The athletes were aged from 12 to 19 between 1991 and 1998 when Charest, 49, allegedly assaulted them north of Montreal and in France, Austria, New Zealand and the United States.
The Crown said one of the elements Quebec court Judge Michel Bellehumeur took into account in denying bail was the need to maintain the public's faith in the legal system.
"It was also the Crown's burden to show that continued detention was necessary for the safety of (alleged) victims, witnesses or anyone else involved in the matter," Crown prosecutor Aryanne Guerin said after the ruling.
The handcuffed Charest stared down throughout much of Friday's proceedings, which were attended by his female partner.
The 56 charges include some of breach of trust. Charest was a coach with Alpine Canada's women's development team between 1996 and 1998.
Charest was originally arraigned last week on 47 charges in the alleged assaults of eight girls, while three more have since come forward.
The case returns to court April 22.
Radio-Canada reported Friday the mother of one teen tried to report Charest to police in 1998, but she said she was counselled by Alpine Canada not to do anything.
The woman, whose daughter is not one of the complainants in the current criminal case, said the organization told her it would deal with the matter and advised her to not jeopardize the girl's skiing career.
An email to Alpine Canada from The Canadian Press seeking comment went unanswered on Friday.
Alpine Canada said last week it contacted the RCMP in 1998 about sexual-abuse complaints against Charest.
The organization said in its statement last Friday it was not aware of the results of the RCMP investigation.
In the statement, Alpine Canada said it opened its own investigation early in 1998 and then told Charest he was being removed as a coach.
"A few days later, while the matter was still under investigation, Mr. Charest resigned from his position,'' it said.
"ACA (Alpine Canada Alpin) was also in contact with the RCMP in 1998 regarding this matter and provided full co-operation to the RCMP in their investigation of the complaint. ACA is not aware of the results of the RCMP's investigation.''
Montreal La Presse has reported the young women believed they were having a monogamous relationship with Charest and that tensions flared among some of them after they learned he was allegedly having sexual relations with several athletes.