EMS and relaxation training

One of the concepts discussed in the new Key Concepts ebook is the fact that the best sprinters not only have the ability to contract their muscles faster and with more force, but they are also more skilled at relaxing their muscles quickly.

Probably one of the best ways of training this skill is simply to perform lost of high speed sprints while staying relaxed. However I was wondering if there were other techniques that could be used?

While thinking about this, I was considering the use of EMS. Most machines have the ability to set the waveform rate in Hertz (pulses per second). So if you set it at 1 Hz, then the muscle will get a pulse every second. This means that it has to contract and then relax within that second or else you get a constant contraction (which is what we normally try to achieve with EMS training.) If we allow the muscle to contract and relax with each pulse while raising the number of pulses per second, do you think we could train the muscle to contract and relax more quickly? Anyone know if any studies have been done on this?

Frequencies closer to 1-2 Hz promote endorphin release, while frequencies closer to 8-9 Hz promote mechanical pumping of blood through the muscle. This is a well known fact in the TENS literature (pain therapy), to soothe pain and discomfort. Programs that automatically change frequency between 1 and 9 Hz during the treatment are the most popular among endurance athletes using EMS and are denominated Active Recovery. They deliver results by soothing the muscle and flushing away the byproducts of muscle adaptation.

See the EMS endurance user group of users of Globus and Compex stimulators, and in particular this postingfor testimonials of people who do it.

Active recovery helps recover much faster after intense training, and get rid of Delayed Onset of Muscle Soreness (DOMS). The Journal of Strength and Conditioning Research has very recently published this article Effectiveness of Active Versus Passive Recovery Strategies After Futsal Games. (Futsal is an indoor compressed version of soccer with many sprints).

The new installment in EMS Theory has been posted