Tag Archives: exercise

Walk-a-holic

Google Map directions of the 5-minute walk from the ACCENT center to Pause Café.

“It’s a 20-minute walk,” sighed my American friends, complaining that it was “too long.” It was our first week in Paris on our study abroad program, and we were planning on going to a café. After Google maps indicated that the metro stop was far from the original café, we ended up going to Pause Café. It was on the corner of the street near the ACCENT center, where our daily classes are held.

 

Image of Pause Café.

I was shocked by the lack of energy that we had. Looking around us, Parisians were walking from place to place without breaking a sweat. Walking for twenty minutes, even thirty, was typical for a Parisian. This got me thinking, how different would my life be if I lived in Paris. In Atlanta, shops and restaurants were far apart, sidewalks were narrow, and the city was difficult to explore without a car. But in Paris, everything was nearby, and sidewalks were wide. If I were to walk this much every day for the rest of my life, how would that impact my health?

Exercise is known to have many health benefits. A fact that has been ingrained in my mind since elementary school. What I knew was that exercise could prevent heart attacks and diseases, but not its effect on the brain.

Researchers show that exercise improves memory, specifically our memory of certain places and events (Cassilhas et al., 2016). The anterior hippocampus provides us with the ability to imagine our house and move around our neighborhood (Zeidman and Maguire, 2016). As we get older the hippocampus decreases in volume resulting in increased forgetfulness (Raz et al.,2005). However, there may be a way to halt those effects and possibly reverse them.

Erickson et al. (2011), reveal in their study that physical exercise improves our long-term memory, specifically our navigational memory. By exercising 3 times a week for one-year, participants had an increase in the volume of their anterior hippocampus. However, participants who did not exercise had a decreased anterior hippocampal volume. Overall, the study showed that only the decreased volume in the anterior hippocampus can be reversed with exercise, but not other parts of the hippocampus. This is a well-designed experiment because 120 participants were involved in the study, which makes the results more applicable to the general public by representing different types of people in the population. The differences in the size of the anterior hippocampus can be better observed and statistically tested with this large number of participants. Further, by testing participants prior to the exercise protocol, after 6 months, and after one year, we can look at the effects of exercise on the anterior hippocampal volume both in the short-term and long-term.

Graphs of the increase in the volume of the anterior hippocampus for the exercise group (blue line) compared to the decrease in the volume of the anterior hippocampus for the control (red line), evident in both the left hemisphere and the right hemisphere of the hippocampus.

Writing this now, I regret missing that 20-minute walk because I now know that a little exercise every day goes a long way in improving my memory. This leaves me wondering, is there a certain time frame when I should be exercising after learning new material?

Researchers performed a study to test whether there is an appropriate time to exercise after learning to improve memory recall (Van Dongen et al., 2016). Participants were assigned into three groups; those who exercised immediately, those who exercised after 4 hours and those who did not exercise. They learned to associate a certain object with a location (refer to image below).The researchers then asked the participants to recall that association. The results showed that exercising 4 hours after learning instead of immediately after enhanced participant’s ability to remember those associations compared to those who did not exercise. Hence, properly timed exercise can enhance long-term memory. The researchers strengthen their conclusion by controlling for problems that could affect the results.Such as having half the participants perform the task at 9AM, while the other half perform it at 12PM. This accounts for the differences in performance at different times of the day, which ensures that improvement in memory recall is occurring due to exercise.

Image of task protocol: associating an object with a location. The orange box represents the study phase, while the blue box represents the testing phase.

So, my elementary school teacher was right after all. Exercise is important for a healthy heart and, as it turns out, a healthy memory. Not only does this motivate me to exercise more often, but also, these studies give me hope for new intervention methods for patients with memory recall deficits. An example would be Alzheimer patients, who struggle with navigating the world (Weller et al., 2018). Another would be patients with major depressive disorder, who have memory impairments in encoding and recalling information (Gourgouvelis et al., 2017). It is cases like these that highlight the importance of understanding the impact of exercise on memory.

Now, when my friends and I have the option between using the metro or walking for 20-minutes, we choose the latter. Living in Paris for 4 weeks today, I have assimilated with the Parisian way of life. I am now able to walk in Paris for hours without the slightest soreness in my legs. It has become my new way of life.

 

References:

Cassilhas, R. C., Tufik, S., & de Mello, M. T. (2016). Physical exercise, neuroplasticity, spatial learning and memory. Cellular and Molecular Life Sciences, 73(5), 975-983.

Erickson, K. I., Voss, M. W., Prakash, R. S., Basak, C., Szabo, A., Chaddock, L., … & Wojcicki, T. R. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017-3022.

Gourgouvelis, J., Yielder, P., & Murphy, B. (2017). Exercise promotes neuroplasticity in both healthy and depressed brains: an fMRI pilot study. Neural plasticity, 2017.

Raz, N., Lindenberger, U., Rodrigue, K. M., Kennedy, K. M., Head, D., Williamson, A., … & Acker, J. D. (2005). Regional brain changes in aging healthy adults: general trends, individual differences and modifiers. Cerebral cortex, 15(11), 1676-1689.

