dead on your feet
- exhaustedUtterly depleted of energy
- worn outDepleted through overuse
- drainedEmptied of resources
- fatiguedDrained of energy
- shatteredBroken into fragments
knackered · wiped out · running on empty · bone-tired · weary · spent · burnt out · flagging · dragging · zombie · sleepwalking · stumbling · heavy-lidded · aching · sore · overtime · double shift · insomnia
energy level
dead on your feetfull of energy
energized · fresh as a daisy · peppy · full of beans · lively
alertness
dead on your feetwide awake
Totally alert and attentive
alert · sharp as a tack · firing on all cylinders · on the ball · bright-eyed