rod continues to fall as it topples over.
Impact ForceThis kind of collision leads to a rapid, high impact transient about 1.5 to as much as 3 times your body weight (depending on your speed) within 50 milliseconds of striking the ground (see graph a below).

This is equivalent to someone hitting you on the heel with a hammer using 1.5 to as much as 3 times your body weight. These impacts add up, since you strike the ground almost 1000 times per mile!

Many running shoes make heel strikes comfortable and less injurious because they slow the rate of loading considerably, reduce the force by about 10% (seegraph b below) and spread this force out over a greater area of the foot. But they do not eliminate the impact transient.
This kind of collision produces a very slow rise in force with no distinct impact transient. There isESSENTIALLY NO IMPACT TRANSIENT in a forefoot strike (see graph c below). The same is true of some (but not all) midfoot strikes.

We have found that even on hard surfaces (a steel force plate) runners who forefoot strike have impact forces that are 7 times lower than shod runners who heel strike. Rates of loading are equal to or less than rates of loading for shod runners.
Figure 1a
Figure 1b
Figure 1c
Note that the peak force at midstance is the same for both kinds of gaits. This peak reflects the ground reaction force when the body's center of mass is at its lowest point. Because peak force at midstance rises slowly, it is probably less related to injury.

A Note on Midfoot Strikes

Some runners land simultaneously on the ball of the foot and the heel. Midfoot strikes represent a continuum between heel strikes and forefoot strikes, depending on where the center of pressure is at impact and how stiff the ankle and knee are during impact. One can land softly in a midfoot strike without much impact transient, but some midfoot strikes can generate impact transients like those of heel strikes. However, these forces are distributed over larger surfaces areas, reducing the stress on the foot.

Running Barefoot, Forefoot Striking & Training Tips

Forefoot Striking & Impact Forces

For millions of years, it is likely that runners landed with no single, specific foot strike, and rather landed with a variety of foot strikes including forefoot, midfoot and heel strikes, but we suspect that the most common form of foot strike was a forefoot strike. Midfoot strikes were probably also more common than they are today. These kinds of strikes (i.e. landing first on the lateral ball of the foot) lead to lower impact forces which may lead to lower rates of injury. We hypothesize and there is anecdotal evidence that forefoot or midfoot striking can help avoid and/or mitigate repetitive stress injuries, especially stress fractures, plantar fasciitis, and runner's knee. We emphasize, however, that this hypothesis on injury has yet to be tested and that there have been no direct studies on the efficacy of forefoot strike running or barefoot running on injury.

Forefoot Striking Barefoot:
Produces Minimal Impact Force with No Impact Transient

Heel Strike in Shoes:
Produces Significant Impact Transient

Other Advantages of Forefoot Striking Barefoot or in Minimal Footwear

  • Bare FeetIt strengthens the muscles in your foot,especially in the arch. A healthy foot is a strong foot, one that pronates less and is less liable to develop a collapsed arch.
  • It may cost less energy to forefoot strike because you use the natural springs in your foot and calf muscles more to store and release energy. Running barefoot or in minimal footwear (usually lighter than traditional running shoes) means that there is less mass to accelerate at the end of the runner's leg with each stride. Running barefoot has been shown to use about 5% less energy than shod running (Divert et al., 2005; Squadrone and Gallozzi, 2009).
  • Barefoot running feels great! Your feet have lots of sensory nerves. And because there is minimal impact forces on landing it can be very comfortable provided you develop calluses on your feet (see below).

Disadvantages of Forefoot Striking Barefoot or in Minimal Footwear

  • Thick-soled shoes are much more forgiving when running over glass, sharp objects, ice and so on.
  • If you have been a heel striker, it takes some time and much work to train your body to forefoot or midfoot strike, especially because you need stronger feet and calf muscles. Runners may be at greater risk of developing Achilles tendonitis when they switch from heel striking to forefoot or midfoot striking (see training tips below).


