While we feel specially proud when having a good run and think that it helps our legs become stronger, some experts say that might not always be the case.
If you're an average recreational runner, you probably take 150 to 170 steps per minute. So basically, your feet get to hit the ground about 5000 times when you feel like doing just a "light", half-hour run.
“Every time your foot hits the ground, your body absorbs the impact,” says John Mercer at the University of Nevada, Las Vegas.
With the use of high-speed cameras, leg sensors and force-sensing plates, Delphine Chadefaux at Aix-Marseille University in France and colleagues was able to look closely on how such popular cardio exercise affect our bodies. They specifically studied on 10 recreational runners' motion, acceleration, muscle activity and the force of hitting the ground when running with both their shoes on and barefoot. Each was also asked to run at two different speeds.
With this, researchers found that as expected, our foot absorbs the most impact when we run and decreases as it travels upwards through the shinbone and knee. Now don't even think about running barefoot for findings show that doing so produced about four times the shock (in our feet) than when running with shoes.
And for both groups, researchers also found that the "vibrations" caused by the impact almost entirely dispersed when they reach the hip.
"Oh well, I'll just stick with wearing my shoes then," you might think. However, that's not entirely the point. Regardless when using (today's) running shoes or not, our feet still get most of the shock.
But thanks to this research, we might (hopefully) soon understand better on how to reduce such shock in the lower part of our body (legs up to our feet) and pinpoint ways to prevent common injuries like stress fractures and joint problems.
“If you have too many impacts and the bone does not have a chance to recover, that can lead to a stress fracture or some other issue,” says Mercer.
So here's to better shoes (?) or a more effective way of running!