Assets of Exercise
Highlights from the International Society for Bipolar Disorders Conference Posters and Presentations, Chicago, June 22-25, 2023
Ben Goldstein of the University of Toronto gave a plenary talk on the benefits of exercise.
He found poor aerobic fitness in 19 of 20 young bipolar patients. They had low cerebral blood flow in proportion to the severity of their exhaustion after exercise. He noted the importance of stressing an endpoint of fitness for exercise rather than weight loss. Using an exercise coach and running with family and friends was helpful in motivating patients for consistent exercise.
6 Minutes of Intense Cycling Produces Major Increases in BDNF
Brain derived neurotrophic factor (BDNF) is necessary for new synapses and call survival. A new study in J. Physiology (2023) reports that the increases in BDNF from short intense cycling exercise are much greater than from prolonged (90-minute) light cycling. The authors think that this is cause by the increases in lactate produced which helps up regulate BDNF production. This could be good for fighting depression and Alzheimer’s disease, where BDNF levels are low.
Bottom line: If you don’t have much time, bust your buns.
Participation in Sports May Mitigate Genetic Risk for ADHD in School-Aged Children
At the 2021 meeting of the Society of Biological Psychiatry, researcher Keiko Kunitoki and colleagues reported that participation in sports decreased behavior abnormalities in 9- and 10-year-old children at genetic risk for attention deficit hyperactivity disorder (ADHD). Sports were associated with greater hippocampal volume, which was associated with fewer behavioral abnormalities. Kunitoki and colleagues concluded that “participation in team sports mitigated genomic risk for psychopathology at age 9–10 in part through increased hippocampal volume.”
Editor’s Note: These data are consistent with a program called the Vermont Family-Based Approach developed by researcher James Hudziak, who heads the Vermont Center for Children, Youth and Families at the University of Vermont. The program encourages families to practice different domains of wellness, such as music, mindfulness, exercise, and nutrition, among others. The idea is to support emotional and behavioral health, and to do so intensively in families where children show signs of mood and behavioral difficulties or are at risk for these difficulties.
Hudziak analyzed brain scans of 232 children aged 6 to 18 and reported that “practicing an instrument such as the piano or violin increased working memory, gray matter volume in the brain, and the ability to screen out irrelevant noise. Practicing mindfulness increased white matter volume and reduced anxiety and depression. Exercise also increased brain volume and neuropsychological abilities.”
In 2015, researcher Benjamin I. Goldstein reported that 20 minutes of vigorous exercise on a bike improved cognition and decreased hyperactivity in the medial prefrontal cortex in adolescents with and without bipolar disorder, and researcher Danella M. Hafeman reported that offspring of parents with bipolar disorder who exercised more had lower levels of anxiety.
To summarize, engaging in exercise, team sports, music, and meditation/mindfulness are beneficial for all children, and can be especially helpful for those at risk for depression or bipolar disorder. Children who are already symptomatic should additionally be offered something like family focused therapy (FFT), a multi-faceted approach developed by researcher David Miklowitz, in which families of young people at risk for bipolar disorder take part in therapy, learning together about the illness and practicing strategies for communication and coping.
Positive Effects of a Brief Session of Aerobic Exercise for Sedentary Children
At a symposium at the 2019 meeting of the American Academy of Child and Adolescent Psychiatry, researcher Benjamin I. Goldstein reported that a single 20-minute session of aerobic exercise (achieving 70% of maximal heart rate) was associated with improvement in cognition and in abnormalities seen on brain imaging in young people. Goldstein urged clinicians to do motivational interviews with sedentary children in their care, emphasizing the positive cardiovascular and cognitive effects of exercise. He indicated this would be more effective than a focus only on weight loss, which is much more difficult to achieve.
Exercise May Protect Against Breast Cancer
Epidemiological evidence suggests that exercise reduces breast cancer rates and rates of breast cancer recurrence. However, it is not well understood why this is true.
Exercise that is intense enough to increase the heartrate and induce heavy breathing can increase the hormone epinephrine in the blood. A 2017 article by researcher Christine Dethlefson and colleagues in the journal Cancer Research reported that this elevated level of epinephrine in the blood of breast cancer patients after one intense exercise session stopped their breast cancer cells from growing in vitro and reduced tumor growth by half.
Senior author Pernille Hojman told Reuters that while exercise could not be expected to replace anti-cancer treatments, it is a great supportive strategy that has the added benefits of increasing patients’ quality of life and sense of empowerment.
The study looked at human breast cancer tumor cells in test tubes, and the same type of tumor cells implanted into mice. Only 45 percent of the mice implanted with the cancer cells collected after vigorous exercise developed tumors, compared to 90 percent of the mice who received cancer cells collected before exercise or with no exercise.
