2021 - 52 weeks of doing something different

Could you explain "daily planking" please?

Good for the back and core strength but you don't need to run around and get hot and bothered!! 
https://www.theguardian.com/lifeandstyle...ona-vertue

^^^ not on one leg I hope

Yes, and one arm if you get really strong ...

Apparently it is just a fad, but I did it for about three months last year, building up a little each day, and it did make a difference to my general strength and also I seemed to be less insomniac, too, so good for my mental health. I then had an RA flare and was very fatigued with too much pain in my elbows and shoulders so stopped  I think I would have felt better overall if I'd kept at it, even if for a reduced amount of time.