For Runners, Soft Surface Can Be Just as Hard on the Body

Exercise researchers say there are no rigorous gold-standard studies in which large numbers of people were assigned to run on soft or hard surfaces, then followed to compare injury rates.

There’s a good reason for that, said Stuart J. Warden, director of the Indiana Center for Translational Musculoskeletal Research at Indiana University. It’s too hard to recruit large numbers of people willing to be randomly assigned to one surface or another for their runs.

“I think the reason people haven’t answered that question is that it is not an easy question to answer,” Dr. Warden said.