STRENUOUS

[adjective] - demanding or using a lot of physical or mental effort or energyHe rarely does anything more strenuous than changing the channels on the television.She has been a strenuous campaigner for animal rights for more than twenty years.His doctor advised him not to take any strenuous exercise until he had completely recovered.Strenuous efforts were made throughout the war to disguise the scale of civilian casualties.Despite strenuous efforts to revive him, he was dead before the ambulance arrived.Surprisingly, the most strenuous opposition to the tax changes has come from the people who will benefit most from them.