KARE - It's good to see young people working out.
At Minnesota's Edina High School on Monday, athletes were lifting weights to be in top physical form.
Football player Peter Heffelfinger said a lot of athletes he knows are concerned with muscle mass.
"I think it's more of a pressure to be bigger and get that starting spot rather than look good," Heffelfinger says.
But there are new concerns that some teens are going too far. A new University of Minnesota study published in the journal Pediatrics shows teens are doing more to add muscle.
Researchers say the numbers are higher than previous research has shown.
Read more at KARE11.com.