Not really an expert here but happy to share my path. My current goal is to maintain minimum flexibility, do some resistance training and keep some aerobic fitn

Not really an expert here but happy to share my path. My current goal is to maintain minimum flexibility, do some resistance training and keep some aerobic fitness. If you have very little exercise from recent years, I really recommend finding a local personal trainer, explain you want a bare minimum personal program and start from there. Once you know what your body can do under supervision you can think about how to develop routines that last your life. Personally I bought some courses from GMB fitness for mobility and for some kettlebell stuff read the book ”Simple&Sinister” whose basic program I did for a year, and then started doing ”The quick and the dead” program from the same author. Now - the books are a bit weird and the motivational narration may be offputting but the exercises seem legit and effective. I don’t know if any of the above is usefull at all for anyone else. But the basic science sort of goes you need some basic aerobic exercise and some resistance training. Free weights like kettlebell seem to offer best bang for buck since the basic exercises actually train a lot of the muscles at the same time. The ”lets isolate the muscle groups and pinpoint these exercises” regimen might have it’s use but’s imho it’s sort overcomplicating the basic equation if you really are not training for anything particular and have no handicaps from injuries. I understand the deadlift is a super effective and simple technique but I hate going to gym and don’t have space for anyhting else except kettlebell. Like Scott Hanselman tipped - plan a routine that gives you least amount of opportunities for excuses.