  • First and foremost, the information provided here is for educational and informational purposes only, and is not a substitute for advice from a physician, trainer or coach. We strongly encourage you to consult a physician before implementing any exercise program. We accept no liability for the information provided below. Please see User Agreement.
  • Whatever you do, don't overdo it! If you have been a heel striker most of your life, it will take lots of work to switch to forefoot striking. If you develop lasting pain, stop and consult a physician.
  • Minimal Shoes. A great way to learn to forefoot strike is to try it first barefoot on a hard but smooth surface like a tennis court, a track or even a smoothly paved road. Your body will quickly tell you what to do! But until you develop good form and build up calluses on your feet, you’ll want to wear minimal footwear to forefoot strike. There are many minimal shoes with several features that allow you to forefoot strike:
    • No built up heel. If the heel is too large, then you’ll have to overpoint your toes, which might cause pain and damage to the foot.
    • A flexible sole and no arch support. A stiff sole and arch support will prevent the natural flattening of the arch, preventing the muscles and ligaments of the foot from functioning as they were meant to. If you can’t easily twist and bend the sole of the shoe, then it is probably too stiff. At first this will work out and tire the muscles of your foot, but eventually with progressive training the muslces will strengthen.

Tips on Proper Forefoot or Midfoot Strike Form

There is no single “perfect running form.” Everyone’s body is different and no single technique could be best for everyone. Here are some general tips:
  • A good landing should feel gentle, relaxed and compliant. You typically land on the ball of your foot towards the lateral side. After the front of your foot lands, let the heel down gradually, bringing the foot and lower leg to a gentle landing as you dorsiflex your ankle under the control of your calf muscles. It's like when you land from a jump, flexing the hip, knee and ankle. Again, the landing should feel soft, springy, and comfortable. It's probably good to land with the foot nearly horizontal so you don't have to work the calves too much.
  • Do not over stride (land with your foot too far in front of your hips). Over striding while forefoot or midfoot striking requires you to point your toe more than necessary, adding stress to the calf muscles, Achilles tendon, and the arch of the foot. It often feels as if your feet are striking the ground beneath your hips. It is similar to the way one’s feet land when skipping rope or when running in place (as runners sometimes do when waiting to cross a street).
  • A good way to tell if you are landing properly is to run totally barefoot on a hard, smooth surface (e.g. pavement) that is free of debris. Sensory feedback will quickly tell you if you are landing too hard. If you run barefoot on too soft a surface like a beach, you might not learn proper form.

Experienced Barefoot Runner Forefoot Striking

Kenyan Adolescent Who Has Never Worn Shoes

Tips on Transitioning to Forefoot or Midfoot Striking

Forefoot striking barefoot or in minimal footwear requires you to use muscles in your feet (mostly in the arch) that are probably very weak. Running this way also requires much more strength in your calf muscles than heel striking because these muscles must contract eccentrically (while lengthening) to ease the heel onto the ground following the landing. Novice forefoot and midfoot strikers typically experience tired feet, and very stiff, sore calf muscles. In addition, the Achilles tendon often gets very stiff. This is normal and eventually goes away, but you can do several things to make the transition successfully:
  • Build up slowly! If you vigorously work out any weak muscles in your body, they will be sore and stiff. Your foot and calf muscles will be no exception. So please, don’t overdo it because you will probably injure yourself if you do too much too soon. 
    • Start by walking around barefoot frequently.
    • First week: no more than a quarter mile to one mile every other day.
    • Increase your distance by no more than 10% per week. This is not a hard and fast rule, but a general guide. If your muscles remain sore, do not increase your training. Take an extra day off or maintain your distance for another week.
    • Stop and let your body heal if you experience pain. Sore, tired muscles are normal, but bone, joint, or soft-tissue pain is a signal of injury.
    • Be patient and build gradually. It takes months to make the transition.
  • If you are currently running a lot, you don’t need to drastically reduce your mileage. Instead, supplement forefoot or midfoot striking with running the way that you normally ran before beginning the transition. Over the course of several months, gradually increase the proportion of forefoot or midfoot striking and reduce the proportion of running in your old style. Use the same 10% per week guideline in increasing the amount of running you do forefoot striking.
  • It is essential to stretch your calves and hamstrings carefully and regularly as you make the transition. Massage your calf muscles and arches frequently to break down scar tissue. This will help your muscles to heal and get stronger.
  • Listen to your feet. Stop if your arches are hurting, if the top of your foot is hurting, or if anything else hurts! Sometimes arch and foot pain occurs from landing with your feet too far forward relative to your hips and having to point your toes too much. It can also occur from landing with too rigid a foot and not letting your heel drop gently.
  • Many people who run very slowly find that forefoot striking actually makes them run a little faster.


