How to Bulk Up: The Complete Guide for Skinny Guys

I was underweight well into my twenties. I would read guides about how to build muscle, and I would try them, but they wouldn’t work. They would urge me to bulk slowly and leanly, filling me with a fear of fat gain. But I wasn’t scared of gaining fat. That wasn’t my problem.

I wanted to build muscle fast—as fast as I possibly could. I didn’t care if my gains were perfectly lean, I just didn’t want to be skinny anymore. So, I ignored the conventional wisdom. I bulked more aggressively, gaining 20 pounds in 3 months, and to my great surprise, I didn’t even gain a noticeable amount of body fat.

Shortly after that, I came into contact with Marco, a strength coach helping college, professional, and Olympic athletes bulk up during their off-seasons. He was as naturally skinny as I was. He taught me how to bulk the proper way. I gained another 25 pounds in another 3 months.

Since then, we’ve helped 15,000 other skinny guys replicate those same results. In this article, we’ll teach you how you can do it, too.

As he makes his way through the jungle of muscle growth, a skinny man may feel like a small, fragile bird in a world of much larger beasts. The obvious solution is to become a man again, rediscovering the wonder of human movement and growth, using that wonder to kindle the spark of strength within. The less obvious solution is to become an eagle.

The term “skinny” refers to people with lower-than-average amounts of muscle mass and body fat. This leaves them unencumbered by excess weight, allowing them to move with a lightness of step, evading the notice of enemies.

Some individuals are predisposed to skinniness, their bodies primed to resist the accumulation of mass. This can be due to a number of factors:

Skinniness often stems from a natural tendency, but our bodies are capable of adapting to the burdens we place upon them. You can stimulate muscle growth by challenging your muscles. Your stomach can adapt to hold more food. Your gut can be strengthened. You can overcome your metabolism through a process known as bulking.