Large-group awareness training (LGAT) refers to activities usually offered by groups linked with the human potential movement which claim to increase self-awareness and bring about desirable transformations in individuals' personal lives. They have been described by Michael Langone as "new age trainings" and by Philip Cushman as "mass marathon trainings".
LGAT programs may involve several hundred people at a time. Though early definitions cited LGATs as featuring unusually long durations, more recent texts describe the trainings as lasting from a few hours to a few days. In 2004, DuMerton, citing "Langone (1989)", estimated that "[p]erhaps a million Americans have attended LGATs".: 39 Forsyth and Corazzini cite Lieberman (1994) as suggesting "that at least 1.3 million Americans have taken part in LGAT sessions".