Why do Kenyans dominate the sport of distance running? Take, for example, Kenyan Wilson Kipsang -in the 2013 Berlin Marathon, he ran the fastest time in history: 2 hours, 3 minutes and 23 seconds. That’s an average of 4:42 per mile. 8 of the 10 fastest marathons on record were won by a Kenyan. Since 1988 there have been 20 Kenyan male winners of the Boston marathon alone. In this year’s NY Marathon, Kenyans were the victors in both the male and female divisions. There have only been 17 American men in history of our large powerful country to run a sub 2 hour 10-minute marathon while 32 Kenyans had no problem completing this feat in one single month – October 2011. What makes them such outstanding and dominating distance runners? Continue readingby
Here is a thought experiment: Imagine spending less time working out and getting more fit. How would that make you feel? Of course this would be great, right? Unless, you’re one of those rare humans who enjoy spending hours toiling away in the gym reading gossip magazines as you go through your daily calisthenics. I, on the other hand, want more bang for my buck wasting no time in the gym. In two well done scientific studies published in the 2013 February issue of The Journal of Physiology, the researchers describe their recent discoveries “that three sessions of sprint interval training (SIT), taking just 90 min per week, are as effective as five sessions of traditional endurance exercise, taking five hours per week, in increasing whole body insulin sensitivity via two independent mechanisms”. Sprint interval training has also been shown to produce superior cardiovascular and weight loss effects when compared to long steady state cardio training (SST). The really amazing thing is SIT provokes these advantages in less half the time. Additionally, sprinting, not jogging, has shown to decrease belly fat faster and utilizes glucose more efficiently preventing it from being stored as fat. Continue readingby
There are several pros and cons of running outdoors versus on treadmill. It is hard to say which is ‘better’, nevertheless they are not equal. The treadmill is a beautiful piece of cardio machinery but I can’t help but feel like some overgrown gerbil when I’m on one. There are many different kinds of designs. The high-end gym models cost upwards of 9k. It is the most popular piece of equipment in health clubs for a reason, it burns a lot of calories and produces a great workout. However, it is not equivalent to running outdoors. Biomechanically these are two very different activities. In fact, when comparing similar speeds and grades, some studies show outdoor running burns more calories. Let’s examine why free-range running may be superior (in many but not all ways) to treadmill running.
Weight loss is a multi-factorial process that is not fully understood. That being said, science concludes there are 6 major factors that affect weight loss:
6- Activities of daily living
Obviously there is not much you can do about genetics, that boat sailed long ago, blame your parents. The rest of these items are on the table. As I am sure you are aware, all of these factors are interrelated, some more than others. I’d like to focus on diet, exercise and activities of daily living because they are the major factors in energy conversion. A goal of weight loss is to use more energy than you take in. Balancing bodily energy is a lot more complicated than calories in (food we eat) and calories out (exercise and activities of daily living). Calories eaten and subsequently used during voluntary movements are only two small parts of the energy equation and insignificant by themselves. Your total energy expenditure fluctuates daily and is quite difficult to accurately measure. Most of your calories are spent on metabolic processes:
- calories are burned during all involuntary movements (breathing, heart beat etc.)
- heating the body due to environmental temperatures
- calories are used in bone and soft-tissue growth
- the largest caloric drain on the body comes from brain functions
- metabolism of food
- calories used on a everyday basis to combat infections
- tissue restoration
Everyone burns calories at a different rate. Furthermore, many people are better adapted for certain exercises/movements and burn less energy when performing those tasks. If Micheal Moore challenged Lance Armstrong to a bike race, not only would Mr. Moore lose the race, he’d probably burn a lot more calories too. Mr. Armstrong’s body has specifically adapted to biking and has become extremely efficient in that movement pattern (and his VO2 max, resting heart rate, recovery heart rate, lactic acid threshold, body weight, muscle mass etc. are all much better than Moore’s – this is just a guess) thus using less energy.
