Running with a bounce is also known as vertical oscillation whereby studies show that too much of the wrong bounce, which is influenced by running style, can heavily impact running economy.
Heel strike runners are more prone to running with greater vertical oscillation as compared with forefoot strike runners. Both types of running styles involve bouncing, however bare in mind that if you run with a heel strike you will bounce more whereby the more vertical oscillation during running, the more energy wasted. For example (Slawinski and Billat, 2004) discovered that runners who ran with greater bounce were less mechanically efficient because the legs work harder to push the upper body higher up off the ground, thereby performing more work against gravity.
Running with a Bounce – Is It Bad?
Newer studies, suggests that bouncing while running is not as bad as once thought in that the minor bounce associated with forefoot running saves more energy as compared with the bounce that heel strike running creates.
Research has identified 2 types of bouncing gaits in running: elastic bounce and muscular bounce (Legramadni et al. 2013), whereby an elastic bounce is associated with a forefoot strike and a muscular bounce is associated with a heel strike.
Some reports have found that an elastic bounce may provide greater energetic efficiency over a muscular bounce in running (Alexander, 2002), suggesting that forefoot running may save more energy than heel strike running.
Elastic Bouncing is Better
An elastic bounce is powered by the elastic contributions of the Achilles tendon.
In a forefoot strike, elastic energy storage and recovery is greater as a function of the relative length changes in the Achilles tendon per step (Cavagna et al. 1977)
- studies show elastic contributions in running result in savings in energy costs by 20%-25% (Cavagna et al. 1977)
How Muscular Bouncing Drains Energy
The leg muscles, and less of the Achilles tendon, contribute to a muscular bounce.
In heel striking, the muscular bounce is initiated by the propulsive phase, shortly after heel strike (Gill and O’Connor, 2003).
Heel strikers often run with an exaggerated pendulum-like gait, resulting in lunging strides where the body is propelled using the forefoot. The lunge-like strides in heel striking places significantly more demands on the musculature of the lower legs and feet.
- the braking phase in heel striking accounts for the lack of elastic contributions of the lower leg, therefore reduces elastic bouncing when running
- one study reported that the peak impact force generated at heel strike was a relevant factor in impeding elastic bouncing (Cavagna et al. 1964, Pohl et al. 2009).
The Take Home Message
Bouncing when running, if influenced at the level of the tendon (elastic bounce), may enhance running economy. Since elastic bouncing when running is associated with a forefoot strike, forefoot strike running may be more efficient than heel striking.
And lastly, experts are quick to point out that in heel striking, the peak impact force that hinders elasticity effectiveness of the leg (Milner, 2006), remains firmly in the realm of running related injuries.
Run Forefoot Because You are Faster than You Think!
More on Why You Should Not Heel Strike:
Shin Splints – Find out why heel strike runners are more prone to shin splints than forefoot runners.
Runners Knee – Learn how heel strike running blasts the knee with higher impact forces than forefoot running
Lower Back Pain – Heel strike-related impact implicated in chronic lower back pain
Soft Tissue Vibration and Injury – Discover how the heel strike-transient overloads soft tissue compartments, sending them into a fatigue state.
Legramadni, MA., Schepens, B., and Cavagna, GA. Running humans attain optimal elastic bounce in their teens. Sci Rep, 2013; 3: 1310.
Alexander, RM. Tendon elasticity and muscle function. Comp Biomech Physiol A Mol Integr Physiol, 2002; 133(4):1001-11.
Cavagna, GA., Pollock, ML., and Landa, J. A biomechanical comparison of elite and good distance runners. Annauls of the New York Academy of Science, 1977; 301: 328-345.
Gill, HS and O’Connor, JJ. Heel strike and the pathomechanics of osteoarthritis: a pilot gait study. J Biomech, 2003; 36(11):1625-31.
Cavagna, GA., Saibene, FP., and Margari, R. Mechanical work in running. J Appl Physiol, 1964; 19(2): 249-256.
Pohl, MB., Hamill, J., and Davis, IS. Biomechanical and anatomic factors associated with a history of plantar fascitis in female runners. Clin J Sport Med, 2009; 19(5):372-6.
Milner et al. Biomechanical factors associated with tibial stress fracture in female runners. Med Sci Sports Exerc, 2006; 38(2):323-8.
Slawinski JS, Billat VL. Difference in mechanical and energy cost between highly, well, and nontrained runners. Med Sci Sports Exerc. 2004;36:1440–6.
BSc Neurobiology; MSc Biomechanics candidate, ultra minimalist runner & founder of RunForefoot. I was a heel striker, always injured. I was inspired by the great Tirunesh Dibaba to try forefoot running. Now, I'm injury free. This is why I launched Run Forefoot, to advocate the health & performance benefits of forefoot running and to raise awareness on the dangers of heel striking, because the world needs to know.