Do Headguards Actually Protect Your Brain?

Oct 13

8 min read

I've always thought we should be careful about the claims we make in combat sports, particularly when those claims involve safety. We spend a lot of time discussing technique, training methods, conditioning, and equipment, but sometimes we accept an idea because it sounds reasonable rather than asking whether it actually produces the outcome we want.

Protective headgear is a good example. It seems obvious that putting more padding around the head should make getting hit in the head safer. The problem is that the human brain is considerably more complicated than that.

The NFL's Guardian Cap has brought this question into the spotlight. These padded covers fit over football helmets and are designed to reduce impact forces during collisions. They look like a sensible solution to a serious problem, and it's easy to understand why people would welcome a piece of equipment that promises additional protection. But research into Guardian Caps, along with studies of padded headgear in rugby, raises an uncomfortable question: Are we actually reducing brain injuries, or are we measuring improvements in impact mechanics and assuming those improvements translate into better outcomes?

That distinction matters to anyone who coaches a sport involving repeated head impacts.

What Did the Stanford Researchers Find?

In 2023, researchers at Stanford University investigated whether Guardian Caps reduced head impacts in football players. They began with laboratory testing, using an instrumented dummy head to measure the effects of impacts with and without the padded cover.

The results were mixed. Guardian Caps provided little reduction in straight-on impacts, although they offered some additional protection during angled impacts. Under those angled conditions, the researchers measured an average improvement of approximately 15–20% in the tested conditions. The benefit varied, however, and some impacts actually produced more severe measurements with the cap in place.

Laboratory testing is useful, but it doesn't necessarily tell us what happens when real athletes collide during practice. To investigate that question, the researchers also used instrumented mouthguards to measure head motion in Stanford football players. They compared five linebackers from the 2019 season, when Guardian Caps weren't being used, with five from the 2021 season, when they were. Across 97 observed head-to-head collisions, the researchers found no statistically significant reduction in measured impact severity.

The study was small, and it did not establish whether Guardian Caps did or did not prevent concussions. It did, however, illustrate the gap between a promising laboratory result and a demonstrated real-world benefit.

Other research has produced mixed findings, too. A study of high-school football players found no significant reduction in practice concussion risk associated with Guardian Cap use. On the other hand, a 2025 study of NFL preseason practices reported a substantial decline in concussion rates among positions required to wear the caps. That finding is worth taking seriously, although the researchers could not establish that the caps themselves caused the reduction.

So I wouldn't argue that Guardian Caps have been proven useless. The evidence doesn't support that conclusion. The more defensible criticism is that we shouldn't treat improved performance on selected impact measurements as proof that a product prevents brain injuries.

And this isn't just a football problem.

Rugby Has Been Asking the Same Question

Rugby has a long history of using padded scrum caps, and researchers have examined whether they reduce the risk of concussion. The results are not encouraging for anyone who believes soft headgear provides reliable protection against brain injury.

A 2023 systematic review and meta-analysis examined randomized controlled trials involving rugby and soccer players. Across the included trials, researchers analyzed 6,311 players and 173,383 hours of exposure. The pooled results showed no reduction in sport-related concussion associated with headgear. The estimated risk ratio was 1.03, meaning the observed concussion rate was essentially unchanged between the groups. The confidence interval still allowed for some possible benefit or harm, so this doesn't prove that the true effect is precisely zero. But the evidence did not support using headgear as a concussion-prevention measure.

A separate study examined four seasons of professional men's rugby union in England, including 1,117 players and 417 diagnosed concussion cases. Researchers reviewed match footage to determine whether players were wearing headgear. They found no significant association between headgear use and lower concussion risk. Players wearing headgear also did not return to play more quickly after a concussion.

These findings are important because they move the discussion beyond a laboratory demonstration that padding can change the mechanics of an impact. They examine what we're ultimately interested in: whether athletes wearing the equipment experience fewer concussions.

The evidence doesn't show a reliable protective effect.

We should still be precise about what that means. Rugby scrum caps are not identical to Guardian Caps, and neither product represents every possible design of protective headgear. We cannot assume that every piece of padding will perform identically. But rugby provides a useful warning against assuming that soft padding must prevent concussion simply because it absorbs some impact energy.

Headgear Has Benefits. That Isn't the Same as Brain Protection.

At this point, someone will reasonably ask whether I'm arguing that athletes shouldn't wear headgear at all. I'm not.

The Association of Ringside Physicians published a position statement on headguard use in combat sports in 2024. The authors concluded that headguards are useful for reducing facial lacerations and certain ear injuries, but that they should not be relied upon to prevent concussion or other traumatic brain injuries. They also noted that changes in athlete behavior toward greater risk-taking might offset some potential benefit from the equipment.