There is no one best form of aerobic exercise or machine that burns the most calories. According to Kravitz and Robergs, “based on the fundamental principles of indirect calorimetry, to burn more calories during exercise you need to increase oxygen consumption. The issue of exercise and caloric expenditure is as simple as that.” Research shows the greatest impact on caloric expenditure during exercise comes from contraction of skeletal muscles which therefore increases oxygen uptake. The more oxygen you need during exercise the more calories you burn. Listed below are the other factors during exercise that play a role in calorie burn:
- the amount of muscle fibers being used
- complexity of the movement
- prior experience with the exercise
- weight bearing exercise vs. non-weight bearing
- balance and proprioception requirements
- resistance and incline of machine
- your total body weight (the heavier you are the more calories you burn)
- the amount of lean muscle mass you have
- speed and intensity level
- duration of the exercise
- temperature of the room (colder rooms will induce higher energy demands)
Please keep in mind that any one of the machines listed below are capable of inducing a higher caloric expenditure than the other. This list is an estimation of which cardio machines have the potential of burning the most amount of calories when all other factors are equal:
- Cross Country Skiing
- Running on the treadmill
- Step-Mill (the one with real steps)
- Elliptical with Arms
- Jump Rope
- Biking upright
- Recumbent biking
- Arm ergonometer
Most people benefit from switching aerobic machines once every 8 weeks. This is the approximate time it takes to adapt to a new movement skill. As your body becomes more and more familiar with the specific exercise you burn less calories due to neuromuscular efficiencies. Another reason to switch every two months (or more) is to prevent linear wear patterns from developing within your joints. This is especially true in regards to fixed foot position machines like the elliptical or bike. Perhaps try something new like hiking, jump roping, kickboxing, trail running, swimming etc. Depending on your goals, it may be a good idea to alter the speed, incline and resistance of the exercise you choose.
1. McARDLE, W.D. et al. (2000) Energy expenditure at rest and during physical activity. In: McARDLE, W.D. et al., 2nd ed. Essentials of Exercise Physiology, USA: Lippincott Williams and Wilkins.
2. DAVIS, B. et al. (2000) Physical Education and the Study of Sport. UK: Harcourt Publishers Ltd.
3. MayoClinic.com; Exercise for Weight Loss; 2009
4. Borg G.A.V. Psycholphysical bases of perceived exertion. Med. Sci. Sports Exerc. 14:377-381, 1982.
5. Toner, M.M., Glickman, E.L., & McArdle, W.D. Cardiovascular adjustments to exercise distributed between the upper and lower body. Med. Sci. Sports. Exerc. 22:773-778, 1990.
Humans have been running/walking barefoot (and in minimal footwear) for about two million years. It is our natural state. Our feet evolved to function without footwear. Shoes often abuse our poor misaligned, claustrophobic feet. It is almost hard to believe we treat the foot, which literally unites us to the earth, so badly. I admit, some of us go through lots of hoops drawing attention to our feet. With pretty pedicures, high-end heels (4 inch Christian Louboutins) and trendy sneakers that cost over $500 (think Prada) our feet would, on the surface, seem pampered. Not the case by a long shot, so say I. We jam shoes on our children the minute after they take their first steps. From that point on, we barely take them off until the day we die (and some of us are even buried with shoes!).
Ever try to put a shoe on a baby or the even family dog? They can hardly remove the offending shoe or booty fast enough. It is actually quite funny and frustrating to watch. It is an instinct to be barefoot. Until about age 10, most children still have soft, malleable feet. Not to mention they are getting larger all the time and literally pushing up through the seams. Kids’ feet are not just smaller versions of ours; they tend to be wider across the toes and mostly cartilage (which is gradually replaced by bone). Children’s footwear is modeled to be smaller versions of adult ones. Most shoe companies design shoes with pre-defined shapes and overlook the natural architecture of the human foot. This is especially true when it comes to shoes for kids. Rigid and malformed shoes directly affect how a child’s foot bones and arch will shape. Our toes are supposed to be spread out, almost in a “v” shape. Instead most of us have crunched and smooshed in feet with little or no independent control of our toes. Our feet become the shape of the shoes we wear.
For a variety of reasons, sneaker companies are always convincing us to buy snug fitting shoes for our toddlers (and us). A growing child’s foot will get all of its developmental requirements satisfied by simply playing, jumping and running without shoes.
Udaya B. Rao, Benjamin Joseph, (1992) “The influence of footwear on the prevalence of flat foot: A survey of 2,300 children”, Journal of Bone and Joint Surgery, Vol. 74‚ No. 4. pages 525-527.
- Findings: An Elevated heel of any height on a child’s shoe shortens the Achilles tendon. This marks the beginning of permanent tendon shortening. Flat foot was most common in children who wore closed-toe shoes, less common in those who wore sandals or slippers, and least in the unshod. The study suggest that shoe-wearing in early childhood is detrimental to the development of a normal longitudinal arch.
Dr William A Rossi, (2002) “Children’s Footwear: Launching Site for Adult Foot Ills”, Podiatry Management, pages 83-100.
- Findings: Slimmer and more flexible children’s shoes do not change foot motion as much as conventional shoes and therefore should generally be recommended for healthy children.
