Many here have suggested extra limbs... Good suggestion!!!
HOWEVER... Not everyone here can afford them! Especially when they are first starting out. Sometimes, you just have to do the best you can, with what you have.
I have shot bows in the 50-55# range since I started bowhunting in 1976. I shot that same 50# Bear Alaskan, right up untill I bought my first compound in 1984. Had several over the next few years, but I got tired of the latest, greatest, faster, faster, gotta buy a new bow every year mentality. Used recurves were everywhere, but strings and arrows, next to impossible to find! I just quit bowhunting.
In1998, I met my good friend and former TradGang member, Joe Skipp. Joe had a basement shop acrossed the river from me. He sold new & used traditional bows, and his custom wood arrows, plus traditional accessories. He had a used 55# Kodiak Mag that I bought for $80, and I bought a dozen feather fletched cedar arrows and a deerskin shooting glove. I still remember his words... Stand close, Shoot slow, only use 1 arrow... Shoot, walk up & pull it. Think about your shot...
Joe told me I was overbowed, which I knew, but he also emphasized that with time, practice, PATIENCE, I could easily work into my new bow. 10 arrows a day, no more!!! "Come see me next week"... So I did!
The next week, he watched me shoot at the bag target in his shop. I didn't seem to be struggling? So... 10 shots in the morning, 10 shots in the evening, no more!!! "See ya next week"!
The next week, we took a few Judos out in the yard. We shot at Dandilions, lol! We would shoot, talk about our shots, walk up and get our arrows, pick another target, shoot again...
We shot for about 2 hours, but I honestly don't think we took more than 20-25 shots... Surprisingly, when we were done, I was not "fatigued" at all!!! Slow, limited, slightly increasing practice sessions is the key, to working into a heavy bow.
Just one Old Fart's experiance...