1. (adjective) requiring great physical effort

• arduous
• backbreaking
• grueling
• gruelling
• hard
• heavy
• laborious
• operose
• punishing
• toilsome
• arduous
• straining
• strenuous
• dragging
• exhausting
• tiring
• wearing
• wearying
• heavy
• labored
• laboured
• labor-intensive
• labour-intensive
• leaden
• plodding
• sisyphean

1. (adjective) requiring great physical effort

• difficult
• hard

1. (adjective) requiring great physical effort

• effortfulness

1. (adjective) requiring great physical effort

• effortless