The transverse abdominis and the abdominal obliques make up the abdominal wall musculature that work together in creating a “hoop” stress. This increases stability of the lumbar spine when moving to minimize loads. I was asked the other day, “How important is it to train the transverse abdominis in isolation?” The question was asked because an athlete was witnessed performing a strength routine and was told they weren’t activating their transverse abdominis (TA) by an observer. The observer also suggested that he could train endurance athletes to use this muscle while running to enhance stability. I was amazed and a bit skeptical when I heard this for a number of reasons. How could he tell she wasn’t using her TA? Was he looking for the drawing in or abdominal hollowing motion? If so, then that doesn’t seem like a reliable determinant in observing if this muscle is activating. Also, how does he train athletes to consciously activate their TA when running? If he does employ the hollowing technique, then I would love to see him hold that position when trying to race a 5k. TA training became a fad a few years back when it was found that low back pain patients had a correlation with motor control deficits in this muscle. Therapists and strength professionals began recommending TA isolation exercises using the “drawing in technique” to strengthen and better recruit this muscle thinking that it would enhance stability to prevent the incidence of low back pain. Problem is that it becomes increasingly difficult to hold the drawing in motion when performing multi-planar tasks (like running) and as the abdominal wall stiffens to maintain stability, the abdominal wall muscles bind together. So why perform isolation training for a muscle that acts in accordance with its abdominal brethren? Stuart McGill, probably the world’s foremost expert and researcher on low back and abdominal mechanics, found that the abdominal bracing technique is much more effective than the abdominal hollowing technique as it recruits the obliques in addition to the TA as opposed to the TA by itself. Bracing is performed by creating a co-contraction tightening of the TA and obliques without drawing in or pushing out the abdominals. Try it for yourself: Stand on one foot and have someone push you lightly from behind, using both the hollowing and bracing techniques. Do you have more stability when bracing or when hollowing? It is also important to remember that when referring to stability (and which muscle is most important for this task), it is always relative to a specific moment in time. So when training the transverse abdominis for sports performance stability, it is better to train the abdominal wall as a group utilizing planks, side bridges, and leg extensions from a quadruped position, than trying to train each muscle in isolation.