If you are pressed on time, just read this: unwinding is enough, goals are just for those who want to reach them (know yourself) and not necessarily better. To be healthy, various forms av light cardio and mobility are enough. If you do only weight lifting you are probably doing too little cardio, but just adding a few minutes of high intensity intervals a week would be enough. If you want more out of training, it's just that - you wanting more - but not necessary or much healthier, albeit probably a little better, at least for old people.
Now on to the long answer:
To me exercise comes down to choice, just as it does with success and happiness. Well, I put it as an either-or choice; you could almost just as well establish a tolerable or with time unavoidable or even enjoyable habit that effortlessly leads to success - like my pre-teen round-the-clock video gaming habit (see the same post about success and happiness).
Regarding exercise you might want to choose betweeen the following goals or proceed with one after the other in this order:
4. All of the above
I think you should focus on nr 1 first; aim for a long and healthy life. Embed your training as much as possible in your daily life, for the most impact with the least effort: The MILE approach could look like this, in this order:
If you do nothing, walk. If you walk, add mobility. Then stand at the office and take the stairs when you can
THE MILE APPROACH to get the most mileage out of your body
- walk (easy, doesn't get you sweaty, breaks your sitting periods, makes you smarter, trigger insights. Walk for 5 minutes or 5 hours; the longer the better as lonmg as you have time to eat and sleep, but anything is better than nothing)
- simple mobility exercises (couch stretch, squat, shoulders, glutes/ass and spine/torso, all of these postpones the age when you walk like an old man and undoes the damage from sitting all day. They are easy enough to do in front of the TV, the office chair or by sneaking away to the conference room for 5 minutes. Start with once a month and then aim for 5 minutes a week and finally 5 minutes every second day or even every day.)
- stand (at the office, if you can, at least an hour a day. Make sure you never sit more than 60 minutes at a time without a couple of minutes' break for copying, getting coffee, lunch or whatever)
- take the stairs (aim for a pulse of >120 bpm a couple of minutes every day)
- cardio (doctors recommend 30 minutes of sweaty exercise every second day so why not go for an easy jog 4-6 kilometres, 2-4 miles)
- HIIT (the fastest way of getting in good enough shape; short bouts of maximum effort. A couple of minute a week are enough but I think you should aim for more. Aim for 16 one-minute intervals three times a week. It can be running, cycling, stairmaster, treadmill, swimming, cross-fit exercises...)
Then, if you are done and happy with nr 1 and actually want strength, power and functional muscles that help you fight off bad guys, do sports or support you in everyday tasks like moving furniture around, proceed with step 2.
Nota bene that there is nothing inherently better or more desireable in moving on to step 2 from step 1. It is just a matter of taste. You don't need extra strong muscles to be happy or successful or live a long and healthy life, but it might be fun, might boost your self-confidence, might even help in reaching other goals. And some strength is good for you and your bone density as you grow older. The regime to get there also means acquiring a new skill set and discipline than the MILE approach.
To build a strong and functional body you should do heavy compound exercises with a free bar. You could also join a free climbing group or start with gymnastics, but most people find it easier to just go to the local gym. I have described how I do it here. In order of importance:
- squat - squat deep for full benefits, hits almost the entire body, including legs, calves, grip, abs, back, arms
- deadlift - watch your back, but if you keep good form this mother of all exercises builds legs, upper and lower back, grip strength and abs, as well as good habits when lifting stuff off the floor...and better proprioception
- pullups - biceps, grip, lats, upper back
- overhead press - shoulders, triceps, abs
- bench press - the least important of the big lifts; it builds pecs, shoulders and triceps
- various - complement the big five with cleans and box jumps, e.g. You could also add some cross-fit exercises like burpees but with strict technique rather than as many with poor form as possible.
And for the final exam, if you are strong and agile but want to look bigger and better, more like a bodybuilder than just the average handy man: Aesthetics & Beauty:
- alternate between trying to build as much strength as possible and building as much muscle volume as possible.
- Go as heavy as possible for 1-3 months, starting with e.g. 10 reps per set and gradually going down to heavy 3's, 2's and even 1RM's.
- Then do 1-3 months with focus on high reps (10-15 per set), metabolic stress, short set rests, long Time under Tension. Include some negative reps too, i.e., slow eccentric phase.
- alternate bulking periods with muscle definition periods
- focus more on gaining weight and strength some periods
- focus on cutting down the fat and making your muscles visible in other periods
- Be reasonable; a handful of kilograms or 10-15 pounds is enough variation
- Extremes are bad for you in the long run
- And if you are a competitive bodybuilder, what are you doing here?!