gruelingly

/ˈɡruːəlɪŋli/
adverb
  1. In a way that is extremely tiring, demanding, or difficult.
    • She worked gruelingly through the night to meet the deadline.
    • The soldiers marched gruelingly across the desert under the hot sun.
    • The team trained gruelingly every morning before sunrise.
Antonyms
What does "gruelingly" mean? | whatsthatwordmean | whatsthatwordmean