My son was living in the USA and upon his return, he brought me back one of these:-
comcorfitness.com/products/...
I acquired a couple of old tyres from a centre and some U brackets nuts and washers and with a bit of fiddle, all was good to go.
First impressions blimey I warmed up fast, five laps consisting of up the muddy driveway to the postbox and back approx 100 meters each time was I felt enough for a first go. I like it. I walked no attempt was made to run, I'm not sure if I could have TBH. I'm going to try to build on this it seems a great way to build up leg strength.