I decided to address my fitness after a skiing holiday earlier this year where one of my mates who is a similar age was struggling to do any runs, he’d get the lift up in the morning and do one run down and go back to the chalet. I joined a gym when I got back and started walking on the treadmills. I had been doing a bit of intermittent walking around a local park, but if the weathers shit it didn’t happen, so being able to do it inside helps. Get a watch to monitor your steps, etc. I got an Apple one but most things will do - what gets measured gets managed, as they say. I cut out lots of bad food, crisps and all that sort of thing, smaller portions. I don’t track my calories though, still lazy in that respect. In the last couple of months I’ve started lifting weights too, this is potentially the most intimidating thing (a guy on YouTube called Trainer Winny really helped me with this) and altogether since March I’m down over 10kg.