TrueForm reimagined their popular commercial-grade manual treadmill for at-home use, building a sturdy machine with a shock-absorbing belt that will help you pick up the pace and go the distance.

These were the curved, self-powered treadmills I had heard about—models include the Woodway Curve Trainer, Trueform Runner, and Technogym SkillMill. I climbed aboard. Because this type of ...