grueling
adj : characterized by toilsome effort to the point of exhaustion;
especially physical effort; "worked their arduous way
up the mining valley"; "a grueling campaign"; "hard
labor"; "heavy work"; "heavy going"; "spent many
laborious hours on the project"; "set a punishing pace"
[syn: {arduous}, {backbreaking}, {gruelling}, {hard}, {heavy},
{laborious}, {labourious}, {punishing}, {toilsome}]