[TulliusCicero]

It seems like the distinguishing factor is intensity, so it's likely you could substitute in some other higher-intensity workout that may be easier on the joints, like swimming.

[spudlyo]

An elliptical trainer also works well for getting the heart pumping without hurting the joints.

[kazinator]

But "getting the heart pumping" isn't the same as improving "age-related deterioration in walking economy".

[soperj]

For my money, skating is easily the easiest on joints for high intensity exercise.

[ams6110]

Falling on the ice is pretty rough though. If you're starting out, wear hockey pants and elbow pads. And maybe a helmet.

[soperj]

Better than falling on cement, you slide.