80% of the things work for 80% of the people 80% of the time.
What those slices are depend on who the person is and what the goal is.
If you want to get better at any sport, do it frequently and under professional supervision.
If you want to lose weight, eat a little less, aim for 3 hours of aerobic (breathless and sweaty) activity with a few bouts of high intensity interval training a week.
If you want to improve general health, longevity and decrease your global risk of nasty illnesses, drink less alcohol, drink more water, eat a balanced diet, keep your weight down, don’t smoke and move regularly.
The problem is, for many people, simple is boring and they are convinced there is a short cut, an easy solution that limits the hard work involved in positive changes.
The bad news is there isn’t.
The good news is that hard work, consistency and simplicity are the 80% gainers, the actions that pay back.
The rest, until you are at elite levels, is propaganda and ways of making money move from your purse to theirs.
Define your goal, apply yourself and achieve.