Your reaction time does more than just reveal how quickly you can respond in everyday situations; it offers valuable insights into your physical and cognitive health. How fast you react can be an indicator of brain function, cardiovascular health, and even your risk of early mortality.
As we age, it’s normal for reaction speed to decline. This explains why athletic performance tends to decrease after the age of thirty. However, maintaining a relatively quick reaction time as we grow older can be a sign that our brain is still functioning well. But reaction time tells us more than just that—it provides essential information about the health of our entire body.
Why Your Reaction Speed Matters
“Some individuals naturally react faster, even before aging becomes noticeable,” says Simon Cox, professor of brain and cognitive aging at the University of Edinburgh. “However, slower reactions often reflect age-related decline and indicate the overall health of several bodily systems.”
A Simple Test to Measure Your Reaction Time
You don’t need fancy equipment to test your reaction time. With a friend and a ruler, you can perform a simple “ruler drop test” at home:
-
Sit down and rest your forearm on a table with your wrist hanging off the edge. Position your thumb and forefinger at the edge of the table.
-
Ask your partner to hold a ruler vertically, with the “zero” mark aligned with your thumb.
-
Without warning, your partner drops the ruler, and you try to catch it as quickly as possible.
The point where you catch the ruler indicates your reaction speed. Here’s how to interpret the results:
-
Catching the ruler before 7.5 cm suggests excellent reaction time.
-
7.5–15.9 cm indicates above-average reaction time.
-
15.9–20.4 cm is average.
-
20.4 cm or more is below average.
-
Anything over 28 cm is considered poor.
Research has shown that slower reaction times are often associated with higher risks of certain diseases, including heart disease, stroke, and lung conditions. In addition, poor reaction times are linked to greater risks of falls, loss of independence, and even dementia.
The Impact of Aging on Reaction Time
Cox explains that reaction times differ based on several factors, including sex, genetics, fitness level, personality, and lifestyle. The real takeaway is not a single test result, but rather the trend over time. If your reaction times decline steadily, that’s when you should be concerned.
Your reaction time depends on how various sensory and motor systems work together. Vision, hearing, and smell all send signals to your brain, which processes the information and instructs your muscles to respond. However, as we age, each part of this process can weaken. Cox explains, “With age, the brain still recognizes the stimulus quickly, but the body reacts more slowly.”
The Role of Physical Health
Alaa Ahmed, a biomedical professor at the University of Colorado Boulder, notes that as people age, body health becomes a bigger factor in reaction speed than brain performance. Muscle fibers that help us react quickly shrink over time, and mitochondria—the energy producers in our cells—become less efficient, contributing to slower movement.
“Quick movements become more taxing as we age,” Ahmed says. “Older adults rely more on reacting faster than moving faster.”
However, research from Loughborough University shows that the brain and nervous system can still perform well in older age. Professor Matthew Pain measured how elderly participants responded to sudden noises through their ankles, and while their physical response lagged, their brains processed the signals quickly. “The raw nervous system remains quite intact,” Pain explains. “They can respond fast, but they won’t initiate movement as quickly.”
Training to Maintain Fast Reactions
You can maintain and even improve your reaction times through regular training. Online tests like the Human Benchmark Reaction Time Test are a great way to monitor changes over time. This test involves clicking when a red box turns green. Drops in performance could signal sensory or cognitive decline, with some research showing that diminishing pattern recognition can precede dementia by more than ten years.
Cox advises that staying mentally and physically active can help protect your reflexes. “Reaction drills used in sports may strengthen both the brain and the body,” he says. Mental exercises, such as playing strategy games, learning a new instrument, or playing sports, can stimulate the mind and slow cognitive aging. Additionally, activities like balancing on one leg while reciting the alphabet or walking while turning your head can help improve both physical coordination and reaction time.
“Staying mentally and socially engaged slows cognitive aging across various thinking skills,” Cox adds. This means that maintaining an active lifestyle and engaging in mental challenges can help preserve both physical and cognitive health, keeping you sharp well into older age.
Your reaction speed is more than just a measure of quick reflexes—it’s a reflection of your overall health. By understanding how reaction time changes with age, you can take steps to maintain your brain and body’s performance. Regularly monitoring your reaction times and incorporating activities that challenge both the body and mind can help keep you sharp and healthy for years to come.