It’s honestly not terribly difficult to become a super crazy awesome exerciser. At it’s simplest, a plan would look like this:
Deadlift and Squat heavy (together) one day per week. (Or replace the Deadlift with the Clean.)
Bench Press and Military Press heavy (together) one day per week. (Or replace the Military Press with the Snatch/Push Press/Jerk.)
One upper body volume day, focusing on chest, back, shoulders, and arms, including isolation work.
One lower body volume day, focusing on glutes, hamstrings, low back, quads, and calves, including isolation work.
One day per week to mess around with light new movements/sport specific motions, or if you don’t care about that stuff, a third volume day to focus on whatever you like. (Calisthenics, flexibility, yoga, gymnastics, strongman lifts, olympic lifts, sport game of your choice, grip training, arm wrestling, etc.)
Leaving two days per week for rest.
2-4 cardio workouts per week, alongside your other workouts. These should generally last no more than 30-45 minutes at a time, and should be balanced with the intensity of the lifting so that you aren’t doing high intensity running on the same day you’re doing high intensity lifting. Some of these workouts can be intervals, but intervals should be integrated even more carefully. Do light cardio on recovery days if you want. If you prefer a cardio heavy sport, consider skipping heavy or volume days (but not both) to provide more time/recovery to focus on cardio.
Focus on increasing volume in a sustainable way over time. This means more sets, more reps, more weight, and ultimately more time spent in the gym. Hit a point at which you're spending too much time in the gym? That's the limit of your abilities.
Want to lose weight? Eat more protein and eat less overall. Want to gain muscle? Eat more protein and eat more overall. Want to simply lean out? Eat more protein and eat roughly the same overall.
Now rinse and repeat every week for ten years.
Of course, it’s not as simple as that.
Adherence to any exercise program is about psychology, meaning that the hard part in this program doesn’t have anything to do with the programming itself, it has to do with the ten years part. The vast majority of people won’t stick it out. They’ll do it for a week or two and then they’ll drop off. Giving them this program won’t do anything for them.
Sometimes it’s not about the program. There are millions of free programs out there, and yet we aren’t all suddenly Arnold Schwarzenegger (at least last I checked, unless stuff has changed a lot since I left the states). Every one of these programs can work, but nothing works if you don’t put the effort in.
Am I saying that everyone should either be all-in or all-out? No. But if you really want to do well for yourself as an exerciser, here’s what you need to do:
Build up slowly, and don’t jump into too much too quick.
Focus on sustainability. Don’t repeat anything that you find discouraging you from returning to the gym.
Build a set of habits around going to the gym, and reinforce them with small rewards.
Find a source of motivation. That can be competition, a trainer, a good gym, a workout buddy, or lots of mirror selfies shared to instagram #fitfam #yolo #fitness #muscles #workout #grind #pump #beast #gains.
Don’t give up.
The psychological factors are going to be a lot harder to reign in than your training, I can assure you. But if you really want to become the sexy strong beast you’ve always wanted to be, you’re going to have to be honest with yourself, put in the mental effort, and work at it. Hell, you could ignore the above program entirely, and as long as you do anything for ten years straight, you’re probably gonna get pretty good at it. Will you turn into Arnold or Froning? Probably not, but there's always a possibility. Just pick literally anything other than sitting, and you’re good.