What do people think of them?

My missus brought one during lockdown and uses it all the time.

I tried it today for first time but hated it. Prefer normal running any day.

Do you get used to them?

"It feels much better than it ever did, much more sensitive." John Wayne Bobbit

Definitely, road running does your knees in. Treadmills, or better still exercise bikes are a better alternative!

I bought a treadmill in 2004 and love it. I haven't been on the road for over two years. In the lockdown, I was running 30 miles/week on it.
It is kinder on the ankles and knees as the deck flexes to take away the shock.
You can make up your own sessions.
When running on the road, it is easy to slow down at the end of a session. A treadmill will keep the same speed and 'forces' you to keep up.

Put the gradient up by 1 degree to counteract the help the treadmill gives.

It helps to watch TV as it does take your mind from the effort. Get a decent size set ( 40 inches ) and enjoy the sessions.

So hunting on bikes for ancient man was better ?

The three options you suggest are non-impact, but do not raise the heart-rate as much or use the same amount of energy. My rule of thumb is that you travel twice as far on a bike using half the calories compared to running.

Run for 1 hour uses 750 calories and travel 7 miles.
Cycle for 1 hour uses 375 calories and travel 14 miles.

I have been running and cycling for 30 years.

I also have a turbo-trainer.

This is pretty much it. You can potentially cycle everyday, and when you don’t you’ll get inner thigh cramps. But it’ll take hours of your time to burn calories and it doesn’t get you extremely fit like running.

I have also investigated injuries from running recently and there is the opinion that running can strengthen joints, cartilage and knees, rather than injuring them and wearing them out.

I think part of the problem with running is people do several things wrong.

Don’t stretch before and after. Hamstrings and calves are a must for me

Don’t listen to the body telling you to stop in that session if there’s a problem

Don’t build up speed and distance gradually or they run far too far than is necessary. So instead of retiring yourself from running days do slightly shorter distances.

Don’t wear shoes they’ve researched. Or they’re battered. Good shoes can’t be recommend enough. They last a long time and can make a difference from persevering or giving up, making the bad shoes a false economy anyway. Take it from me they make a huge difference and make it easier to ip your progress and break through barriers in regular intervals close together. Cheap shoes just make somewhere ache.

COYP

Yes I don’t stretch cold and sometimes don’t stretch at all. But post run stretch is so crucial stretch for me or I’ll alarming people when I groan in agony from hamstring cramps. Just above my Achilles is a problem area but when you know the signs you can manage the issues.

COYP