In his bestselling book Born to Run, Christopher McDougall argues that modern cushioned shoes are a major cause of injury, pointing instead to the thin sandals of the Tarahumara runners. So are these technological crutches actually hindering our health? In this guide, we explore whether barefoot treadmill training is a biomechanical breakthrough or a safety risk.
Is Running Barefoot on a Treadmill Good for You?
When you remove the thick foam of a traditional running shoe, your body immediately adapts its mechanics to protect itself from impact. According to a randomized crossover trial published in Sports Health (Gillinov et al., 2015), the most significant change occurs at the point of contact.
1. Strike Pattern Transformation
Traditional shoes encourage a Rearfoot Strike (RFS), or heel-striking, because the cushioned heel absorbs the initial shock. However, research shows that:
87% of runners wearing traditional shoes use a heel strike. The percentage for barefoot and socks is 67% and 40% separately, with the majority shifting to a Midfoot or Forefoot Strike.
2. Reduced Ground Contact Time
Barefoot training makes your stride more efficient by reducing the time your foot spends on the treadmill belt. The study found that ground contact time dropped from 265.9 ms in traditional shoes to 250.6 ms when barefoot. This lighter touch is often associated with a more spring-like, elastic running economy.
3. Lower Joint Torque
A systematic review in Medicine and Science in Sports and Exercise (Hollander et al., 2017) noted that habitual barefoot movers exhibit reduced ankle dorsiflexion at footstrike. In addition, compared with barefoot running, shod running elevates torque at the knee and hip joints, which is above the adaptations in stride cadence and stride length (Kerrigan et al., 2009).
4. The Vanishing Injury Phenomenon
One of the most striking findings comes from a survey of 509 runners published in the Journal of Sport and Health Science (Hryvniak et al., 2014). The study revealed that 69% of runners found their previous injuries—specifically those in the knee (46%), ankle (17%), hip (14%), and lower back (14%)—actually improved or disappeared after they began barefoot training.
5. Changes in Foot Morphology
Long-term barefoot activity literally reshapes your foundation. A systematic review (Hollander et al., 2017) found that habitually barefoot populations develop wider feet and a lower hallux angle (straighter big toes).
The Health & Injury Perspective
The shift in biomechanics isn't just a matter of physics; it has a direct impact on whether you stay on the treadmill or end up in the doctor's office. The data suggests that while barefoot training can be a cure for some, it introduces new demands on the body.
The Trade-off: New Injury Risks
While barefoot training may save your knees, it places a higher demand elsewhere.
Increased Calf/Achilles Load: Gillinov et al. (2015) concluded in the systematic review that barefoot and minimalist footwear increased Achilles tendon forces when compared with traditional shoes.
Stress Fractures: Gillinov et al. (2015) also warned that a sudden switch without gait retraining has been linked to metatarsal stress fractures, as the bones of the foot are not yet conditioned to the direct impact.
The Performance Paradox: Efficiency vs. Effort
It is a common misconception that barefoot means easier. Science suggests the opposite is true for your metabolism.
The 4% Energy Tax
According to ABC Science, researchers at the University of Colorado in Boulder found that barefoot runners used 4% more energy per step compared to running in lightweight, cushioned shoes [5]. This is because, without the mechanical cushioning of a shoe, your leg muscles must engage more intensely to dampen the impact of each stride.
Strength vs. Speed
While Gillinov et al. (2015) found that barefoot runners have a more efficient spring (shorter ground contact time), Eldred in ABC Science concluded that if your goal is purely to shave seconds off a race time, a lightweight shoe is still superior.
The Bottom Line
If your goal is to build long-term foot strength, correct your posture, or alleviate chronic knee pain, barefoot treadmill training is a biomechanical breakthrough. But if you are chasing a new speed record or a personal best, a lightweight shoe remains the more efficient choice.
To start safely, treat barefoot running as a skill session rather than a full workout. Listen to your body and let your feet reclaim their natural strength one step at a time.
References
[1] Gillinov SM, Laux S, Kuivila T, Hass D, Joy SM. Effect of Minimalist Footwear on Running Efficiency: A Randomized Crossover Trial. Sports Health. 2015;7(3):256-260. doi: 10.1177/1941738115571093.
[2] Hollander K, Heidt C, van der Zwaard BC, Braumann KM, Zech A. Long-term effects of habitual barefoot running and walking: A systematic review. Medicine and Science in Sports and Exercise. 2017;49(4):752-762. doi: 10.1249/MSS.0000000000001141.
[3] Kerrigan DC, Franz JR, Keenan GS, Dicharry J, Della Croce U, Wilder RP. The effect of running shoes on lower extremity joint torques. PM&R. 2009;1(12):1058-1063. doi: 10.1016/j.pmrj.2009.09.011.
[4] Hryvniak D, Dicharry J, Wilder R. Barefoot running survey: Evidence from the field. Journal of Sport and Health Science. 2014;3(2):131-136. doi: 10.1016/j.jshs.2014.03.008.
[5] https://www.abc.net.au/science/articles/2012/03/27/3464908.htm
