Short Wave - Episode Summary

Episode Title: How do extreme G-forces affect Olympic bobsledders?
Date: February 4, 2026
Host: Emily Kwong (NPR)
Guests:

• Dr. Aaliyah Snider (Former skeleton athlete, Neuropsychologist, University of Florida/UCLA)
• Dr. Peter McCarthy (Neurophysiologist, University of South Wales/Durban Institute of Technology)

Main Theme & Purpose

This episode explores the under-researched brain health risks facing Olympic bobsled and skeleton athletes—specifically the phenomena of "sled head," a cluster of cognitive, physical, and emotional symptoms caused by repeated exposure to high G-forces and vibrational impacts on the track. Host Emily Kwong guides a discussion with former elite athlete-turned-neuropsychologist Aaliyah Snider and neurophysiologist Peter McCarthy about the science behind these injuries, real-world impacts on competitors, and the emerging ideas for making sliding sports safer.

Key Discussion Points and Insights

1. The Athlete Experience: Euphoria and Danger

• Opening descriptions of bobsled, skeleton, and luge's intensity set the scene for the physical forces athletes endure (00:21–00:47).

• Aaliyah Snider details the initial thrill and latent danger:

  "To me, it felt like the closest thing you could get to flying. It was like a roller coaster that you could control. But then on the bad days, it felt like a minute of a car crash." (00:47–00:57)

• She recounts disturbing symptoms post-run—shakiness, disorientation, trouble concentrating, nausea, light sensitivity, and irritability that worsened as symptoms accumulated (00:57–01:24).

• Athletes were often told these issues were "normal" and rarely discussed them openly, fearing exclusion from competition (01:28, 02:49).

2. Sled Head: Recognizing a Hidden Issue

• Sled head encompasses dizziness, nausea, cognitive issues, and chronic brain injury—what was once an open secret or dismissed as “normal” wear and tear (01:31–01:47).
• Aaliyah Snider:

  "Oh, you know, everybody's kind of a little bit concussed all the time." (01:28–01:31)

• Lack of research and understanding made it hard for athletes or clinicians to treat or prevent these injuries; eventually, Snider suffered repeated, accumulative concussions:

  "I probably ended with around six concussions... I had to be medically retired." (01:47–02:13)

3. Why These Sports Are So Physically Extreme

• Explanation of G forces:
  • 1G = what we feel standing on Earth; bobsled/skeleton Olympic events can hit over 5Gs, comparable to roller coasters (05:03–05:59).
  • On tight curves and at high speeds, athletes’ brain tissue is forced against the skull, sometimes causing microtraumas or full concussions (05:59–06:32).
  • Helmets help, but can’t stop the brain from moving inside the skull (06:32).

4. Science Catches Up: Measuring the Risks

• Peter McCarthy discusses helmet sensors to measure vibration and acceleration, revealing just how much athletes’ heads and bodies are jerked—in some cases, the head and body move in different directions (06:56–07:30).

  "We put three axis devices inside the helmet...to tell when the head was going in one direction and the body in another." (06:56–07:10)

• Data has been presented to the International Bobsleigh and Skeleton Medical Committee, but much remains "unquantified" and under-researched (07:32–07:55).

5. The Nuanced Impacts of Sled Head

• Snider observes a spectrum of symptoms, from subtle cognitive decline to overt concussion. "Sled head" can look different from athlete to athlete, influenced by discipline, position, history, etc. (08:20–09:00).
• First traumatic brain injury or concussion may lower tolerance for subsequent brain stress; subsequent runs cause increasing sensitivity and impaired regulation of heart rate, breathing, and attention (09:02–10:28).
• The problem is cumulative:

  "Wear and tear on the accuracy and tolerability of the nervous system to stressors." (10:33–10:50)

6. Recovery Obstacles and the Push-Through Mentality

• Athletes seldom report symptoms for fear of losing their spot, and the prevailing “push through” culture discourages recovery (02:49–03:07, 11:28–12:57).

• Peter McCarthy:

  "Athletes want to compete and they will suffer to compete...so you cannot rely on anybody to do it [self-report]." (13:16–13:41)

• Need for objective monitoring; use sensors/"exposure meters" to determine when athletes should have a mandatory break (13:43–14:17).

• Aaliyah Snider:

  "The brain is always changing... We can leverage that. We can do cognitive training, we can do physiological training, we can do autonomic re-regulation training...we need to take all of that into consideration when we're rehabilitating someone. And it is possible." (11:53–13:03)

Notable Quotes & Memorable Moments

• On the emotional toll:

  "You have to think of it as a living organism that is biological, but also responds to...cognitive, emotional, physiological, behavioral [inputs]."
  (Aaliyah Snider, 12:35–12:49)

• On systemic responsibility:

  "You need to have an objective measurement...If you were to wear an exposure meter and say you've had sufficient for this week, go and have a rest, you can get higher performance...but it's recognizing and putting a structure in place to actually protect the athlete."
  (Peter McCarthy, 13:43–14:17)

• A hidden, shared experience:

  "They wouldn't tell the coaching team or the medical team for fear of being excluded from the next training day and potentially overlooked for the team."
  (Peter McCarthy, 02:49–03:07)

Important Timestamps

• 00:47 – Aaliyah Snider describes skeleton, euphoria vs. fear
• 01:08–01:28 – Snider’s symptoms post-runs; normalization of “concussed all the time”
• 02:26–02:33 – Snider decides to study neuropsychology because of her experience
• 03:07 – McCarthy on why athletes hide symptoms
• 05:03–05:59 – Explanation of G forces; comparison to roller coasters
• 06:56 – McCarthy on helmet sensor research
• 08:20 – Snider describes clinical diversity of “sledhead” symptoms
• 09:02–10:28 – Discussion of the body’s regulatory system and cumulative injuries
• 13:16 – McCarthy on why sports governing bodies need objective measurement
• 13:43–14:17 – Recommendations for athlete exposure monitoring

Conclusion & Calls for Change

• Science is still catching up with the lived experiences of bobsled and skeleton athletes, but clinical and technology advances are opening up possibilities for less damaging competition and more effective recovery.
• Both Snider and McCarthy advocate for systems—and a culture—that recognize physiological limits with objective measures (such as exposure meters), greater transparency, and nuanced, proactive medical support.
• The International Bobsleigh and Skeleton Federation did not respond to NPR’s inquiries at the time of the episode.

Overall Tone

Conversational and empathetic, with a combination of scientific rigor, personal storytelling, and calls for systemic athlete protection—balancing scientific curiosity with athlete welfare.

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