Pull-Ups: Can You Build a Balanced Physique with Just One Exercise?

Pull-ups are one of the most complete and effective exercises in calisthenics. Primarily targeting the lats and biceps, this movement also engages secondary muscles such as the traps, deltoids, core, and even the pecs. But here’s an interesting question: can you build a balanced and impressive physique by doing only pull-ups, without incorporating other exercises into a full routine?

While it’s not the most efficient approach to training, consistent high-volume work can yield surprising results. Over time, even secondary muscles, typically just stabilizers, can receive enough cumulative stimulus to grow. This raises the fascinating idea of how massive, consistent repetition of a single exercise can impact muscle development in ways we often overlook.

The Case of Gero Arias

Most people reading this article have likely heard of Gero Arias, an Argentine athlete who, in 2023, set out to add one pull-up per day to his routine without ever coming off the bar. To everyone’s surprise, he managed to reach 281 days. His journey turned him into a viral sensation across social media platforms. In fact, it may be the most viral phenomenon in calisthenics history, with Gero uploading two or three videos daily—each surpassing a million views.

Fast forward to 2024, and Gero is attempting the challenge again. This time, he’s closing in on the finish line, as we’re currently on day 347 of 366 (leap year). But what’s truly capturing attention is his remarkable physical transformation.

A Climber’s Body Transformed

Gero’s background is in climbing, and his physique originally reflected that: lean, wiry, and highly defined. Given that the pull-up challenge excludes any other exercises—something he’s repeatedly clarified—you’d expect significant growth in his back and biceps, the primary muscles targeted by pull-ups.

Surprisingly, over these two years, Gero has gained noticeable muscle mass across his entire upper body, including his pecs, anterior deltoids, traps, and triceps. The transformation has been especially striking this year, even as he continues to insist he does nothing beyond pull-ups. How is this possible? Could he be secretly training other exercises? Or is there an overlooked factor at play?

What Muscles Do Pull-Ups Work?

As mentioned earlier, pull-ups primarily engage the lats and biceps, with secondary involvement of the upper back and forearms.

That said, this doesn’t mean only these muscles are active during the movement while the rest of the body remains idle. Throughout the pull-up, small stabilizations and synergistic actions occur, lightly activating nearly every muscle in the upper body at some point.

For someone doing a typical workout of 3 sets of 10 pull-ups twice a week, this minor activation isn’t enough to generate significant muscle growth. If that’s your volume and you’re not doing additional exercises, you’ll likely see development in your lats and biceps—but not much else.

Gero’s Insane Pull-Up Volume

In Gero’s case, however, the sheer volume of pull-ups he performs weekly is astronomical—especially in the later months of the year.

For example, by April of both 2023 and 2024, he was already doing over 100 pull-ups daily, increasing progressively. That’s more than 700 pull-ups per week or over 6,000 accumulated for the year. By July, this number had grown to over 200 pull-ups daily—1,400 weekly. And by November, he was surpassing 300 pull-ups per day, or 2,100 weekly, totaling over 45,000 pull-ups annually.

If he completes the 366-day challenge in 2024, he will have performed 67,161 pull-ups in one year, with 2,541 in the final week alone. A calisthenics lover’s dream Christmas, indeed.

The Role of Secondary Muscles in Massive Repetition

For someone like Gero, performing hundreds of pull-ups daily, thousands weekly, and tens of thousands annually, even those seemingly insignificant stabilizing contractions of muscles like the pecs, deltoids, and traps add up. Over time, these auxiliary muscles receive a powerful enough stimulus to promote growth.

This explains why Gero, after two years of this challenge, has achieved remarkable upper body development. Interestingly, his lats, biceps, and forearms are likely experiencing what would typically be classified as overtraining. If Gero’s goal were purely hypertrophy, he could achieve similar results with far fewer pull-ups.

Efficiency and Diminishing Returns

At a certain point, adding more and more repetitions results in diminishing returns. The excessive volume may yield fewer benefits compared to a structured program avoiding overtraining.

Ironically, secondary muscles like the pecs might actually be receiving an optimal stimulus. Hundreds of small contractions every day could equate to three or four sets of targeted exercises. Of course, this method is far from efficient, as it requires an enormous number of pull-ups to achieve the right stimulus—with all the fatigue that entails. However, this does offer an explanation for Gero’s impressive upper body development.

Conclusion

Gero Arias’s incredible pull-up challenge has not only broken endurance records and gone viral in the calisthenics community but also raised fascinating questions about the impact of massive repetition on muscle growth. His physical transformation—particularly in muscles not traditionally emphasized by pull-ups—challenges conventional thinking about how repetitive, consistent minor contractions can accumulate into a significant stimulus.

While this approach isn’t the most efficient for hypertrophy, Gero’s experience demonstrates that even unconventional methods can deliver surprising results. Beyond debates on training methods, one thing is clear: his challenge has inspired thousands and will remain a unique milestone in calisthenics history.

If you want to work on a powerful pull-up routine with progressive overload and different variations, check out the EVO Back and Biceps Routine available on Calisteniapp. You can find it here.

By Yerai Alonso