Best to be cautious. Between amateur boxing (and know some pro boxers and former world champs), cycling (crashed a few times), and health care, seeing patients and family with concussions... it's a good thing to avoid.

The worst I've seen recently occurred at a casual group ride about three years ago. A fellow nicked the uneven pavement ledge on a notoriously uneven, irregular boulevard paved with large sheets of striated concrete -- the kind of stuff that's notorious for heaving along with the soil, creating ledges that can be nearly invisible amid the sea of light grey pavement. Poor fellow fell to the right, smacking his head hard, then slid another 10 yards or so headfirst into a curb. Fortunately the curb was sloped, slightly reducing the potential second impact. I caught the entire mess on video and it was terrifying to watch later.

Another rider and I were first to reach him, and fortunately this large group ride was accompanied by the fire department paramedics or EMTs, who quickly arrived via a golf cart sorta vehicle. While I was observing the fellow who crashed was reasonably coherent for a few moments, then lapsed into shock and began repeating the same few phrases every 15-30 seconds. His helmet was destroyed but there was no apparent scalp injury, blood, etc.

I heard second or third hand that he recovered, but never heard any details. I've noticed often when people talk about "recovery" from a concussion or head injury, they gloss over the long-term effects, perhaps to avoid embarrassing anyone. But I've seen family and friends suffer long-term consequences from concussions and TBIs, and wouldn't ever say they were "okay."

Others, like former heavyweight champ George Foreman, seemed to keep chugging along just fine despite some blows to the head that would paralyze most ordinary humans. I quit boxing in my early 20s, yet saw the long-term psychological effects on some boxers I'd known since they were teenagers in the amateurs, and later world champs. It was a permanent, daily struggle for many of them. Some have struggled with depression, alcoholism, substance abuse, behavioral problems and violence, with some jail time or mandatory confinement for mental health treatment. Much as I still enjoy the sport of boxing, it's difficult to ignore the serious cost to many participants.

My worst head blow probably came from a car wreck about 20 years ago. Broke my back and neck in six places, and I had a concussion, but never lost consciousness and retained a perfect memory of the event. But later I had severe headaches, vomiting and felt pretty lousy for a couple of weeks. Since then I've avoided most risky activities, although I've crashed my bike unassisted a couple of times and was hit by a car in 2018. Minor knocks to the helmet in the car incident. No head problems but it did worsen my neck pain and caused a pretty serious shoulder injury. I may just be lucky to have a head that isn't particularly sensitive to concussions. My mom was very sensitive to concussions, even without direct impact to the skull. And my brother, also an amateur boxer and much more talented than I, had what's called a glass jaw and was knocked down and out easily. I'm not sure he suffered any long-term consequences, as he died in a car wreck at age 40. But he always seemed okay whenever I saw him after he quit boxing in his early 20s.

It's tricky because some folks seem almost impervious to side effects from head knocks, while others are permanently impaired after a single concussion or TBI. But I prefer to err on the side of caution and not assume that folks can just brush it off and walk it off after a blow to the head.

Anyway, take care of yourself. Ask family or friends to keep an eye on you and let you know if anything seems amiss. Often victims of head injuries will be dismissive of concerns expressed by family and friends. Unfortunately that may have contributed to the death of actress Natasha Richardson. She fell while skiing, was under-diagnosed by emergency techs, and assured family she was okay despite symptoms of concussion or worse -- notably a severe headache. She died soon after from a brain bleed.