The mother of a teen track star expressed disbelief after a New York medical examiner ruled the girl died from an overdose of muscle cream.

"She did not use it to excess, by no means," Alice Newman told FOX News.

Arielle Newman, 17, died April 13. The teen was a cross-country runner at Notre Dame Academy on Staten Island. The New York City medical examiner ruled Friday that she died after her body absorbed high levels of methyl salicylate, an anti-inflammatory found in sports creams such as Bengay and Icy Hot.

The medical examiner's spokeswoman, Ellen Borakove, said the teen used "topical medication to excess." She said it was the first time that her office had reported a death from using a sports cream.

Newman, who garnered numerous track awards, had gone to a party the night before she died, then returned home and spent hours talking with her mother.

Methyl salicylate poisoning is unusual, and deaths from high levels of the chemical are rare.

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"Chronic use is more dangerous than one-time use," Edward Arsura, chairman of medicine at Richmond University Medical Center, told the Staten Island Advance on Friday. "Exercise and heat can accentuate absorption."

Dr. Ronald Grelsamer, of Mount Sinai Medical Center, said Newman had a very abnormal amount of methyl salicylate in her body.

"She either lathered herself with it, or used way too much, or she used a normal amount and an abnormal percentage was absorbed into her body," he said.

Alice Newman said she still couldn't believe her daughter's death was caused by a sports cream.

"I am scrupulous about my children's health," she told the Advance. "I did not think an over-the-counter product could be unsafe."

The Associated Press contributed to this report.