When my son isn’t running around barefoot, he rocks a pair of pink or aqua blue VIVOBAREFOOT shoes. He also wears “zero drop” sandals like Huraraches or scuba socks. In looking for shoes it is important to find a pair that has no heel, thin soles, lightweight and a big toe box. Let your feet feel the ground and function like they were evolved to work.
I really love this next video. It is a grainy copy of Alan Watts, an intellectual eastern philosopher from the 70’s (and yes, he did like his LSD), pontificating on ideas of work and play in relation to running:
The modern running sneaker and walking shoe has wrecked havoc on the human foot. They have several common construction features that pose potential dangers. In my opinion, these three features listed below are the most pernicious.
- Shortened and weakened calf musculature
- Excessive strain on the plantar fascia and Achilles tendon
- A body weight shift forward which changes your natural upright posture
- Increased impact forces -because you have to step down harder in order to feel the ground
- Longer strides in front of your center of gravity which increases the shear forces on your knees, hips and ankles
- Reduces the shock absorbing and elastic properties of your arches
- Toes cannot naturally splay out (a function for balance and proprioception) when you step down
- Toe joints stay in an extended position which can lead to adaptive shortening
- Toe dexterity is weakened
- It may lead to hammer toes and/or bunions
- Crowds toes which in time may cause permanent faulty alignment
- Flexing motion (gripping) of the MTP joints are weakened (specifically the big toe)
- Toes are meant to grip the ground. The curved “toe springs” hold your toes up preventing most gripping action
- The first MTP (big toe) is restrained from doing its natural push-off and in turn causes a “roll” off the forefoot and/or pivot on the smaller MTPs.
- Prevents natural pronation
- Inhibits normal function of your arch
- Increases compensatory patterns, which may weaken the foot and knee
- Increases your chances of spraining an ankle
Since the advent of the modern running shoe in 1972 (Nike) we have not seen injuries rates go down, in fact some studies have shown they have gone up. Yet somehow sneaker companies have been spending billions of dollars on marketing, research and development to make “better shoes” (Honestly, I don’t believe in a grand conspiracy by the shoe companies to hobble society….their motives are more simple, produce shoes that turn a profit). In a paper for the British Journal of Sports Medicine in 2008, researchers revealed there are no evidence-based studies that demonstrate running shoes make you less prone to injury. Not a one! In fact, there are some studies that show heavily cushioned expensive footwear causes more injuries than their inexpensive less cushioned counterparts! The impact on your joints while running can be several times your body weight and a heel cushion will do little to ameliorate those forces. “You can cover an egg with an oven mitt before rapping it with a hammer, but that egg ain’t coming out alive.”- Christopher McDougal author of “Born to Run”.
Steven E. Robbins and Gerard J. Gouw. “Athletic footwear: unsafe due to perceptual illusions,” Medicine and Science in Sports and Exercise, 23(2), 1991, pp. 217-224.
- Findings: Wearers of expensive running shoes that are promoted as having additional features that protect (e.g., more cushioning, ‘pronation correction’) are injured significantly more frequently than runners wearing inexpensive shoes (costing less than $40)”.
- Findings: Shows that runners who wear top of the line shoes are 123% more likely to get injured than runners in cheap shoes (which have less cushioning and support).
The pictogram below shows the correct way to walk barefoot. When you walk with shoes your gait changes. However, you can learn to walk better in shoes by re-learning some basic skills:
According to research by Harvard professor Dr. Dan Lieberman, humans evolved into expert barefoot endurance runners out of necessity. His research makes a cogent argument for the normalcy of human barefoot running. As animals we are pitifully slow sprinters. This is how we compare:
Cheetah – 70 mph
Antelope – 61 mph
Deer – 30 mph
Cat – 30 mph
Greyhound dog – 39 mph
Horse – 55 mph
Usain Bolt – 27 mph (fastest human on record but most of us are topping out at the blistering speed of 14-17 mph)
Due to our anatomy and bipedal nature we are exceptionally capable of endurance. It is widely accepted that humans are the best long distance runners in the entire animal kingdom. Our survival as hunter-gatherers depended on our ability to outwit, chase and catch prey. Moreover there is scant evidence that shows humans used projectile weapons until fairly recently (about 50k years ago). Therefore, we most likely used our bigger brains and better endurance skills to catch prey. Persistence hunting (which seems totally insane on the surface) is the practice of running down and tracking prey, usually over long distances, to the point of the animals’ total exhaustion. In some cases the animal drops dead of fatigue or submits to capture. A few tribes around the world still practice this skill. Obviously this was not our only way (or even primary way) of getting food. Lieberman’s theory shows how barefoot humans probably ran long distances to survive. The ones who were most successful hunters and least injured lived to become our ancestors.
