namáhavý znamená v angličtina

strenuous▼(requiring great exertion)
adjective
[UK: ˈstre.njʊəs] [US: ˈstre.njuːəs]

uphill▼((by extension) difficult or laborious)
adjective
[UK: ˌʌp.ˈhɪl] [US: ˈʌp.ˈhɪl]