Note: in AM and sometimes in BRIT, use 'burned-out'
1.
Burnt-out vehicles or buildings have been so badly damaged by fire that they can no longer be used.
...a ~ car.
ADJ: usu ADJ n
2.
If someone is ~, they exhaust themselves at an early stage in their life or career because they have achieved too much too quickly. (INFORMAL)
But everyone I know who kept it up at that intensity is burnt out.
ADJ