effortful
hard-fought
strenuous
laborious
with all one's might
hard going
backbreaker
toilsome
back
painless
lightning in a bottle
pedal to the metal
task
large order
tall order
reach
strive
strain
stretching
arduous
pull
go ham
put out
tool
struggle
work like a Trojan
hard
marathon
slave away
sweat blood
work like a dog
endurance contest
give it some welly
sweat one's guts out
one's socks off
Herculean
heavy lifting
laboring oar
a hundred and ten percent
mission impossible
bust a nut
marathonic
put the pedal to the metal
labor-intensive
exert
dead set
bust one's balls
go for it
bust one's hump
manual