energetically
The phone rang, and she rose lethargically and went to answer it.
Two boys were assembling chairs, working lethargically.
They lethargically recorded some demos, but their heart wasn't in it.

SMART Vocabulary: related words and phrases

Tired and making tired
all in
anti-fatigue
at your worstidiom
be dead on your feetidiom
be fit/ready to dropidiom
finish something off
fit to dropidiom
fragile
frazzled
gassed
haggard
knackered
shell-shocked
sleep-deprived
sleepily
sleepiness
sleepy
stonkered
strung out
zonked