Exercise Improves Mood, Focus, Aids Memory
Dr. Wendy Suzuki’s career was going great. She earned tenure at New York University, met lots of people in her field and published exciting findings about brain plasticity. Nothing else was going great, she explained at an NIH Director’s Lecture held recently in Masur Auditorium. All she did was work.
To rebalance her life, she started to go to the gym regularly. She got in shape and her mood and focus improved dramatically. One day, Suzuki noticed that writing an NIH grant proposal was going surprisingly well. For her, grant writing had never been easy.
“When I thought a little bit more about it, I noticed that it was going well because I was able to focus my attention deeper and longer,” said Suzuki, professor of neural science and psychology at NYU. “That really got me thinking.”
Up until that point, Suzuki had studied the brain’s ability to form and retain new memories and, more specifically, the hippocampus. Resembling a sea horse, the hippocampus is a region in the brain critical to declarative memory, or the recollection of facts. Her research focus was on how the patterns of electrical activity in the hippocampus could help us form new memories for facts and events.
After her experience writing grants, she wanted to learn more about what exactly improved her memory.
“When you are a professor at an undergraduate institution and you want to learn a new topic—like the effect of exercise on the brain—the first thing you do is decide to teach a new undergraduate course on it. So I decided to develop and teach a new undergraduate class that I called ‘Can exercise change your brain?’” Suzuki said.
As she prepared for the course and reviewed literature on exercise and the brain, she discovered three things. Exercise improves mood, increases focus and stimulates neurogenesis, or the birth of neurons, in the hippocampus.
Most research on this topic, however, had only been conducted in elderly populations or in children, Suzuki said. There were no studies on young or middle-age adults or research on exercise’s effect on the hippocampus.
She decided to have her students exercise before class, then teach them about what was happening to their brains. Suzuki herself began to train physically as preparation to teach. On Sept. 7, 2009, class began.
“The level of engagement I got was transformative,” she said. “It made me really think twice about how fascinating the effect of exercise on the brain was.”
After the class, Suzuki switched her research focus. She set out to define the exercise prescription for optimal brain health depending on age, genetic background and fitness level. She also wanted to understand what exactly happens in the brain.
In one of her first experiments, she recruited healthy volunteers between ages 18 and 35 and divided them into two groups. One group rode an exercise bike for an hour while the other watched an action television show. Those who biked improved their attention. They reported an increase in the ability to focus between 30 minutes and 2 hours after they had exercised.
Suzuki is also measuring the long-term effects of exercise on the brain. In another experiment, she recruited healthy volunteers ages 13 to 59. One group rode an indoor exercise bike 3 times a week for 12 weeks. A second group played video games as the first group exercised. Before the participants began the study, Suzuki tested their cognitive ability. One cognitive test specifically measured hippocampal function.
After 3 months, she noted that bikers’ moods improved significantly when cardiovascular function improved. She also observed an increase in hippocampal function in the group that exercised compared to the group that played video games.
Studies in rodents suggest that exercise releases brain-derived neurotrophic factor. BDNF plays an important role in hippocampal neurogenesis, Suzuki noted. Researchers are studying why this is the case.
Recently, Suzuki started a pilot study with first-year students at NYU. She is observing the effects of exercising for one semester and then not exercising for another semester. She hopes to learn more about how exercise affects students’ cognitive function, study habits, drug use and academic performance.
So, what’s the ideal exercise prescription for brain health? Right now, Suzuki said, we don’t know the answer to that question. We do know that the optimal level is “something in between walking and being a triathlete,” but when we do find out, this will be one of the most effective cognitive enhancers we have today, she concluded.