In the photo, the father of is seen doing nude meditation on what looked like top of a mountain.
Duhamel's nude back was fully exposed in the pic.
"Taking a little break from acting to pursue my love of nude meditation," reads its caption.
Shortly thereafter, Duhamel, 42, posted another photo of himself doing meditation fully clothed and being surrounded by rabbits.
"Decided against meditating nude here because unlike these rabbits, I don't enjoy frozen nuts. #TBT," so he captioned the shot.