gruelling Synonyms

backbreaking exhausting operose laborious taxing heavy hard punishing toilsome grueling arduous wearing stressful strenuous straining effortful stiff severe rigorous easier said than done tedious uphill trying tough wearisome tiresome wearying testing back-breaking tiring punitory penological exacting draining disciplinary difficult devastating demanding crippling clayey challenging annoying fatiguing forced painful onerous labored killing inflictive impenetrable