The verb ramble means to walk for pleasure or wander around without a definite route. It could also be used as a noun which means a walk for pleasure.

Synonyms are maunder, rattle, excursion, orouting.

The word origins from Middle English (mid 15th century) perhaps frequentative of romen meaning “to walk, go”, probably an alteration of romblen (late 14th century) meaning “to ramble”. The vowel change is probably influenced by Middle Dutch rammelen, a derivative of rammen meaning “copulate”, “used of the night wanderings of the amorous cat” and the meaning “to talk or write incoherently” is from the 1630s. It is first used as a verb in the 15th century and as a noun in 1639.

He rambles on for minutes before briefly encounter a point that he wanted to make.

I often spend my leisure time rambling and a little bit of exercising. 

He has been rambling and climbing for almost an hour now.