With the release of Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen, Christopher McDougall’s book about the Tarahumara Indians of Copper Canyon in Mexico (Knopf 2009), interest in barefoot running has soared. The author himself became
curious about this type of running as a
potential means of improving foot strength and running mechanics in order to become more competitive in ultramarathons (50-kilometer and 50-mile distances).
This new awareness of barefoot running has prompted many exercise professionals to integrate some barefoot training into clients’ programs. This column reviews running popularity, injuries and injury prevention strategies, and presents a number of barefoot training program ideas.
For many, running produces a feeling of well-being (Macera 1992). As tired and fatigued as one may feel before a run, there is often a satisfying mood improvement afterward (Morris & Salmon 1994). Many people experience feelings of euphoria and stress relief following a good run. A great number of enthusiasts participate in running for disease prevention and body weight management. According to the National Sporting Goods Association (NSGA), 35.9 million people (≥ 7 years old) participated in running and jogging in 2008, an 18% increase over 2007 (NSGA 2009).
Despite the increasing popularity of running, the incidence of injuries remains high. Lun et al. (2004) tracked musculoskeletal injuries in 87 recreational runners (44 men, 43 women; aged ≥ 18 years) for 6 months. Subjects were running more than 20 km per week (~12.5 miles per week) and had no injury at the start of the study. Among both sexes, 79% of subjects suffered at least one lower-limb injury during the study. In a review of 172 relevant articles on running injuries, van Gent and colleagues (2007) note that running injuries occur most commonly at the knee (7%–50%), followed by the lower leg (9.0%–32.2%), the foot (5.7%–39.3%) and the upper leg (3.4%–38.1%). Macera (1992) observes that the biggest predictor of running injuries is running distance. Van Mechelen (1992) supports this evidence, concluding that 50%–
75% of injuries are due to overuse, the constant repetition of the impact from running. Cavanagh and Lafortune (1980) point out that the impact force of running is up to three times the runner’s body weight. To lower injury risk, Macera recommends less than 32 km (~20 miles) of running per week.
Pronation—the turning of the foot at the ankle, during which the inside arch flattens to absorb force—has also been identified as a key factor related to running injuries (Hart & Smith 2008). Cavanagh and Lafortune (1980) explain that the internal forces during the foot strike in running place the foot into pronation. As the body shifts over the foot, the foot motion changes to supination (slight outward rolling of the foot), which increases the rigidity (stability) of the foot during the push-off phase. Runners who overpronate may have more ailments that affect the foot, ankle, knees and hips.
Orthotics, cushioning footwear and shock-absorbing running surfaces (such as treadmills with flex decks or cushion suspension systems) are common interventions used to reduce extremity injury risk from running. There is convincing evidence that properly fitted orthotics are effective for reducing lower-extremity pain and injuries (Mündermann et al. 2003). Hart and Smith (2008) note that research is conflicting on whether footwear cushioning meaningfully dampens impact forces. In fact, subjects tend to adapt their foot-loading technique during running when wearing hard- and/or soft-shoe midsoles, often neutralizing the effect of the shoe cushion.
Suspension or flex deck treadmills are promoted to allow exercisers to run at relatively higher intensities with less-than-usual lower-body discomfort. Lanford et al. (2003) compared the effects of using a “soft-belt” treadmill versus a traditional “hard-belt” treadmill on 27 active-duty soldiers (13 female, 14 male) who had lower-extremity musculoskeletal injuries. The subjects walked or ran at gradually increasing speeds until they experienced either the beginning of pain or an increase in pain from usual levels. The soft-belt treadmill allowed subjects to exercise at a 14.5% higher pain threshold speed, compared with the hard-belt treadmill. However, it was not certain whether the impact-forces speeds were significantly different (impact forces tend to increase as a function of running speed), as these were not measured. Thus, a practical safety measure for exercise professionals is to caution clients about running too fast on soft-belt treadmills, as their perception may not truly reflect the impact forces they are experiencing.
It is not the intent of this column to debate the mechanical parameter differences between barefoot and athletic-shoe (referred to as “shod”) running. Indeed, one of the goals of exercise professionals (in helping clients attain their individual goals) is to introduce various exercise stimuli that may enhance performance, motivate clients, develop a component of fitness or help minimize injuries. In this spirit, barefoot training may present an exciting new dimension for personal trainers to consider for some clients.
The 10 “Steps”
Hart and Smith (2008) propose a gradual approach to building a barefoot training program:
Step 1. Do not start the program with barefoot running. Begin by doing various activities of daily life without shoes; for example, gardening, walking to the mailbox and walking barefoot around the house.
Step 2. Introduce some movement activities on an even grass or indoor surface. Perhaps do some walking, jogging, calisthenics and games (e.g., volleyball or frisbee) at a park, in a grass field or on an indoor track (see Figure 1).
Step 3. Adopt a progressive overload approach, as you would with any exercise training program. Do multiple short sessions of barefoot training during a regular workout (e.g., 10 minutes at the beginning with another 10 minutes at the end), or do two to three 10-minute bouts throughout the day.
Step 4. For the first 2 weeks (or more), keep the total barefoot training time per session to no more than 30 minutes.
Step 5. Gradually increase the time, and/or combine the shorter sessions into one longer session.
Step 6. For variety, go with a combination of indoor and outdoor (grass and/or sand) movement activities.
Step 7. Progressively transition barefoot training to harder-surface (e.g., sidewalk) walking and movement activities. However, be very aware of rocks, glass and other harmful surface disturbances (e.g., holes, rough spots).
Step 8. Consider using a fitness facility, indoor location, mall or school gymnasium during inclement weather conditions, since cold environments can be a deterrent to barefoot training.
Step 9. Advise injured runners against doing any barefoot training until the symptoms of their injury have subsided. Caution clients with diabetes that barefoot running can be contraindicated for them because peripheral neuropathy (a common complication of diabetes) can lead to a loss of protective sensations in the feet (Warbuton 2001).
Step 10. Let clients know that several shoe companies and footwear manufacturers are now promoting new footwear products that purportedly simulate barefoot training. Some may prefer this option. Note that consistency is important with barefoot training, as data shows there is a loss of gained strength in the lower extremities when training stops.
Increasing the amount of time your clients run, walk and exercise barefoot may be surprisingly beneficial. Adding barefoot training to an exercise program is simple and natural. Perhaps the final word on it rightfully comes from the cover of Christopher McDougall’s book: “The secret to happiness is right at your feet, and … you, indeed all of us, were born to run.”