Go Hiking and Go Trekking

hiking  / ˈhaɪkɪŋ / = the activity of going for long walks in the country for pleasure / ĐI BỘ ĐƯỜNG DÀI; HÀNH QUÂN 

                   to go hiking

                   hiking boots

trekking  = the activity of going for a long, hard walk lasting several days or weeks, especially in the mountains

                They reached the refugee camp after an arduous two-day trek across the mountains.

to go trekking (+ adv./prep.) to spend time walking, especially in mountains and for enjoyment and interest

              We went trekking in Nepal.

              During the expedition, they trekked ten to thirteen hours a day.