December 19, 2015

Exercise Mythology- any fictitious story, phenomenon or custom associated with exercise

Curls will allow me to isolate the biceps

The idea that you can isolate a muscle with a particular movement is incorrect. When a limb is moved parts of the body have to be stabilized to allow that movement to occur.  Some muscles begin a movement, others operate synergistically, others terminate the movement, and others become involved as fatigue sets in. All movement and stabilization are the result of coordinated muscle actions.

We should terminate the muscle isolation, and more accurately refer to certain movements as joint isolation movements.

Wearing strength shoes increases strength and flexibility

Cook and colleagues (1993) evaluated in a prospective, randomized trial the efficacy and safety of the strength shoe training regimen for increasing lower leg flexibility and strength in intercollegiate track and field participants. No enhancement of flexibility, strength, or performance was observed for participants wearing the strength shoe at the end of an eight-week training program following the suggested regimen of the manufacturer. The authors concluded that the strength shoe can’t be recommended as a safe, effective training method for developing lower leg strength and flexibility.

Janda sit-ups eliminate hip flexor activation

The Janda sit-up has recently resurfaced as an effective abdominal exercise that eliminates hip flexor activation. According to Dr. Stuart McGill, the opposite phenomenon actually occurs! During the Janda (or pressed heel) sit-up, contraction of the hamstrings causes hip extension, which means that even greater hip flexion (or psoas activation) is required to complete the movement. In addition, bent knee sit-ups actually activate the psoas more than straight leg sit-ups!

Juker and collegues (1998) investigated the claim, that activating the hamstrings during bent knee sit-ups inhibit the psoas.   This claim was not supported by the results.   Psoas activity was increased relative to comparisons with bent knee sit-ups, curl-ups and straight leg sit-ups.  Also, external oblique activity increased, and transverse abdominis increased when the technique was performed. Interestingly, rectus femoris showed no changes between the two techniques; suggesting that psoas increased activation to balance the extension hip moment resulting from the increased hamstring activity.

Heavy weight training makes you slow and inflexible

Proper resistance training enhances speed and flexibility. Take a look at sprinters and Olympic weightlifters.  Olympic lifters are among the most flexible athletes in the world.  In fact, there is no range of motion exercise any better than an overhead squat.

Hill’s equation of muscle dynamics indicates that speed of movement is dependent upon maximum strength, as measured isometrically. Several researchers have shown that speed of movement increases with muscular strength (Kusinitz and Kecney 1958; Clarke and Henry 1961; Hunold 1961).