Lockdown is very unhealthy for me. I did a trail half marathon at the end of Feb last year... I did C25k in August...
I lose the incidental fitness of briskly walking the school run. Prior to March, I'd walk up and down our stretch of road about 16 times a week for school/ extra curriculars and it does add up.
I lose my fitness classes and I just don't manage doing them on zoom. The environment is uncomfortable, it's not genuine company. Space, planning the time.
The DCs are around (plus added mess) they need constant support to do any home learning. In the spring I could head off for a quiet trail run after that, but now there is more rigid home learning so I don't have the daylight and I'm stuck with short, tedious, jarring, undulating pavement runs through my neighbourhood.
I kept the running up Mar-May but without access to my osteopath the niggles built up and I was struggling by June and went out about 3 times.
My running normally ebbs and flows around races, but there's enough other activity and classes in there for that to be no great issue.
Lockdown #2 was OK because the DCs were in school and the only difference it made compared to the previous month was losing organised sport.
Last time I went for a trail run, the ground was really struggling from increased food fall pulverising it into mud. So it a choice of pavement pounding, mud swamps or dodging formation pedestrians clogging up the parks.