As the NFL regular season begins, fans might notice a new feature on some players’ helmets—a layer of padding known as the Guardian Cap.
While Guardian Caps were first introduced during the 2022 training camps, the NFL made them mandatory for most players during practice in 2023. Recently, the league has also allowed players to wear these caps during games, aiming to reduce head injuries by absorbing some of the impact from collisions.
Indianapolis Colts tight end Kylen Granson is one player who has embraced the Guardian Cap. In a TikTok video that garnered nearly 700,000 likes, Granson explained his decision: “For me, it was a no-brainer… Why would I not add a safety measure to a helmet?”
What Are Guardian Caps?
Manufactured by Guardian Sports, Guardian Caps are designed as an extra layer of protection atop helmets. The model used by NFL players, the Guardian Cap NXT, consists of closed-cell foam covered by spandex fabric. While the company claims the caps can reduce the impact of hits in practice, they stop short of saying the product can definitively lower the risk of concussions.
Seth Jenny, PhD, an exercise science professor at Slippery Rock University of Pennsylvania, highlighted the risk of high-impact sports like football, noting the repeated trauma from hits can increase the risk of both concussions and sub-concussive blows. A 2017 study examining the brains of 202 former professional football players found that 87% exhibited signs of chronic traumatic encephalopathy (CTE), a condition linked to cognitive problems, depression, and eventually dementia.
Guardian Caps are currently used by thousands of high schools, hundreds of colleges, youth programs, and NFL teams.
Do Guardian Caps Actually Work?
There is ongoing debate over how effective Guardian Caps are in reducing harm on the field. The NFL has reported a 52% reduction in concussions during practices over the past two seasons when players wore Guardian Caps, but this research has not been shared or published.
Erik Swartz, PhD, a professor at Adelphi University and lead author of a 2022 National Athletic Trainers’ Association (NATA) statement, cautioned that the NFL’s concussion statistics might be misleading, as other factors may also contribute to changes in concussion rates. Swartz’s research also warns against relying too heavily on helmet add-ons, as they might create a false sense of security, leading to riskier behavior on the field. The NATA statement notes that there is no conclusive evidence that such helmet accessories improve safety.
Studies on Guardian Caps’ effectiveness have yielded mixed results. Jenny, along with fellow researchers, conducted a survey in 2017 among youth and high school football coaches, finding a reported 40.5% decrease in concussions after adopting Guardian Caps. Another study from Virginia Tech’s Helmet Lab suggested that thicker Guardian Caps, like those used in the NFL, reduce the force of helmet-to-helmet impacts—though these findings haven’t been peer-reviewed.
However, Swartz emphasized that lab findings do not always translate to real-world scenarios. “If you take an impact to your head, the outcome is affected by factors like the velocity and mass of the impact,” he explained, making field impacts harder to predict.
Recent studies in 2023 have also questioned the caps’ effectiveness. Research led by Kristen G. Quigley at the University of Nevada found no difference in head impact data when comparing practices where players wore Guardian Caps versus those where they did not. Another study from the same year echoed these findings, reporting no significant differences in head protection for players using the caps.
A Call for More Research
Experts agree that more data is needed before determining whether Guardian Caps truly offer enhanced protection. “I want it to work,” said Steven Broglio, PhD, director of the University of Michigan Concussion Center, “but I need to see the evidence before I can say it’s making a difference.”
As the NFL continues to experiment with Guardian Caps, the broader question of how best to protect players from head injuries remains unresolved.
