Don’t wear a fitness tracker, plan your route so there are fewer junctions and remember you won’t get up any speed wearing tweed
If you have any sort of journey to work at the moment, it’s likely you will have thought about a bicycle commute. And likely, if you have, you’ve concluded that it’s a little bit longer than you’d prefer (otherwise you’d have been doing it all along) and that you need to dangle some reward in front of yourself, such as, “It’ll make me really fit.” (Meanwhile, if you’re working from home for lockdown, you may be eyeing up your bike as a means of escaping reality, and getting fit at the same time.)
The truth is, cycling to work is in a different league from club cycling. It may cheer you up, count as moderate exercise and be better than nothing, but it won’t hugely boost your fitness levels for the following three reasons: you go slowly so you don’t get sweaty and ruin your work clothes; you endlessly stop and start, because of traffic lights; you only use your leg muscles, rather than your core or arms (and you only use half your leg muscles at that).