Exercise May Improve Memory
A recent study suggests that exercising vigorously 20 minutes per day may improve “interference memory,” a type of memory that involves reconciling new learning with information one already knows. (Sometimes older information “interferes” with new learning.) In a 2017 article in the Journal of Cognitive Neuroscience, researcher Jennifer Heisz and colleagues report that performance on a high-interference memory task improved when participants engaged in 20-minute daily sessions of interval training for six weeks.
Heisz and colleagues compared three groups of students: one did interval training, another did both interval training and cognitive training, and a control group did no special training. Both exercise groups performed better on the high-interference memory task than the control group. Those who exercised also had higher levels of brain-derived neurotrophic factor (BDNF), which promotes the growth of new synapses and is crucial for long-term memory.
The researchers suggest that this finding could be useful to seniors facing memory deficits, since only six weeks of exercise improved memory performance. Interference memory tends to decline with age.
Previous research has linked aerobic exercise to better academic performance.
Exercise in Childhood Decreases Depression Symptoms Two Years Later
A 2017 study in the journal Pediatrics found that higher rates of moderate to vigorous physical activity at ages six and eight was linked to fewer symptoms of depression at age 10.
The study included 795 six-year-olds who were tracked for four years. Their physical activity was measured by accelerometry, the same type of technology found in smartphones and other consumer products that can track a person’s daily steps. Depression symptoms were assessed via interviews with the children and their parents.
While exercise seemed to reduce depression symptoms, sedentary behavior did not predict later depression.
Even Light Exercise Prevents Future Depressions
A 2017 article in The American Journal of Psychiatry suggests that regular leisure-time exercise of any intensity can protect against future depressions.
The study by Samuel B. Harvey and colleagues followed a group of 33,908 healthy adults for 11 years. The researchers found a link between regular leisure-time exercise and reduced incidence of future depression (but not anxiety). This link occurred regardless of the intensity of the exercise, and most of the effect occurred at low levels of exercise. Analysis suggested that 12% of future cases of depression could be prevented if all participants fit one hour of physical activity into their week.
A small part of the benefit came from the social and physical health benefits of exercise.
Harvey and colleagues suggested that from a public health perspective, increasing population levels of exercise modestly could lead to a substantial decrease in depressions.
Editor’s Note: Alongside maintenance treatment, in the form of antidepressants for unipolar depression or mood stabilizers and atypical antipsychotics for bipolar disorder, exercise could provide some benefits in preventing future depressions.
Tart Cherry Juice Improved Recovery from Exercise in Soccer Players
A recent study found that tart cherry juice helped soccer players recover after muscle-damaging exercise better than a placebo.
The 16 athletes in the study were randomly assigned to receive either a Montmorency tart cherry concentrate mixed with water twice a day for four days prior to and three days following exercise, or a drink with the same number of calories but less than 5% fruit content on the same schedule.
The semiprofessional male soccer players (aged 21 to 29) showed better performance on sprints, jumps, and agility tests; less inflammation; and less muscle soreness when taking tart cherry juice compared to the placebo drink.
Editor’s Note: Tart cherry juice is rich in polyphenols, chemicals found in plants with anti-oxidant effects. The juice also has melatonin-like effects, improving sleep in people with insomnia.
In Rats, Mother’s Exercise Habits Affect Those of Offspring
A recent study suggests that when a mother rat exercises during pregnancy, her offspring will exercise more too.
In the study, published by Jesse D. Eclarinel and colleagues in The FASEB Journal, pregnant mother rats were placed in cages that each contained an exercise wheel. One group had access to a working wheel on which they could run. The other group had the same wheel, but it was locked so that they couldn’t use it for running. Daughters of the rats who ran during pregnancy ran more in adulthood (both at 60 days and 300 days after birth) than daughters of the rats who couldn’t run during pregnancy.
While it is a mystery why this occurs, it is consistent with other data about the ways that a parent’s experiences can influence the next generation, even when the offspring don’t grow up with the parents.
For example, father rats conditioned to associate a specific smell with fear of an electric shock have offspring that also fear that smell (but not other smells).
Drug use is another example. Father rats given access to cocaine have offspring that are less interested in cocaine. Interestingly, father rats exposed to marijuana have offspring that are more interested in opiates.
Experiences with drugs or stress are thought to affect the next generation via ‘epigenetic’ marks on ova or sperm. These marks change the way DNA is packaged, with long-lasting effects on behavior and chemistry. Most marks from a mother’s or father’s experiences are erased at the time of conception, but some persist and affect the next generation.
The nature versus nurture debate is getting more and more complicated. Parents can influence offspring in a number of ways: 1) genetics; 2) epigenetics in the absence of contact between parent and offspring after birth; 3) epigenetic effects of behavioral contact—that is, parents’ caring and warmth versus abuse and neglect can affect offspring’s DNA expression too. All these are in addition to any purely behavioral influence a parent may have on their offspring via discipline, teaching, being a role model, etc.
Editor’s Note: The moral of the story is, choose your parents wisely, or behave wisely if you yourself become a parent.
