Fertilizer for Your Brain
We know that one way to keep our brains healthy and limber as we age is to learn something new. We can take up tango dancing or the subtle intricacies of making chocolate souffle, but the process of learning does not get easier as we get older. Our brains simply are not as malleable and they were when we were, say, 5 years old. Exciting science is emerging that shows how we can create an environment ripe for learning, in our own brains.
Until the final years of last century, the thought among scientists was that at a certain point in our lives, our brains stopped growing. Common thought was that we were born with a certain amount of neurons (brain cells) and that was it for us. However, this thinking was turned upside down in 1998 when a study was published in Nature Medicine that showed under certain conditions, parts of our brain can create new connections, grow new neurons, and repair itself.
One of these conditions is exercise, aerobic exercise in particular. The most exciting substance that has been found in relation to brain growth is called BDNF (brain derived neurotrophic factor). Essentially, it hangs out in the spaces between the neurons, and is released en masse when we jack up our heart rate. John Ratey, a professor of Psychiatry at Harvard medical school calls BDNF ‘miracle gro for the brain’ due to it’s ability to ‘fertilize’, initiate, and amplify connections in the brain.
Increased neural connections in the brain is what happens when we learn something new. When these connections are amplified in our brain, what we are learning starts to feel easier, less like work, and more fun and familiar; we don’t have to think about it as much because those connections are already formed.
Recently, studies have looked at what type of exercise most effectively raises BDNF. A study in the Journal of Sports Science and Medicine showed that the most effective way to increase base levels of BDNF is high intensity aerobic exercise. Moderate exercise can temporarily increase levels, especially if done over a longer period of time, (specifically, walking 30 minutes per day for 5 weeks), but it’s the shorter, more intense exercise sessions that show the most benefit in getting those levels up for the long term. Increasing baseline levels is what we want, because having to rely on taking a 30 minute walk immediately prior to any type of learning challenge is not the most convenient idea.
So, how we do make higher intensity exercise safe for the aging body?
Check with your doctor. Higher intensity training challenges all your muscles, including your heart. Be sure your doctor gives you the go-ahead to push yourself a little harder.
Warm up. To decrease your chances of injury, start with a warm up, something similar to what you will be doing during your workout. This gives your body a chance to get more blood moving to your muscles, it can also get your joints moving, and facilitate your range of motion.
Increase speed or intensity. When biking, pedal faster or turn up the dial. If you’re walking, try jogging, or find a hill to hike up. Do one or the other to increase the intensity of your workout. Slowly increase your capacity and you’ll get the benefits without hurting yourself.
Keeping your body and your brain active and engaged will raise the quality of your life throughout the years. When one activity can help achieve both goals, it’s worth a try.