bust a gut
hustle
be at pains
take pains
give it one's best shot
bite off more than one can chew
go to the trouble
effort
overhard
bid
hard as iron
overhit
overwork
difficult
kick at the can
have a go
ettle
toughen
try as one may
overstrike
seek
slave
essay
sweat
try
attempt
assay
beaver
bust one's hump
give something a go
graft
give something a try
at pains
put a shift in
strivingly
go for
give something a whirl
overchallenge
slug away
have a stab
big
bust one's balls
hack
overstrive
take a stab at
sweat blood
rough
work like a Trojan
semihard
slave away
stab
hard going
work like a dog
pass
essaying
tool
bust one's ass
take a crack at
bust a nut
struggle
harden
lash
work like a mule
work like a horse
fight
overreach
indurate
go
sweat one's guts out
overpush
outstrain
taste
exploit
laborious
inbeat
challenging
moil
shun
uneasy
hard time
thwack
rough sledding
give it a whirl
give it a try
pedgill
triable
tryingly
pushingly
make an effort
go ham
go to extraordinary lengths
assist
tough as nails
rub along
give it some welly