Personially, I have a account with about the same strength lvl and I train in the Stronghold of Security. Its the 2nd floor with zombies and flesh crawlers of various lvls.
Flesh crawlers are porfitable and good exp. Crabs are great exp and good for power leveling. Then theres also experiments. Wish you luck to your training.
I belive he is adressing the issue for Strength training, but either are both good. If you are just looking for exp go with the crabs. + The zombies that are in the flesh crawler area will attack you, and don't joke they can smack 3+ . I'd go crabs, flesh crawlers at your level will make you 70-120k an hour.