Here's my Minimum Effective Dose system for the perfect body.
This system is designed to give you the best possible body with the least possible resource expenditure - the main resource in this case being time. This is NOT supposed to be some expert treatise on the scientifically most impactful way to get the biggest muscles and the highest VO2 max. There is an infinite amount of content on this on the web, complete with drug enhancements and nutritional supplements. This is a method for really busy people (read productive people with a rich and varied life), who want a great body without being training obsessives.
In a nutshell, this will mean two 30 minute resistance sessions, and two-three 30 minute cardio sessions, per week.
So, before I outline the method, here are the guiding principles on which it is built. It is important to read and understand these because you will want to adjust the system for your own needs and constraints, and adhering to these principles will help you do this.
Food better than exercise - It is much easier and more impactful to control what you eat than exercise it away. Unless you're a professional athlete, no matter what you do, it will be hard to exercise away regular beer and burgers. Not putting a pack of biscuits in your trolly is way easier than a 45 minute HIIT session. You win the battle in the supermarket, not the gym.
Weights are important - Resistance training increases your metabolism and should be part of your routine.
One set - Every exercise is reduced to one "superset" where you compress the muscle tearing you'd normally get in three sets in one.
Opposing body parts - To eliminate rest (and time) between sets.
Minimum frequency - Twice a week, 1 set per body part.
Bodyweight - No need to be in the gym if you can't.
Slow is heavy - Where you can't adjust weights, adjust speed.
Form is challenge - Getting the right form multiplies the benefit of the exercise.
Form before weight - Never sacrifice form for higher weight; DO sacrifice weight for better form.
To get good muscle growth you need to do the exercise such that you achieve muscle tearing; the muscles then repair stronger. The "cheapest" way to do this is supersets. This means that, for a given exercise, you aim for one set of 10-12 reps. Start with the heaviest possible weight - this means a weight heavy enough such that you can manage 3-4 reps max. You then immediately move to a slightly lower weight, you'll probably manage 2-4 reps here. Carry on like this until you're in the 10-12 reps zone, ideally to exhaustion (this may mean 13 or 14 reps in total, that's fine). It can be with some exercises you literally manage 1-2 reps at each weight, and end up on a much lighter weight than when you started. This is great. With this method, you will have achieved multiple muscle tearing events during one set, thereby compressing 3 sets' worth of training into one. You will find that with this method, you are in pain virtually the entire time as you go through the set - unlike other systems, where the pain comes at the end of the set. Again, this is the constant tearing, and is a good thing - it is the other side of the coin of being efficient. Overall, you'll be in pain most of the time that you're training.
As you perform the exercises, always follow two principles. First, it's one count up, four count down. So ie, if you're bench pressing, push the bar up in one smooth, controlled push higher; then lower it in a slow, controlled four count down. This is how you should perform every exercise. It will seem weird at first, and you'll be tempted not to do this. But it is just a habit, and you are ruining your effectiveness if you cheat. The four count down allows you to achieve what is known as "negatives" - ie you are training your muscle on the way down as well as up. This doubles your impact per set and is where the extra burn and efficiency comes from.
As a generalisation, when you don't have access to multiple weights for an exercise and don't want to do 50 reps to exhaustion, just slow things down. Turning the 1 count / 4 count into a 2 count/8 count; or 4/4; or 4/8; will achieve the same thing.
Second, get the form right. Again, you will be tempted to compromise form to lift a heavier weight. But this simply means you're going too heavy. Or, put another way, you can't lift that heavy (as evidenced by you having to compromise your form). Compromising form is a way of diluting the effect on your muscle, so in a way you are going heavier and lighter at the same time, causing injury for no benefit. Again, this is a habit - get used to being a form nazi.
Employing this method, you'll want to design the routine such that you're exercising opposite body parts after one another - this way you won't need to rest between sets. You will see how I do this below. If you can hit a gym and use the weight machines to have a fine adjustment of the weights throughout the set, that's great. Personally, I don't bother - for one I can't be bothered to get to the gym; for another, it is much more efficient to do this at home time-wise; for a third, I like the challenge of bodyweight training. You'll see my variations if you don't have a gym available below.
Here is my current routine. I articulate it not because it is the best thing out there for anyone - or even just for me - it is more to demonstrate how to apply the principles. My routine has evolved and continues to evolve all the time - it is never really static, but the principles are. Don't get hung up on the individual exercises, rather you should pick your own for convenience and whatever you like/think works. Again, what's important here is the why's more than the what's.
Lateral raise (shoulders) - This is the exercise where you look like you're trying to fly with weights in your hand. Form is really tricky on these so focus.
Pull-ups - I just do some slow pull-ups, arms a bit wide. It may well be you can only manage one or two to begin with. That's fine. Eventually do 3, then 4, etc. I love pull-ups, I think it's the best single exercise you can do. I have no evidence of this other than my body and how I feel. The gym variant is lateral pul