strenuous (effort, behavior)

schwer (a) (effort)

schwierig (a) (effort)

lästig (a) (effort)

drückend (a) (effort)

beschwerlich (a) (effort)

anstrengend (a) (effort)

mühselig (a) (effort)

schweißtreibend (a) (effort)

unermüdlich (a) (behavior)

énergique (a) (behavior)

ardu (a) (effort)

pénible (a) (effort)

lourd (a) (effort)

épuisant (a) (effort)

dur (a) [m.] (effort)

laborieux (a) (effort)

zélé (a) (behavior)

attivo (a) [m.] (behavior)

arduo (a) (effort)

difficile (a) (effort)

strenuo (a) (effort)

duro (a) (effort)

fervente (a) (behavior)

activo (a) [m.] (behavior)

arduo (a) (effort)

penoso (a) (effort)

trabajoso (a) (effort)

laborioso (a) (effort)

dificultoso (a) (effort)

difícil (a) (effort)

vigoroso (a) (behavior)

energiek (a) (behavior)

veeleisend (a) (effort)

moeilijk (a) (effort)

lastig (a) (effort)

zwaar (a) (effort)

hard (a) (effort)

vermoeiend (a) (effort)

fervent (a) (behavior)

energisk (a) (behavior)

svår (a) (effort)

mödosam (a) (effort)

besvärlig (a) (effort)

betungande (a) (effort)

hård (a) (effort)

tryckande (a) (effort)

ivrig (a) (behavior)

pesado (a) (effort)

ativo (a) [m.] (behavior)

duro (a) [m.] (effort)

difícil (a) (effort)

árduo (a) (effort)

trabalhoso (a) (effort)

laborioso (a) (effort)

fervoroso (a) (behavior)