David
Deadlifts > Everything
Updated: Feb 14, 2021
The deadlift is one of the best exercises of all time! As a matter of fact, if I had to choose one exercise to perform for the rest of my life, it would definitely be the barbell deadlift.
My role as a strength & conditioning specialist is to effectively and properly get you to perform better while staying injury-free. I'd be glad to show you HOW to deadlift in person or via my Strength and Size Program. But first, let's talk about WHY the deadlift is so gnarly.
Muscles Involved

Deadlifts work just about every muscle in your body from your toes to your dome! For those of you that have performed heavy, single rep deadlifts, you may know the feeling of seeing stars, spots, or brief flashes of white. It gets righteous real quick!
Here is a full movement analysis of the lifting and lowering phase of the deadlift:

Looking at the above slides, you can clearly see there is A LOT going on in both the lifting and lowering phase of the deadlift. Eccentric muscle contractions are when a muscle generates force while lengthening. Conversely, concentric muscle actions are those that place the muscle in a shortened position while generating force.
Being able to get into a hip hinge position, or what's known as hip extension, is absolutely critical for most sports or athletic endeavors along with activities of daily living. You ever bend over to pick something up off the floor? Then technically, you've done a deadlift. Performing it safely and with good form is a life-long skill that could potentially save your lower back.
Since the trunk is maintaining an extended position fighting the shearing force of the load during an isometric contraction (when a muscle generates force with no change in length), the lumbar erectors get worked! Strengthening the muscles of the spine that hold us erect will not only give you a sturdy posture but will likely prevent and/or resolve signs of back pain.
Conventional Deadlifts
Let's not jump the gun: not everyone possesses the hip, thoracic spine, and ankle mobility to set up properly for the deadlift. This is where regularly incorporating regular mobility and flexibility training may help out in pulling that bar off the floor by being able to get into a good starting position!
The deadlift is all about setting up to find the right amount of tension in your posterior chain (neck, back, glutes, hamstrings, calves) all while maintaining a stable, slightly extended lower back position to reduce to risk of injury. Upon lifting you should look more like the picture on the left and NOT the right:

Avoid flexing (rounding) your lower back at all costs! This could lead to serious injury of the spinal discs in your lower back which could take you out of the game for weeks if not months. Lift smarter, not harder.
Make sure at the set up your shoulders are directly over the bar with your lats and hamstrings loaded with tension. Maintain a stable, minimally arched lower back.
Remember, it's all about tension! Imagine you have sheets of paper under your armpits that you are trying to pinch there and not let go. You should feel like your hamstrings are in a stretched position. Take a deep breath, squeeze your core muscles as if you were about to take a punch in the side. From there, rip and grip driving through the heels and forcefully extending your hips!
Overview
Whether your goal is to put on some appreciable muscle, get leaner, or become a more functional human, then I'd highly suggest you start incorporating some variance of the deadlift and doing it OFTEN! The benefits far out weigh the negatives (if there are any). You can build a lot of strength that will translate to other activities while also reaping the benefits recruiting a lot of muscle groups all at once.
Dean Somerset wrote a fantastic article titled "55 Reasons Why the Deadlift Exercise is the Best of All Time" which I couldn't have written any better. It's a priceless piece that will teach you a lot while also making you LOL.
Performing the deadlift with proper technique is critical not only for exercise efficiency but for your own safety. Improper movement patterns such as rounding of the lumbar spine can place a great deal of compressive stress, increasing the chance of injury.
As trainers or coaches, we should all watch for this with our clients or athletes to prevent serious injury. Make sure to watch the order in which the joints move starting at the knees, then the hip joint, and making sure the arms remain fully extended.
Enough talk. Who's ready to lift some heavy weights?!