A 36-year-old personal trainer who had sex with her teenage client for two years, fainted after being sentenced for up to 15 years in prison.

Suni Faith Andersen, who earlier pleaded guilty to two counts of forcible sexual abuse, passed out and hit her head on a table after hearing the sentence in a Utah courtroom on Tuesday.

Andersen began her illicit relationship with the boy when he was 14 and continued until he was 16.

According to KSL.com, Andersen began the relationship after making sexual advances towards the boy.

The pair then had sex during regular training sessions in Andersen's home.

After she passed out, the court took a 15-minute break before Andersen was revived.

According to the St George Spectrum, the boy gave evidence at the hearing, adding, I have to walk through the halls of my high school knowing that people know what happened, wondering what they're thinking.

Andersen's husband, a high-school football coach, was also present at the hearing and pleaded for leniency.

According to reports, the teen victim's mother called Andersen, A pedophile of the worst kind.

While holding up the picture of her son taken when he was 14, she added: This is a picture of my son when he was 14 years old.

Look. Suni, look. Does this look like someone a 34-year-old adult woman would want to have a relationship with.

Andersen will serve between 1 and 15 years.