Would someone correct this, please

In 1997, Mukhtar Gusengadgiev was listed in the Guinness
World Records as the most flexible man of the planet.
He has his own training method of developing body flexibility.

Slavik Komakha is the only one certified student who got received his
diploma after passing a difficult exam.
This diploma gives an opportunity certifies him to use a  the training method
of "The most Flexible Man of the Planet."

After a long course of studying at Moukhtar’s personal trainings
and workshops, Slavik has been teaching at FlexDerekSchool in
Kiev. Many famous show business stars, dancers, yoga
and martial art coaches are trained here.

There are no limits, restrictions, or boundaries in flexibility
development. There is the only one barrier - our mind.
If you have a flexible mind, you get a flexible body.
Until a person learns to release the mind, his body is will be stiff and
constrained, as if it was shackeled.