Some recommend 3 hours of walking or equivalent a day. 10,000 steps is an similar recommendation.
Hard for a desk job like most of us have. OTOH, as long as you're getting other exercise just standing instead of / as well as sitting might be enough if you're otherwise active.
Also hugely important for delaying bone density degradation, which starts declining after age 30, which is part of why the strength training should be reasonably heavy.
It doesn't help that when I do get outside that I tend to go "comfortably hard" and I'm in the no-man's-land somewhere between zone 2 and 5, not really capitalizing on the full benefits of either regime yet maximizing fatigue.
Like squatting with hundreds of pounds on your back is inherently unstable and forces you to have good balance, and moving your body under load is literally weighted stretching, which is one of the most effective ways of increasing your range of motion if your current range is insufficient for your needs.
- strength/resistance training: to build and keep muscles; one benefit of which is better stability at age and metabolic regulation.
- high intensity cardio/HIIT/zone 5/95+% max heart rate: to build VO2max, was also shown to reduce arterial plaque.
- normal cardio/zone 2/50-80% max HR: mitochondrial efficiency, fat burning?, endurance, memory (the current link)
Good frequencies seem to be 3x/week for normal cardio and strength, and 1x/week for HIIT.
A fourth could be stability/stretching/yoga-style exercises. I'm doing those on cardio days currently.
Not easy really. Though anything is better than nothing, so don't stress.