A day after announcing an independent investigation into USA Gymnastics, U.S. Olympic Committee CEO Scott Blackmun has outlined conditions with which USAG must comply or face decertification.

Citing need for a culture change, Blackmun in an email sent Thursday to the USAG board said that all 21 members of the board must resign and an interim board -- one that does not feature any current members -- must be in place by Feb. 28 or USAG will face immediate decertification, as he said USAG needs a "categorically fresh start at the board level." Under Blackmun's outlined plan, USAG must have a new, non-interim board in place within 12 months.

In addition to the investigation and the call for a replaced board, Blackmun seeks additional training for all USAG staff.

In a statement, USAG said that it "completely embraces the requirements" outlined in Blackmun's open letter.

Blackmun's emailed open letter comes a day after disgraced U.S. gymnastics doctor Larry Nassar was sentenced to 40 to 175 years in prison for seven counts of first-degree criminal sexual conduct.

Nassar pleaded guilty to 10 counts of first-degree criminal sexual conduct in November. This week's hearing was for charges that occurred in Ingham County, where Michigan State is located. Next week, Nassar will be sentenced for the three others in nearby Eaton County, where he lived and saw patients at Twistars Gymnastics.

More than 150 women and girls have come forward and said they were sexually abused by Nassar, including Olympic champions Aly Raisman, McKayla Maroney, Jordyn Wieber, Gabby Douglas and Simone Biles.

Nassar's actions and questions about how and why his abuse was allowed to go on for so long have led to the resignation of Michigan State University's president, Lou Anna Simon. Nassar was a team doctor for the Spartans' gymnastics program, as well.