CALIFORNIA ? Gov. Arnold Schwarzenegger on Friday signed a bill barring high school athletes from using certain nutritional supplements, a year after he vetoed similar legislation.

The action came after the governor was criticized for having a multimillion-dollar contract with muscle magazines that rely on advertising from supplement companies. Critics said the arrangement posed a conflict of interest.

The law prohibits high school athletes from taking three nutritional supplements: synephrine, ephedra and DHEA. It also requires students to sign a pledge not to use the supplements and bars supplement manufacturers from sponsoring school events.

The Republican governor vetoed similar legislation last year, but Schwarzenegger spokeswoman Margita Thompson said this year’s version corrected flaws in the old bill. She said the banned substances were not clearly defined in the earlier version.