LANSING, Mich. — Coaches and others involved in youth sports will have to complete concussion awareness training at least once every three years under legislation signed into law by Gov. Rick Snyder.

The law enacted Thursday takes effect in 90 days. It updates 2012 concussion laws that require a concussion protocol for youth athletes and an awareness program for coaches, volunteers and others.

A new requirement says concussion training must be completed once every three years, unless the state Department of Health and Human Services recommends more frequent training. The state will have to periodically review the training program and make recommendations.

The law also clarifies that universities and colleges do not need to secure parental waivers for students participating in intramural sports.