punishingly

/ˈpʌnɪʃɪŋli/
adverb
  1. In a way that is extremely difficult, tiring, or demanding; to a degree that causes great hardship or suffering.
    • She worked punishingly long hours to meet the deadline.
    • The desert heat was punishingly intense, even for the locals.
    • The hike was punishingly steep, leaving everyone breathless.
Antonyms
What does "punishingly" mean? | whatsthatwordmean | whatsthatwordmean