From Charles Poliquin
Get the best-looking abs by training exercises that integrate all the key muscle groups of the trunk or “core.” Don’t waste time on isolation ab exercises or 15-minute ab programs. A series of research studies reveals two key points about abdominal training:
1) Core strength is necessary to prevent injury in athletes, improve mobility in the general public, and optimize functional performance in everyone.
2) The best way to build a stronger back and tighter abs is with compound movements such as squats, deadlifts, chin-ups, lunges, and Olympic lifts.
A new study in the Journal of Strength and Conditioning Research both points. This study compared muscle activation as measured with electromyography (EMG) in the trunk muscles in isolation and compound abdominal exercises.
Isolated exercises were those that only trained the proximal trunk muscles of the lumbar and abdominal region (rectus abdominus, obliques, and erector spinae), such as a crunch and lateral crunch. The integration exercises engaged the proximal trunk muscles as well as the anterior deltoid, gluteus, and thoracic erector spinae with exercises such as a plank with hand reach, mountain climber, and bird dog exercise with added resistance.
Results showed that the integration exercises activated the ab and lumbar muscles to a much greater degree than the isolation crunch and oblique crunch. They also trained a larger number of muscles, since the glutes and anterior deltoids had to make a significant contribution in order to the subjects to maintain balance and postural stability.
For example, during the plank with hand reach, rectus abdominus and oblique muscle activity were 27 percent greater than with the traditional crunch exercises. Meanwhile, the whole erector spinae was activated 2 to 3 time more during the integration exercises than the crunches, whereas the bird dog with resistance worked the greatest amount of muscle mass total, indicating the value of training with weights for strengthening the “core.”
Though not tested in this study, more effective lifts for revealing your abs and strengthening the trunk are loaded multi-joint exercises such as deadlifts, squats, and lunges. For instance, a study published last year that recorded EMG readings on the paraspinal back muscles showed that a deadlift performed at 70 percent of the 1RM load elicited average EMG activity of 88 percent and peak EMG activity of 113.4 percent. A back extension was next, producing an average EMG activity of 58 percent, followed by lunges producing 46 percent paraspinal muscle activity.
Researchers concluded that regularly training dead lifts with a load ranging from 70 to 85 percent of the 1RM in conjunction with other multi-joint “global” lifts will optimally strengthen the lower back and help prevent lower back pain. Obviously, you need to start with where you are—if you have pain in the lower back or a disc injury, rehabilitative exercises will need to come first to develop base levels of strength and structural balance throughout the muscles of the entire body. Once pain is eliminated and function is improved, use deadlifts and the other global lifts as training staples.
Gottschall, j., et al. Integration Core Exercises Elicit Greater Muscle Activation Than Isolation Exercises. Journal of Strength and Conditioning Research. 2013. 27(3), 590—596.
Colado, J., Pablos, C., et al. The Progression of Paraspinal Muscle Recruitment Intensity in Localized and Global Strength Training Exercise is not Based on Instability Alone. Archives of Physical and Medical Rehabilitation. 2011. 92, 1875-1883.