I once watched an ESPN sports science segment which discussed some of the physiological demands that a NASCAR driver requires. Yet in most sports I see, speed and strength are the things that impact athletes the most, which obviously isn't an issue for a NASCAR driver.
Why do NASCAR drivers retire? What does aging change in drivers that reduces their performance?
Googling 'reaction time age driving', it seems the National Institute of Senior Health argues that
It’s your health — not your age — that matters most in driving safely.As you get older, you may notice physical changes or changes in other abilities. For example, you may have difficulty seeing at night or may not react as quickly to sudden changes. These changes can affect your driving, especially in challenging situations like merging or changing lanes.
Age-related changes that may affect driving include changes in vision, hearing, attention and reaction time, and strength, flexibility, and coordination. Medications and certain health conditions can also affect people in ways that make driving dangerous.
Age-related changes vary widely from one person to the next. That’s why some people can continue driving much longer than others.
Read the entire thing here http://nihseniorhealth.gov/olderdrivers/howhealthaffectsdriving/01.html
Now even though this is seemingly related to seniors, it'll surely apply to "anyone aging". NASCAR demands a very high level of reaction time, attention and coordination, just to repeat af few of the above, and as you get older, younger people come around to replace you.
