international association for the study of pain pain definition
International Association for the Study of Pain The IASP definition of pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage"[7] is derived from a 1964 definition by Harold Merskey,[8] and it was first published in 1979 by IASP in PAIN, number 6, page 250.
No pain, no gain It came into prominence after 1982 when actress Jane Fonda began to produce a series of aerobics workout videos. In these videos, Fonda would use "No pain, no gain" and "Feel the burn" as catchphrases for the concept of working out past the point of experiencing muscle aches.[1]