https://www.youtube.com/@jmi75leja/videos
The guy in this video benched his own bodyweight 66.5kg/156lbs x 601 times and he also benched 95kg/210lbs x 80 repetitions without ever racking back the bar with decent range of motion and apparently he does it very often, multiple times a month, each set completely non-stop .
How does one achieve such feats of strength? My max bench now is 110kg x 1 time but I only do Larsen press because I can't arch my back.
Progressive overload and practice. If you want to bench more, you need to bench more.
You can bench 110kg x 1 rep, great. How much weight can you rep 10 times? How much can you rep 50?
Find a weight you can rep 600 times and slowly increment weight over time (2.5kg every session, perhaps less often?). Every time you add weight, your reps probably will drop: use the same weight until you can rep 600 and only then increase the weights again, and so on.
You probably don't want to do this every day, you might need at least a day off to rest before you try it again, probably more as the weight increases.
(I wouldn't personally say the form from the guy in the video is great. He's using a powerlifter's arch, quite some leg drive and bounces the bar off his chest to reduce the range of motion, and takes a long pause at the top. All this contributes to making the lift less tiring.)
Lastly, why would you want to do so many reps? Sure there are more efficient ways to achieve better endurance / strenght / chest hypertrophy. And that's just bench press, do you plan to train other body parts after spending 1h just bench pressing?