Running barefoot is not for everyone. If you have foot abnormalities and/or dysfunctions you may not benefit from being barefoot. Perhaps you are one of the few, lucky, avid runners who are injury free? If that is the case, I wouldn’t change a thing. Stick with what works. On the other hand, if you are interested in running barefoot you will need to stick to a progression schedule and re-learn the skill. In my next post I will document the process.
Check out these three slo-mo videos of barefoot running vs. sneaker running:
I have a love affair with skepticism and contrarianism thus compelled to detail the primary arguments against barefoot running. Until more research is available, it’s hard to prove sneakers are outright harmful for most people. Here are the pros and cons often discussed and observed in regards to barefoot running/walking:
1- Just because barefoot running and walking is a “natural” part of human locomotion doesn’t mean it is good. The animal kingdom is rife with examples of animals that evolved detrimental traits. Including Homo Sapiens and our damned appendix, wisdom teeth, male nipples etc.
2- There is a lack of research showing barefoot running is less injurious than shod running. In fact some studies show that barefoot running (and heel striking) can be more deleterious.
3- Debris and sharp objects may bang up and cut your feet (this is why people wear minimal shoes).
4- My feet will get dirty and callused. I can definitely attest to this one.
5- Barefoot running hurts. (If you are taught correctly and break in slowly, it should not hurt but a little discomfort is expected).
6- It is just a fad (albeit a two million year old fad).
7- Due to deformities and or prior injuries some people will not benefit from barefoot running/walking and may in fact cause themselves further injury.
8- Habitually barefoot feet are much different looking than our pampered western feet. The foot is usually bigger, with no discernible arch, splayed toes, leathery soles and all around Hobbit-like.
(The research on the benefits of barefoot running/walking is inconclusive yet below I list some anecdotal and scientifically observed advantages of natural barefoot running):
1- Strengthens the foot’s arch and toes
2- Helps elongate one’s calf musculature and increase the flexibility in the ankle complex
3- Improves the foot’s dexterity
4- Improves the lower leg and foot’s proprioception
5- Can help people improve their running times
6- It costs less energy (the weight of the shoe can drastically change your gait and increase your metabolic demands) and therefore may allow you to run longer
7- It helps you become more aware of your surroundings (and closer to nature) and improve the tactile feeling in your feet
8- Less bad forces put upon your lower leg and foot
9- You can spread and expand your feet more, giving greater control to the foot musculature
10- Foot ailments like bunions, hammertoes, ingrown toenails and neuromas may be prevented by living barefoot
11- Balance and coordination may be improved
12- Societies that live barefoot enjoy almost injury free running and suffer very little from common Western foot ailments (BUT, these societies tend to lack Park Avenue sports medicine doctors and podiatrists—remarkably there are very few complaints of ingrown toe nails (etc) and the medical data is even more uncommon!).
13- It is just more fun and so cool to be barefoot! (this is, of course, a peer-reviewed scientific fact 🙂
In the case you are a data wonk, listed for your perusal are a few more important studies documenting the benefits of barefoot running (and yes, I could also provide you with studies depicting the advantages of athletic shoes — but most seem to be sponsored by Nike, Reebok, Asics, etc.):
1- Robbins, S; Hanna A (1987). “Running-related injury prevention through barefoot adaptations”. Medicine and Science in Sports and Exercise 19 (2): 148–156.
- Findings: Analyzed the longitudinal (medial) arch of 17 habitually shod runners and how it changed when they trained barefoot over a period of 4 months. It was found that this arch decreased in length by an average of 4.7mm. Authors contend this change is due to activation of foot musculature when barefoot that is usually inactive when shod. They maintain that foot musculature allows the foot to dampen impact and remove stress from the plantar fascia.
- Findings: Shows that compared to running barefoot, running in conventional running shoes increases stress on the knee joints up to 38%, although whether this leads to higher rate of heel injuries is still not clear
- Findings: Kinematic and kinetic analysis show that even on hard surfaces, barefoot runners who forefoot strike generate smaller collision forces than shod rear-foot strikers. Forefoot and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
- Findings: Stride frequency, anterior-posterior impulse, vertical stiffness, leg stiffness, and mechanical work were significantly higher in barefoot condition compared to shod. Net efficiency, which has metabolic and mechanical components, decreased in the shod condition. The mechanical modifications of running showed that the main role of the shoe was to attenuate the foot-ground impact by adding damping material. However, these changes may lead to a decrease of the storage and restitution of elastic energy capacity, which could explain the lower net efficiency reported in shod running.
- Findings: Increased joint torques at the hip, knee, and ankle were observed with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.