These two questions are actually related, since for most people, access to serious weights or the kind of gym equipment they might previously have been familiar with is severely limited.
As a result, many are either reaching under their beds or into the back of their wardrobes for discarded lightweights, last used years ago or are turning to more cardio’ type exercise (running!).
Both are good options, though many people are averse to tripping over dumbells in their lounge.
For myself, I am a particular fan of running, particularly in the open air, as running is a great exercise for building cardiovascular strength and I find it a wonderful way to settle the mind.
My specific advice right now would be to build a routine on the foundation of a warm-up/cardio’ exercise such as running or cycling and to add onto this a simple whole-body routine that works each body part, using minimal equipment or body resistance: Press-ups, squats, resistance band arm exercises – all of these will keep your body taunt and ready for when the gyms re-open.
As for when to exercise, my advice is to do so as regularly as possible, since the physical demand of exercising as above will be lighter and require less recovery as opposed to exercising at a gym.
So feel fine about working out for shorter periods than you might be used to if you are a gym regular. Exercising each day, for example, for around 30 minutes (as little as 20 minutes) will have the desired outcome.
The important principles are to put in place a structure for exercising, to maintain your chosen programme and to then exercise enough to maintain your body.
So, get out, enjoy the sunshine that is available at this time of year and keep the fitness vibe going.