That is a sensible distinction. If I want to reduce the likelihood of a student getting cut during sparring, headgear can be useful. If a wrestler wants to protect his ears, there is a good reason to wear it. Those are legitimate benefits, and we shouldn't dismiss them simply because the equipment hasn't been shown to prevent concussion.

The problem arises when we take those benefits and turn them into a broader promise of brain protection. Padding can reduce some forces under certain conditions, but a concussion involves complex biomechanical and physiological processes. The brain can move and deform inside the skull, and the effects of an impact depend on more than one measurement of acceleration. Repeated exposure adds another layer of complexity.

We also have to acknowledge the limits of the research. Studies that measure impacts or diagnose concussions cannot, by themselves, tell us precisely how a particular piece of equipment affects someone's risk of developing long-term neurological problems decades later. We shouldn't pretend to know more than the evidence allows.

But we also shouldn't tell athletes that their brains are protected when we don't have good evidence to support that claim.

The Problem With Feeling Too Safe

There's another issue here that I think deserves more attention: how protective equipment changes the way people behave.

In combat sports, I've seen athletes treat headgear as if it gives them permission to take risks they might otherwise avoid. They become more willing to exchange punches, walk into contact, or absorb shots because they believe the padding offers protection that it may not actually provide. The equipment doesn't have to make someone objectively less safe to create a problem. If it makes him feel safer than he really is, that false confidence can influence his decisions.

This is often discussed as risk compensation: people may change their behavior in response to what they perceive as a reduction in danger. It's a plausible explanation for why protective equipment might fail to deliver the full benefit we expect. But we should be careful not to claim that every athlete behaves this way or that the rugby studies prove headgear causes recklessness. The Association of Ringside Physicians identifies behavioral change as a potential concern, not a settled explanation for the findings.

Still, coaches don't need to wait for a definitive answer to recognize the practical problem. If a student believes headgear makes repeated blows to the head safe, we have a responsibility to correct that misunderstanding. We shouldn't encourage people to take additional risks simply because they have put on protective equipment.

This is especially relevant to MMA and boxing, where head contact isn't an accidental feature of the sport. Striking the head is an intentional part of competition. The question is how much unnecessary exposure we introduce during training while trying to prepare people for it.

What Does This Mean for MMA Training?

I don't think the answer is to eliminate headgear. I think the answer is to stop treating headgear as a substitute for good coaching decisions.

We can decide how often students spar, how hard they spar, how much head contact a session involves, and whether every training session needs to include hard exchanges. We can teach defense, distance management, timing, and composure through technical drills and controlled resistance. We can use sparring to develop the skills that matter without assuming that every round has to become a test of how much punishment someone can absorb.

Competition brings risks that cannot be completely removed without changing the nature of the sport. Preparing someone to compete also requires some exposure to realistic conditions. But that doesn't mean every student needs the same exposure, or that unnecessary head impacts are an unavoidable cost of becoming skilled.

At BLAST, I want students to learn to fight well, train hard, and develop skills that hold up against resistance. I also want them to be able to train for years without accumulating avoidable damage. Those goals aren't in conflict. In fact, I think a coach who takes long-term development seriously should be looking for ways to improve skill while limiting unnecessary risk.

Headgear can have a place in that process. It just shouldn't be used to justify harder or more frequent head contact on the assumption that the padding makes it safe.

Don't Confuse Protection With Safety

The Guardian Cap research and the rugby literature illustrate a broader problem with how we think about safety. We see a product designed to absorb impact, observe that it performs well in some laboratory tests, and are tempted to conclude that it makes the activity safer. But that conclusion requires evidence about the injuries we actually want to prevent.

If the purpose is to reduce cuts, we should look at evidence about cuts. If the purpose is to prevent concussions, we need evidence about concussions. And if we're concerned about cumulative brain injury, we should be honest about how little we can infer from a single impact measurement.

I don't want to dismiss equipment that offers genuine benefits. I want us to be precise about what those benefits are. A product can be useful without solving the problem it is marketed to solve, and a reduction in one kind of injury doesn't mean we've eliminated another. We should also be cautious about the possibility that feeling protected encourages behavior that undermines some of the intended benefit.

As coaches, we have a responsibility to understand those distinctions. We shouldn't sell students a false sense of security, and we shouldn't allow protective equipment to become an excuse for exposing them to more punishment than their training requires.

The best way to protect someone from an impact is not necessarily to add more padding. Sometimes it's to avoid the unnecessary impact in the first place.

That's a principle worth remembering, whether we're talking about football, rugby, boxing, kickboxing, or MMA.