How exercise affects brain cells
Did you miss Part 1? Read it here.
The structure of the hippocampus, an area of the brain closely linked to memory and learning, is especially receptive to developing new neurons (nerve cells) in response to endurance exercise. This is because exercise stimulates the production of a protein known as FNDC5 that is released into the bloodstream during vigorous activity. Over time, FNDC5 stimulates the production of another protein in the brain called Brain Derived Neurotrophic Factor (BDNF). This protein in turns stimulates the growth of new nerves and synapses (the points of connection between nerves) as well as preserving existing brain cells.
Use it or lose it
Just as the muscles respond to a good workout by pumping up and growing, so does the brain respond to exercise by growing its neural pathways. Beginning in our late 20s, the brain’s hippocampus begins to shrink—at a rate of close to one per cent every year. By the time we reach our 60s, assuming we don’t exercise, the hippocampus will have lost over one third of its volume.
For many decades, scientists and doctors believed that we are born with a certain number of brain cells and that, as these cells died off, our brains had to make do with those remaining. This belief changed in the 1990s when research following autopsies showed new neurons within the brains of many subjects. These were particularly plentiful in the region of the hippocampus.
Another study, completed in 2010, suggests that even moderate exercise can positively affect the hippocampus. In this study, a group of researchers from various US universities, took 120 men and women in their 60s, and assigned them to one of two groups. One group walked around a track for up to 40 minutes, three times a week, while the others did stretching and toning exercises, including yoga.
Brain scans taken a year later showed that the walkers had expansion in the hippocampus, enough to offset that caused by normal aging. In the other group, the hippocampus shrunk by one to two per cent. Both groups experienced improvement in spatial memory (which helps us to do things like navigate traffic and know our way around a mall), but the walkers showed more improvement than the stretchers.
More brain benefits
Physical activity benefits the brain in ways other than stimulating new neuron growth. An increase in the brain’s oxygen levels as a result of an aerobic workout affects the brain on multiple fronts. It increases heart rate, which pumps more oxygen to the brain, and also results in the release of hormones that nurture and provide an enriched environment for the growth of brain cells. A study conducted by the Department of Exercise Science at the University of Georgia showed that even brief bouts of exercise lasting 20 minutes increases information processing and memory functions.
Furthermore, the so-called “runner’s high” that results from a sustained aerobic workout, helps reduce stress levels. For a long time, this feeling of euphoria was believed due to the release of feel-good chemicals called endorphins within the brain.
However, studies where runners had their endorphin release chemically blocked, put this theory to rest when the participants continued to experience a sense of extreme wellbeing following an intense workout. The researchers concluded that more likely the cause of the “high” is the body’s secretion of substances called endo-cannabinoids, which are similar to the active ingredient in marijuana (cannabis).
Challenging the brain
Learning a new computer program, a different language, musical instrument or a new skill will result in new neural networks that freshly- created neurons will connect to. But you can also challenge your brain in little ways every day.
Daily ways to improve brainpower include the following:
- Test your memory: Visit a local site of interest such as an art gallery or bird sanctuary, and take a guided tour. After your return, sit down and try to list all the things you learned. Memory activities that engage different levels of brain operation— taking in, remembering and recalling—help to improve brain-functioning and reduce its rate of decline.
- Go left for a day: If you are right-handed, spend the day doing everything you’d normally do with the left hand instead. (Reverse this if you are left-handed.) Start with brushing your teeth and hair, and make sure you write only with your non-dominant hand. Your brain will create new pathways to adapt to this challenge.
- Block it: Similar to the above exercise, try blocking off one of your senses (but make sure you are safe while doing so). Tidy your desk or eat while blindfolded, or listen to music with earplugs in place and feel the vibration.
- Step it up a notch: If you enjoy crosswords, knitting, or other pursuits that keep your mind engaged, keep pushing the envelope. Change to a cryptic crossword or learn a new and complicated stitch. Keep pushing, and your brain will grow with every effort.
- Try to recall: You’ve made out your shopping list and you’re all set to go but, instead of consulting your list, try recalling it. Again, you’ll be testing and strengthening your memory.
- Go upside down: Try reading upside down beginning with the morning paper and progressing through the day with textbooks and reports. Your brain will build new pathways to accommodate this new way of seeing words.
- Get enough sleep: Studies show that people who sleep between 7 and 9 hours perform better on cognitive and memory tests.