It is vital to strengthen the core to achieve maximum fitness. Here is some advice from Danny O’Dell and Will Brinks on how endurance athletes should rely less on consuming carbohydrates, and up their protein intake to significantly boost their performance.
What is the core?
The “core” refers to the lower back and abdominal muscles which are the connection between your upper and lower body. If it is springy and weak so will your transference of power from lower body to upper body and vice versa.

The deep trunk muscles, Transversus Abdominis (TA), multifidus (MF), Internal Oblique (IO), paraspinal, pelvic floor are key to the active support of the lumbar spine. The co-contraction of these muscles produce forces via the “theracolumbar fascia” (TLF) and the “intra-abdominal pressure” (IAP) mechanism which stabilise the lumbar spine, and the paraspinal and MF muscles act directly to resist the forces acting on the lumbar spine.
It is not just the recruitment of these deep-trunk muscles, but how they are recruited that is important. Hodges and Richardson [1] showed that the co-contraction of the TA and MF muscles occurred prior to any movement of the limbs. This suggests that these muscles anticipate dynamic forces which may act on the lumbar spine and stabilize the area prior to any movement. Hodges and Richardson showed that the timing of co-ordination of these muscles was very significant.
“The Hollow Rock” – by another name; Abdominal hollowing
Core-stability training begins with learning to co-contract the TA and MF muscles effectively as this has been identified as key to the lumbar-support mechanism. To perform the TA and MF co-contraction, you must perform the “abdominal hollowing” technique with the spine in the neutral position. Use the following guidelines:
• Start by lying on your back with knees bent
• Your lumbar spine should be neither arched up nor flattened against the floor, but aligned normally with a small gap between the floor and your back. This is the “neutral” lumbar position you should learn to achieve
• Breathe in deeply and relax all your stomach muscles
• Breathe out and, as you do so, draw your lower abdomen inwards as if your belly button is going back towards the floor. Extend your arms and legs ( think of the curved base or rocker of a rocking chair. Begin to slowly shift your body weight back and forth as in “rocking.”
• Hold the contraction for 10 seconds and stay relaxed, allowing yourself to breathe in and out as you hold the tension in your lower stomach area
• Repeat 5-10 times
Once you have mastered the abdominal hollowing lying on your back, practice it lying on your front.