  • Land gently on your forefoot and gradually let the heel come down
  • Transition slowly
  • Stretch your calves and Achilles tendon
  • Don’t do anything that causes pain
  • Listen to your body and run totally barefoot to learn good form
  • Buy minimal shoes that lack high heels and stiff soles
  • Consult a doctor

Frequently Asked Questions

What about surface hardness? Our ancestors didn’t run on pavement.
A common perception is that running on hard surfaces causes injuries, but runners typically adjust leg stiffness so they experience the similar impact forces on soft and hard surfaces. Further, forefoot and some midfoot strikers hit the ground in a way that generates almost no collision forces even on hard surfaces like steel. You can run barefoot and heel strike on a soft beach or lawn, but most natural surfaces are much harder and rougher. With proper forefoot or midfoot strike form, running on hard, rough surfaces can be comfortable and safe.

What is minimal footwear?
We define minimal footwear as any footwear that lacks high cushioned heels, stiff soles and arch support. If you want to try, there are a few things you might look for in minimal footwear for running:
  • The thickness of the cushioning in the rearfoot and forefoot should be about the same, and not too thick.
  • You should be able to easily twist the shoe along the long axis and bend the shoe at the midfoot.
  • There should not be a stiff arch support that prevents the natural movement of the arch of the foot.

How do I get started?

It is very important, in fact critical that you follow a slow progression when you transition to forefoot striking. Even with such a program, you will likely experience some muscle soreness in your calf, lower leg and feet. If you progress too quickly, you risk causing injury to your muscles or tendons. See our recommendations for getting started in Training Tips.

Should I run barefoot in the cold?

Please, don't run barefoot when your feet are numb from the cold. When your feet have lost sensation, you will not be able to notice damage that you may be causing to your feet until it is too late. In cold conditions, minimal footwear can offer protection, especially if you wear them with toe socks.

Who should NOT run barefoot or in minimal shoes?

Anyone who has sensory loss to the foot should not run barefoot. In fact, these individuals should probably wear shoes of some type at all times in order to protect their feet. Additionally, individuals with significant foot deformities that affect gait mechanics should avoid barefooting or running in minimal shoes. If you have any foot-related problems, you should seek the advice of a medical professional before you start barefoot running.

What surfaces should I run on?

Choose a clean smooth paved surface. A common perception is that our feet were not meant to run on hard surfaces and that running on hard surfaces causes injuries. But our ancestors ran on surfaces of various hardness and forefoot striking when barefoot has less impact than even walking. Runners typically adjust leg stiffness so they experience the same impact forces on soft and hard surfaces (Dixon et al., 2000).

What happens if I land on a pebble or other debris?

It hurts! But, as long as you are running in daylight, you should be able to see and avoid any debris that might be in your path. However, if you happen to land on a small pebble, you will naturally unload and minimize the pain. Use sound judgment in deciding where and when it is appropriate to run completely barefoot.

Will my feet become callused?

While the skin on your feet may become slightly thicker with barefoot running, the pavement acts as a pumice stone and helps to minimize too much callusing. You'll find that calluses form most especially on the ball of your foot.
What if I want to wear shoes?

By all means, wear shoes if you want to! You can still reduce your impact forces by utilizing a forefoot of midfoot strike pattern. This is easier if you pick a shoe that will allow your foot to function as naturally as possible (and, fortunately, many such shoes are available).

Do barefoot runners get injured less?

Barefoot runners often adopt forefoot or midfoot strike gaits and have a softer, more gentle landing, which may reduce their risk of injury. While there are anectodal reports of barefoot runners being injured less, there is very little scientific evidence to support this hypothesis at this time. Well-controlled studies are needed to determine whether barefoot running results in fewer injuries.

Is barefoot walking beneficial?

Probably. Even if you are not a runner, walking barefoot can help to strengthen the muscles of the foot and ankle. And if you are a runner, strengthening these muscles will allow you to run better barefoot.

Should I avoid a heel strike when walking barefoot?

This is not an issue we have studied yet much, but our observations are that its totally normal to heel strike when walking, even when barefoot. That said, barefoot walkers often walk with a less pronounced heel strike or more of a midfoot strike. One study has shown that heel strike walking is more efficient than forefoot strike walking.

More questions?
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