The Core Four Movements
At the most basic level, resistance training can be broken down into four types of movements, they are; Squat, Hinge, Push and Pull. Let's take a look at each one
Squat (pic of me at top and bottom of position, front and side view)
The quadriceps (muscles on the front of your thigh) and glutes (butt muscles) are the primary movers for this. Squatting is something most of us do all day without even thinking about it. Every time you sit down, you're doing a squat. When talking about squats from a perspective of exercise, it's lowering the hips and butt down, then standing back up, easy enough on paper right? Unfortunately, most people in the western world have no clue how to squat properly. Unbeknownst to you, you were probably an excellent squatter as a toddler. When a toddler picks something up from the ground, they drop in to a deep squat that most lifters would be jealous of. You did it before and you can do it again.
Hinge (pics again)
Here again the glutes are used, as well the hamstrings (muscles on the back of your thigh) and your lower back are doing most of the work. The hinge occurs when you bend at the waist, common hinge exercises include the deadlift and kettlebell swing. You also hinge whenever you bend over to pick something up off the floor. This can be troublesome when the object you're picking up is too heavy and your lower back isn't strong enough to handle the load, thus leading to injury. Lower back pain and injury are an incredibly common in our society, but a healthy and strong back can prevent and correct this problem. Learning to properly execute hinge exercises can go a long way in preventing pain and discomfort as you age.
The main pushing muscles include the pectorals (chest), triceps (back of the arm) and deltoids (shoulders). Classic examples of a push movement include the bench press and push up. Pushing exercises are very accessible and easy to perform without any equipment.
Muscles used include the Latissimus Dorsi (big muscle running down your side), rhomboids (mid back muscles) and biceps. Common exercises are pull ups and rows. You may not be as familiar with these for a couple of reasons. Pull ups are much harder than a push up, also pull ups require a bar to pull up on. Also, you need a bar or weights to perform any type of row as well.