How Exercise Stops Your IQ From Declining
Finding consistent motivation to exercise can be challenging. Sure, we all know exercise is good for us in many different ways and that there’s no shortage of reasons to hit the gym, but in my opinion, keeping your IQ from declining is the BEST reason to exercise that not many people know about.
The first thing to know about IQ is that it’s largely heritable, and this isn’t debated within the current body of research. It’s long been established that the genetic component of IQ hovers around 70%. The other 30% is mediated by environmental factors such as diet and other things that maximise healthy brain development in early life, like quality of education / brain stimulation (this works both ways – smart kids seek out more environmental stimulation, and more environmental stimulation creates smart kids).
The second thing to know about IQ is that it can be divided into two types, known as “fluid” or “crystallised” intelligence. Crystallised intelligence is your accumulated knowledge and experience, meaning things like general knowledge, your vocabulary and ability to do maths, etc. Your crystallised IQ improves over time as you go through life and gain more information and skills. On the other hand, your fluid intelligence is your capacity to deal with novel information. This means things like problem solving, abstract reasoning, creative visualisation and pattern recognition. The two have a dynamic relationship; fluid IQ moderates how much information you can take in and how fast you can take it in, meaning a higher fluid IQ increases your crystallised IQ. While there is theoretically no limit on how high you can take your crystallised intelligence, your fluid intelligence is on more of a what-you-were-born-with basis. Both types of IQ continue to increase up until your early 20’s, where they peak. Unfortunately, this isn’t how it stays for the rest of your life – fluid intelligence declines rapidly with age.
It all comes down to your cardiovascular system. The brain is an extremely physiologically demanding organ and needs large amounts of oxygen to function efficiently. If you stop exercising as you get older, your heart isn’t providing enough oxygen to supply your brain cells with energy to maintain and grow. Exercise also promotes the release of certain neurotransmitters and growth hormones that are crucial to the brain’s overall health, contributing to better concentration and memory.
A combination of cardio and weight lifting exercise a few days per week can forestall that IQ decline as you get older – who can think of a better reason to workout?