By: Trevor Fullbright
We all know the man, the myth, the Mountain, Thor. Hafþór Júlíus Björnsson, the 2018 World's Strongest Man and absolute unit, teamed up with Dr. Mike Israetel to find out what this whole "hypertrophy training" thing is all about.
Thor can practically lift a gym, so you'd expect him to be pressing crazy weights, right? Well, compared to us mortals, that's still true. But compared to his own strongman standards, this session was about something different: taking strength-based lifts and tweaking the technique so they build maximum muscle. That shift brought Thor into a whole new world of pain.
Together, they ran through a chest and arm workout designed to show how simple cues can turn your go-to exercises into brutal muscle builders.
Upper Chest Destruction
The workout started with incline dumbbell presses. Instead of grabbing the heaviest bells in sight, Dr. Mike had Thor focus on getting the pecs to do the work. Each rep was lowered into a deep stretch, with the dumbbells coming all the way down to his front delts. Thor paused there briefly before pressing back out of the hole. That emphasis on stretch, control, and slow eccentrics transformed the movement from just a heavy press into a precision chest shredder.
Turning push-ups into weapons of mass?
Next up was the humble push-up—the exercise most lifters forget about once they get under a barbell. But done the RP way, it's no afterthought. Thor elevated his hands to sink deeper into the stretch, kept his hips slightly up, and lifted his chest to open things up even more. With a controlled lowering phase and a full one-second pause at the bottom, the push-ups turned savage. Watching a giant like Thor struggle through reps was proof enough: these aren't just a warm-up.
Crushing skulls with barbells
For triceps, it was time for barbell skullcrushers. This wasn’t just about banging out reps, but really owning the technique. Thor slowed the eccentric, took the bar as low as he could manage, and worked to keep his elbows tucked so the triceps stayed under tension. With arms as massive as his, he could sink these deep, and Dr. Mike made sure every rep counted. Whether you take the bar to your forehead, behind your head, or lower toward your nose or chin, the principle is the same: take it all the way down, stretch those triceps, and chase the pump.
Wrapping it up with biceps
Finally, the session ended with one of RP’s favorites to cook your biceps: the facing-away cable curl. With the cables pulling his arms behind him, Thor got an enormous biceps stretch before curling under full tension. Dr. Mike added myorep-style work here, pushing Thor into the kind of pump that leaves your arms cramping. It got so bad Thor couldn’t even grab a drink without his biceps locking up. Thankfully, the RP athlete manager was on hand to save him from dehydration!
Why this training hits different
Thor could walk into any gym, pick up nearly any weight, and toss it around. But what made this workout special were the cues Dr. Mike gave him. The focus wasn't on just surviving the set, it was about leaning into the pain and making the muscles do the work. Slowing down the eccentric, pausing in deep stretches, and pushing close to failure maximizes growth without wasted effort.
And here's the kicker: if it works for a world-class strongman like Thor, it'll work for anyone chasing size, strength, and serious pumps.
Try it yourself
Want to see how it all went down? Check out the RP x Thor chest and arm training video for the full breakdown. But fair warning: when you train this way, you'll feel it for days.
If you're ready to bring the same science-backed approach into your own training, the RP Hypertrophy App is built on these exact principles. Every program is designed around progression that actually drives results. You don't need to be the World's Strongest Man, you just need the right plan.
