Most babies will only learn to stand aged nine months or older.
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Incredible video footage shows just how he has done it.
Snorri Magnusson's 12-week course – which takes place in the swimming pool – has proved so successful Icelanders have even begun calling him the "baby whisperer".
A clip shows Snorri working his magic on four-month-old Eva who is able to stand in the palm of his hand.
Eleven out of 12 babies on Snorri Magnusson's last 12 week course were able to stand for 15 seconds
Eva performs some exercises using two small hoops held by Snorri before being hoisted into the air for about 10 seconds in the palm of her instructor's hands.
Snorri said: "The parents are always very surprised, really surprised by what their babies are able to do.
Snorri Magnusson's 12-week course has proved so successful Icelanders have begun calling him the "baby whisperer"
"When there is strength in the spine and the upper body you can do whatever. It always starts with the [straightening] training."
Snorri developed his methods working with his own twin daughters who were born in the 1990s, according to the his website.
Snorri Magnusson was the first baby swimming instructor in the Nordic country
He was the first baby swimming instructor in the Nordic country.
Eleven out of 12 babies on his last 12 week course were able to stand for 15 seconds with one able to stand for eight seconds.
Snorri's 12-week course to teach babies how to stand consists of two one-hour classes a week.