We know it is important to have strong abdominal and trunk muscles, which has become known as the "core". But do we need to be doing isolated exercises for these muscles or can we get away with just doing whole body lifts that work everything?
Well I will be the first to admit that I always thought you need to do separate exercises for your trunk muscles to fully develop them but maybe we don't? The study below sheds some light on the issue.
Be Well,
Mike Reid
"The Difference in Trunk Muscle Activation During Dynamic Weight Training Exercises and Instability Exercises
The purpose of the following study was to determine the extent of trunk
muscle activation during dynamic weight training and isometric
instability exercises.
Sixteen subjects performed squats and deadlifts with 80% of 1
repetition maximum (RM), as well as supermen, sidebridges, squats and
deadlifts with body weight only. Electromyographic (EMG) activity was
measured in the following muscle groups: lower abdominals, external
obliques, upper lumbar erector spinae, and lumbar-sacral erector
spinae.
The results of the study indicated that EMG activity of the
lumbar-sacral erector spinae during the 80% 1RM squat significantly
exceeded EMG activity for the same muscle during the 80% 1RM deadlift,
bodyweight squat and deadlift, superman, and sidebridge. EMG activity
of the upper lumbar erector spinae during the 80% 1RM deadlift
significantly exceeded the EMG activity for the same muscle during the
80% 1RM squat and all body weight exercises. There were no significant
changes in EMG activity for the lower abdominals or external obliques.
The researchers concluded that because the lumbar-sacral erector
spinae and upper lumbar erector spinae muscle activation during the 80%
squat and deadlift exceeded muscle activation during body weight
exercises, instability exercises may not be necessary to augment core
stability training, so long as individuals perform upright, resisted,
dynamic exercises."
Hamlyn, N., D.G. Behm, and W. B. Young. Trunk muscle activation
during dynamic weight-training exercises and isometric instability
activities. Journal of Strength and Conditioning Research, 21(4), 1108–1112. 2007.