You can find many articles dealing with core training that are supposedly designed to improve athletic performance. However, I have not seen any follow-up studies indicating whether performance has indeed been improved. There are probably many reasons for this lack of information.
Foremost is that checking to see if performance has indeed been improved may be flawed because the level of athlete used in the training may not be commensurate with the exercises being done. In fact, in some cases, the exercises may not even be suitable for athletes or the level of athlete used in the program.
For example, in a recent article dealing with core training for runners, the following exercises were used: Cross body lift (also known as the bird dog), Russian twists done in a seated position with the trunk at a 45° angle, and the stiff single leg deadlift. These may be excellent exercises for beginners and people seeking general fitness, but they are not suited for experienced or higher level runners or other athletes.
The reason for this is that these exercises are too” light” in that they do not stress the muscles sufficiently to be commensurate with high-level performances. In the cross body lift you only raise an arm and a leg with no extra resistance making it an excellent exercise for beginners to develop stability of the spine with static strength of the lower back muscles. Back raises executed on the Yessis Glute Ham Back machine are a much more beneficial exercise for almost all athletes.
The Russian twist done a seated position is a far cry from original Russian twists done on a Glute Ham Back machine where the body is held in a horizontal position when the shoulders are rotated. In a seated position with the torso at a 45° angle you get very little resistance and a limited range of motion to truly develop the internal and external oblique muscles. There is really no comparison between the true Russian twist and the Russian twist with the body held at a 45° angle.
The single stiff leg deadlift is best suited for balance and some strengthening of the gluteus maximus. But there is insufficient resistance to truly work these muscles to a point where they can be of great benefit in running. More effective would be the regular deadlift or even the good morning to effectively work the gluteus maximus through a full range of motion and to develop static strength of the lower back with the spine in a neutral position. Many athletes prefer doing the hip extension exercise on the Glute Ham Back machine that gives greater isolation to the hip extensors. These exercise would eliminate the need for the cross body lift.
Before recommending or using particular strength exercises it is important to first know level of the athlete for whom the exercises are intended. Only in this way can you be certain that the exercises that you are using will truly benefit the athlete. Keep in mind that high-level athletes using exercises that are not commensurate with their abilities, will experience negative results in their training rather than positive.
In order for an athlete to constantly improve performance it is necessary to keep changing and using exercises that will truly tax his or her abilities — after full adaptation has taken place from the previous exercise being used. Sadly we do not have a system of separating athletes according to their performances or training levels. It appears that when articles are written for athletes they are supposedly good for all levels of athlete. In reality this is a myth and it is about time that we recognize it as such.
Once we do this we’ll be able to have valid discussions regarding the use of specific exercises. Almost all exercises are good for developing strength or flexibility or balance or a combination of effects. But in order to get value from these exercises it is important to recognize the athlete for which they are of most benefit.
For more information in this area see Explosive Running and Build a Better Athlete.