Bricks are a term used to describe transition training for triathletes. The usually refer to a bike/run brick, but can also be used to refer to swim/bike bricks or other combinations.
The term came about in the late 80’s early 90’s. There are a couple of idea’s about where the term came from. Some claim term is a nod to Dr Matt Brick who won the world duathlon champs in both 1991 and 1992 (back in the old school 10/60/10 format). And other claim it comes from a group of top tier triathletes including the likes of Mike Pigg, Mark Allen, Scott Molina and a few hangers on, who used to train together, apparently someone in the group used to sing “Another Brick In The Wall” by Pink Floyd whilst training. The idea that the training session was brick that was helping to build their wall of training.