There are no mandatory exercises. There is no rule that says you have to bench, squat, or deadlift. With that being said, there is one strength movement that I believe just about anyone can benefit from regardless of their training experience -- one that can improve strength, posture, muscle mass, motor patterning, and even flexibility. That movement is the Romanian Deadlift, or RDL.
The many benefits of the RDL make it an excellent foundational movement in any exercise program. This is well understood by high-level trainers such as Paul Carter, celebrities who want to look and perform to a high standard like Henry Cavill, and certified maniacs like WWE superstar/YouTube legend Eric Bugenhagen.
Strength, Muscle, Flexibility
While the RDL is typically thought of as a hamstring and glute exercise, it develops head-to-toe strength throughout the posterior chain and stimulates a huge amount of muscle mass. The upper back stabilizes the bar and the shoulder girdle itself, calling upon the rhomboids, traps, lats, and several smaller muscles. The lower back and abdominal musculature work isometrically to stabilize the spine. The glutes and hamstrings act as the primary movers, producing hip extension. The hamstrings in particular are put under a significant weighted stretch at the bottom of the movement, which is a potent stimulator of muscle hypertrophy, in addition to its flexibility benefits.
Motor patterning, Posture
Even the most sedentary person will have to bend over to pick something up at some point. The RDL closely resembles the movement pattern required to pick up an object from the floor: tight core, neutral spine, controlled extension of the hips. Training the RDL can teach an individual to use their glutes and hamstrings effectively, move with safer patterns in day-to-day life, and avoid the compromising positions that can easily lead to back injury. By strengthening the core, back, and glutes, the RDL also allows a person to maintain better posture throughout the day.
How to Implement the RDL:
Execution:
Do NOT round the lower back. This is a surefire way to get injured. However, there is no need to over-arch (over-extend) the back either. A neutral to slightly arched back, with braced abs should be used. When thinking about bracing the abs, imagine someone is about to punch you in the stomach.
Equipment:
The barbell RDL typically allows for the heaviest loads to be used, but the RDL can be performed effectively with a variety of implements, including dumbbells, kettlebells, the trap bar, the smith machine, and a variety of other machines. For the barbell variation, I'd recommend using straps as the weights get heavier if you find that your grip gives out prematurely.
Programming:
RDLs are most useful in the 4-10 rep range. Occasionally venturing above or below this rep range is fine, but will put you more at risk for breakdowns in form. This is not a movement that should be performed to failure, and it requires patience when it comes to increasing loads. Every rep should be performed perfectly.
When you first begin performing these, I would NOT recommend overdoing the volume. After warm-ups, I generally find that 1-2 hard sets are plenty to get the job done. The weighted stretch can cause a tremendous amount of muscle damage, and will make you incredibly sore.
