May 27, 2026, 7:03 pm | Read time: 4 minutes
To this day, Arnold Schwarzenegger is considered an icon of bodybuilding–especially his legendary arms have influenced generations of fitness enthusiasts. His son Joseph Baena is already following in his footsteps. Now, one of his workouts on a special curl machine for the biceps is drawing attention. FITBOOK author Tony Poland explains the benefits of this exercise along with fitness coach Markus Bremen.
Schwarzenegger Family Relies on the Preacher Curl Machine
When it comes to impressive upper arms, one name has stood out for decades: Arnold Schwarzenegger. The seven-time Mr. Olympia made bodybuilding popular worldwide and set new standards with his iconic biceps. His son Joseph Baena also trains today using many of the same old-school methods as the “Terminator” star once did. A classic curl machine seems to have a permanent place in his arm training.
Normally, Joseph Baena relies on free weights like dumbbells and EZ bars for upper arm training. Recently, however, the bodybuilder switched to a machine curl variant that aims to maximize tension and control throughout the entire movement. The device resembles a preacher curl machine but lacks the angled arm supports. Instead, Baena performs isolated curls, as seen in the U.S. magazine Men’s Health.
The machine stabilizes the upper arm, ensuring the biceps are constantly loaded throughout the repetition. At the same time, swinging movements are almost entirely eliminated, forcing the muscle to do nearly all the work itself. Arnold Schwarzenegger regularly used isolated curl variants during his active years to shape his famous biceps peak.
What Makes the Exercise So Effective
The advantage of this exercise is that the machine better fixes the upper arm, significantly reducing swinging movements. This keeps the biceps under constant tension throughout the movement, especially in the stretched lower part of the repetition. At the same time, the biceps head can be more precisely isolated, while Joseph Baena has more control over the pace and range of motion. This intense stimulus in the stretched state is considered by many trainers to be an important factor for muscle growth.
“Current research on hypertrophy clearly shows that training in the stretched muscle state generates particularly strong growth stimuli and metabolic stress–both central mechanisms behind the pump phenomenon,” explains sports scientist and fitness expert Markus Bremen. “The mechanical tension in the stretched state is structurally greater,” he adds.
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“Less Is More” in Biceps Training
Since the biceps is a relatively small muscle group compared to the triceps, often just one targeted training session per week is enough to set effective stimuli. More than two intense sessions should generally not be necessary. As is often the case in strength training, continuity and clean execution are more important than the highest possible training frequency or heavy weights.
What matters most are varied exercises and different movement angles, as well as controlled execution with a clean pace and full range of motion. Equally important is the progressive increase in load–that is, gradually increasing the weight. For well-developed upper arms, it is also advisable to regularly integrate pulling exercises like pull-ups or rowing into the training.
Also interesting: Arnold Schwarzenegger’s 20-minute workout makes the muscles burn
Old-School Exercise for Serious Muscle
The preacher curl machine may not be among the most modern equipment in the gym, but it is still considered highly effective. Those who want to train the biceps as isolated as possible and generate maximum muscle tension will find a biomechanically strong exercise here.
“Constant tension, maximum isolation, low risk of injury–hard to beat for the pump and suitable for almost any training level,” summarizes Markus Bremen and continues: “In combination with an exercise that emphasizes the upper range of motion, such as incline curls on the incline bench, a more complete training stimulus for the entire biceps is created.”
The fact that both Arnold Schwarzenegger and his son Joseph Baena continue to rely on this exercise shows that some classics still work excellently decades later.