meaning of the word "Trucking" [closed]

What does the word trucking mean in the sentence "This chapter introduces you to your digestive system and explains exactly how your body digests the many different kinds of foods you eat, all the while extracting the nutrients you need to keep on trucking’. This is from a book called nutrition for dummies.

"Rolling smoothly along" in this sense. The informal definition is "proceeding in a casual or leisurely way".

'Truck' means to 'proceed, go, move, stroll' - by truck or otherwise (OED, U.S. slang)

1925 C. R. Cooper Lions 'n' Tigers v. 109 One by one the big wagons were trucking toward the first smoking torch at a corner of the grounds.

1941 J. Steinbeck & E. F. Ricketts Sea of Cortez xxiv. 237 We said good-by to Tiburoń and trucked on down toward Guaymas.

1979 United States 1980/81 (Penguin Travel Guides) 148 You'll still find plenty of people trucking through the streets in flannel shirts, blue jeans, cowboy hats, and boots.

Keep on Truckin' is an American idiom popular in the 1940's Swing Era. The phrase has nothing whatever to do with exhortations from the International Brotherhood of Teamsters. It was used by 'Hep Cats' who dig (understand) jazz and swing music (Tommy Dorsey, Duke Ellington, Glenn Miller, etc.). 'Truckin' has a definite movement. It is a hip-tossing, index finger-waving style of walk performed by hep cats who are 'in the groove' (in tune with the music). The phrase 'keep on truckin' (not 'trucking') still lives even after the demise of the Big Bands and Swing music, but the hip-tossing, finger-waving movement does not. The meaning today is to persist in pursuit of one's purpose (Merriam-Webster.com), just as the phrase meant in 1940 to persist in the pursuit of Swing music and Swing Dancing.