Many people believe that they should run on soft surfaces, such as grass, to lower the forces on their joints and therefore make running more comfortable and lengthen their running career. However, this isn’t entirely backed up by the research. Some studies have actually shown higher joint forces when running on grass and other softer surfaces, and lower joint forces when running on stiff surfaces such as concrete.

Which begs the question, why? When you run on a soft surface, your body automatically compensates and becomes more stiff which reduces your leg spring. Stiff running has been shown to increase ground reaction forces into joints. And when you run on a firm surface, your leg spring softens and absorbs the ground reaction forces, ultimately lowering your joint forces.

So what surface should you run on? Really, it depends on your situation. If you’re training for a road marathon, then training on the roads is ideal. If you’re training for trail runs, then it’s best to do a fair portion of your training on the trails. When returning from injury, I get my patients to recommence running on a dry, well lit, flat and firm surface. But long term, studies suggest that running on a firm surface will be better for your joints.

And above all else, technique and training load management are the cornerstones of having a long term, successful running career. If you’re keen to learn more or have your running technique assessed, book in for an appointment or running analysis with one of our running physios.

Nick Rees
Physiotherapist