I have read that exercises like squats and bench press work a number of muscle groups. I really have limited time at the gym, and I'm trying to build an exercise routine that is as efficient as possible. What are the most efficient exercises that target the majority of muscle groups.
There are really only 2 movements: PUSH and PULL.
These two movements are then broken down into mostly 2 different planes: Vertical and Horizontal.
They look like this:
Vertical push: Overhead press
Vertical pull: Chinup/pullup
Horizontal push: Bench press or pushup
Horizontal pull: Rows
Vertical push: Squat
Vertical pull: Deadlift
If you do all these movements, you will no stone unturned. What is best (and most efficient) is to do antagonistic pairing (ie opposing movements in the same plane). If you are really short on time, do tri sets with a lower body exercise (squats or deadlifts) thrown in there as well.
I've got a routine I can finish within 5 minutes + time spent waiting for the squat rack.
I've usually done the following order, Squat > Overhead Press > Deadlift > Chin Ups, but other orders could work as well. The squat and deadlift by themselves already target the majority of muscles, the overhead press and chin ups have a lot of overlap but use the muscles differently (there's a good mix of pulling and pushing with those 4).
I do 1 work set of 5 reps, where 5 reps is usually the max I can handle at that weight (going up 5lbs per week initially for the press, 10lbs for the squat, 15lbs for the deadlift, and as many reps as possible in one set for chin ups), with each work set preceded by 1, and occasionally 2 warmup sets of 5 with ~40%-60% of my work weight.
I had quite good results with just that, and I don't think it gets more efficient than 5 minutes, once per week.
I'm a fan of the following progression(1), which is the simplest I've seen that hits all the major movements (press, pull, squat, hinge). The beauty of the workout is that each exercise warms up the next one. It goes like so, adding weight to the bar both between and within each step:
Between 2 and 3, you could add a few squats from a rack if your squat is much stronger than your clean.
The last time I did this, I power clean and pressed 45 pounds as a warm-up, then 95, then 120 or so. Then I power clean and front squatted 145 or so, then 200 or so. Then I deadlifted in the 300s before doing three sets of chin-ups.
I get the "major movements" from an amalgam of the work of Mark Rippetoe and Dan John, the latter of whom might recommend adding a farmer's walk finisher to the end of the workout. (He sees carries as another fundamental movement.) I figure that squatting, deadlifting, pressing, and chinning covers all the basics of lifting. The rest of human movement (or "targeting" other "muscle groups") can come from sports or running.
In terms of muscles worked, which I think is a red herring in this endeavor, you're hitting everything. Squats work almost everything in your body, as do deadlifts, and anything they miss, the presses and chins should get. As far as I know, these exercises require the broadest swath of our body.
1 - On second thought, this may be more explicitly cribbed from Dan John's book with Pavel than I initially recalled. Will have to check.