strenuous
adjective uk/ˈstren.ju.əs/ us/ˈstren.ju.əs/
C2 费力的，费劲的;繁重的;耗费精力的
needing or using a lot of physical or mental effort or energy
He rarely does anything more strenuous than changing the channels on the television. 他很少做比换电视频道更费神的事。
His doctor advised him not to do any strenuous exercise. 他的医生建议他不要做任何剧烈运动。
Strenuous efforts were made throughout the war to disguise the scale of civilian casualties. 整个战争期间，政府都在煞费苦心地掩盖平民的伤亡程度。