If you’ve ever paid close attention to runners, or are one yourself, you might have noticed most strike the ground with their heels first, rolling on to their toes as the next stride carries them forward. It’s common enough that people tend not to question whether this is the best way to run. After all, one study set the number of rearfoot runners at 95%, while previous studies only dipped as low as 75%.

It’s easy to view this as evidence that people are rearfoot runners by nature. Questions have been raised about this; while a 2013 study found that 72% of a small subset of Kenyans that ran barefoot were rearfoot runners, the book Born to Run discusses the Tarahumara tribe in Mexico and their capacity to cover incredible distances with a toe running technique. The broad observation of barefoot runners as forefoot strikers led to the rise of toe shoes among runners and other athletes; however, it’s worth noting that the popularity of those shoes has faded.

Natural stride aside, what is the effect of where the foot strikes on distance running? Most runners are concerned about one, or both, of two things: speed and safety.

Speed

For a distance runner, speed is something of a misnomer. Sprinters need speed, and train their bodies to maximize power to achieve it. Distance runners seeking the best possible times need efficiency, and thus train for endurance. A person whose form deteriorates due to fatigue cannot put up the best time their body is potentially capable of producing. Only once the body can be efficient over the entire distance can extra power make a difference.

A study at UMass sought to determine if rearfoot or forefront striking is more efficient. Sixteen runners of each type were brought in and tested with their normal running styles. The groups were found to be equally efficient. However, when they were asked to switch to the opposite style (forefoot runners going rearfoot and vice versa), the forefoot runners adapted much more easily. In fact, twelve of the sixteen forefoot runners were found to be more efficient when running rearfoot. This would suggest an advantage for rearfoot running.

On the other hand, a 2007 study showed that elite runners tend towards forefoot and midfoot striking. These may not be mutually exclusive pieces of data. It’s possible rearfoot running is more generally efficient, but for people who have built up sufficient endurance to be able to add speed training to their distance running, forefoot running may offer better speed advantages.

Safety

The other issue, probably of more concern to amateur runners, is safety. After all, you want to perform your best, but you can’t do that if you’re injured. There is less of a question here, as far as science can tell: Rearfoot running has either an equal or increased chance of injury compared to forefoot running.

Two studies indicate forefoot running results in fewer repetitive stress or knee injuries. Others, however, show no appreciable difference. One article noted that the first of those two studies focused on a non-representative group of runners (college athletes), and that when separated by injury severity and gender, only the female runners had a significant difference between rearfoot and forefoot strikers.

What’s Best For You

So what’s the best running style? The answer may well be that the way you run is correct, because your body is used to it. Efficiency appears to depend on the person, and injury risk may be highest for people attempting to switch styles rather than being attached to one in particular. New runners may find it less impactful on the knees to run on their toes, but in the end, personal comfort should dictate your style. Do what your body asks and it will serve you best.

Sources:

http://sprunig.net/wp-content/uploads/Is-the-rearfoot-pattern-the-most-frequently-foot-strike-pattern-among-recreational-shod-distance-runners_2015.pdf

https://www.runnersworld.com/newswire/study-rearfoot-forefoot-strike-equally-efficient

https://www.runnersworld.com/newswire/new-study-reaches-different-conclusion-on-kenyan-foot-strikes

http://www.lbgmedical.com/media/journals/Running/Knee-Adduction-FFS.pdf

https://www.ncbi.nlm.nih.gov/pubmed/17685722

https://www.ncbi.nlm.nih.gov/pubmed/23748735

http://jap.physiology.org/content/early/2013/05/13/japplphysiol.01437.2012.full.pdf+html

http://www.sciencedirect.com/science/article/pii/S2095254617300285