It took me a bit to choose this answer. It came down to squats or deadlifts. At the end of it all, I believe squats are the king of all exercises.
Squats are like Jon Snow. Deadlifts are like Daenerys. Individually, they both have their pro’s and con’s but together they reap the full benefits of glory (gains). There is however, a power struggle and deadlifts may tax the system more, and thus need more recovery time (much like Dany, needs to cool off after a dragon breathing power struggle), the squats prevail.
What the Hell Did You Just Say?
Ok let me get back to reality. I was originally going to choose deadlifts as the king. It incorporates more upper body, and forearm strength, whereas the squat is predominantly lower body. You even get the full posterior chain worked on deadlifts. But that comes at a price. It works more lower back, which is also used in a lot more exercises. If not programmed correctly, and too much low back oriented volume is added on, you can severely hinder recovery.
Strength and Form
The beauty of the squat is that it doesn’t let you get away with much. You form needs to be on POINT otherwise you suffer big consequences. It also works pretty much all muscles of the leg (quads, hamstrings, glutes) through a fuller range of motion. If you are tight on time, squats allow you to hit the most amount in the smallest time frame. Don’t forget, you are still isometrically contracting your back and shoulders.
An exercise is only as good as the technique. I’ve seen way too many people with shotty technique, “muscle” their way through a super heavy deadlift. That’s bad news bears. A proper squat forces you to stay upright throughout the full range. You can’t muscle through it. You either complete the lift, or you have to bail. Squats also stimulate so many larger lower body muscle groups that systematically, they help the upper body grow as well. How many exercises can say that?
Mobility
Being able to squat to the ground properly, means your range of motion in the hips, ankles, and knees are golden. Most people, especially as they age, get tight in their low back, achilles, or simply have bad knees. They lose their range of motion, and usually end up injured due to other muscles taking up the brunt of the weight when they shouldn’t.
If you did nothing else but spend 30-45 minutes in the gym working on proper form with lighter weight, you’d be doing your future self a huge service and providing prehab to all the muscles involved. Bench press isn’t going to do that.
Mindset
Ever maxed out on a squat? It like nothing else. The feeling of knowing hundreds of pounds are literally on your back and it’s up to no one else but YOU to get that weight back up otherwise you collapse. If that isn’t an excellent test for mental toughness and discipline I don’t know what is. Hell, do lighter weight for more reps and you’ll still be contemplating your life choices!
At the end of the day, we only have one body. We need to take damn good care of it, and allow it to be used the way it was designed for as long as we can. Look at any baby squatting and you’ll see that requires full depth, proper form, and the mobility to be comfortable in that space.