Van Dongen, E. V., Kersten, I. H., Wagner, I. C., Morris, R. G., & Fernández, G. (2016). Physical exercise performed four hours after learning improves memory retention and increases hippocampal pattern similarity during retrieval. Current Biology, 26(13), 1722-1727.

Weller, J., & Budson, A. (2018). Current understanding of Alzheimer’s disease diagnosis and treatment. F1000Research7.

Zeidman, P., & Maguire, E. A. (2016). Anterior hippocampus: the anatomy of perception, imagination and episodic memory. Nature Reviews Neuroscience, 17(3), 173.

Walking through Paris

Amongst the many changes I have experienced while in Paris, I noticed that I am walking considerably more than I usually do. While most people are aware of the positive impact walking and exercise can have on the body, I am dedicating this post to exploring the effects of exercise on the brain.

Thanks to my handy Fitbit (yes, I know I am a little obsessed), I am able to track my daily activity, so I have a very good idea about how much exercise I am getting. Between going to class, touring museums, and exploring getting lost in the streets of Paris, I am walking an average of over 8 miles every day. Paris is a very “walk-able” city, and my friends and I regularly opt to walk to our destinations instead of using the metro. I know that this must be affecting my cognitive ability, because even while operating on 4-6 hours of sleep every night, I am able to focus and work surprisingly well.

Fitbit evidence that 1) I am walking crazy amounts in Paris, and 2) I can justify eating multiple pastries a day*  *point 2 has not been scientifically proven

Fitbit evidence that 1) I am walking crazy amounts in Paris 2) I can justify eating multiple pastries a day*
*point 2 has not been scientifically proven

A recent study in college-aged females found that after only a single session of moderate exercise, participants showed increased brain activation during a working memory task (Li et al. 2014). Working memory is a limited brain resource that temporarily stores, processes and updates action-related thinking. It is utilized when you need to actively handle information, and your working memory capacity is an important measure of cognitive function. The researchers in this study used a modified N-back task to measure working memory. This task requires participants to attend to a sequence of stimuli, and determine if the current stimulus matches a stimulus that was “N” steps earlier in the sequence. The task gets more and more difficult as N increases, because it becomes harder to keep track of when a stimulus appeared.

A visual representation of the N-back task used in the study by Li et al. (2014)

A visual representation of the N-back task used in the study by Li et al. (2014)

To compare brain function, the subjects performed this task while in a functional magnetic resonance imaging (fMRI) machine, once following exercise, and once following a rest period. The fMRI measures blood oxygenation, which provides a visual image of brain activation. While there was no significant change in subject performance on the task, the data show more brain activation in the exercise condition, especially in the prefrontal cortex (PFC) and medial occipital cortex during the 2-back condition. The PFC is well recognized to be important for working memory, and the specific areas of the occipital lobe that changed are also involved in online processing. The lack of performance change limits the conclusions that can be drawn from this study, but it is reasonable for me to assume that my working memory capacity is positively influenced by the increased exercise I get in Paris. The researchers clearly showed that exercise influenced the brain areas important for working memory in subjects of my same age and sex, and this effect would likely be enhanced by an extended exercise routine like mine. A future study could explore the effect of chronic exercise, or use multiple behavioral measures to see if that leads to more pronounced changes in working memory performance.

Working memory is not the only brain function influenced by exercise. In fact, hundreds of studies explore how exercise can change the brain. One of the most common focus areas is how exercise increases brain-derived neurotropic factor (BDNF) in the hippocampus. BDNF is very important for brain plasticity, and the hippocampus is highly involved in learning and memory. One study found that exercise enhanced memory and cognition in rats, through the action of BDNF and the pathways it influences (Vaynman, et al. 2004). A different study focused on the non-neuronal cells in the brain, called glial cells (Brockett, et al. 2015). They found that running influenced synaptic plasticity in rats, producing widespread positive effects in both neurons and glial cells in areas associated with cognitive improvement. The last study looked at showed how exercise can help people’s mental health by reducing the stress hormone cortisol, through overall regulation of the hypothalamic-pituitary (HPA) axis (Zschucke et al. 2015).

I walked almost 10 miles before stumbling upon this set at Fete de la musique, and the journey was as fun as the event!

I walked almost 10 miles before stumbling upon this set at Fete de la musique, and the journey was as fun as the event!

It is so interesting to hypothesize about the different ways that my brain may be changing in response to something as simple as walking. Evidence suggests that my working memory capacity, brain plasticity, and mental health are all influenced by exercise. Now that I only have one week left to enjoy Paris, I will make sure to walk everywhere to experience, learn and improve my brain as much as possible. With all of the positive effects Paris seems to have, I know I will be planning a return trip the second I get home!

 

References 

Brockett AT, LaMarca EA, Gould E (2015). Physical Exercise Enhances Cognitive Flexibility as Well as Astrocytic and Synaptic Markers in the Medial Prefrontal Cortex. PLoS ONE. 10(5): e0124859.

Li L, Men W-W, Chang Y-K, Fan M-X, Ji L, & Wei GX, (2014). Acute Aerobic Exercise Increases Cortical Activity during Working Memory: A Functional MRI Study in Female College Students. PLoS ONE. 9(6): e99222.

Vaynman S, Ying Z, and Gomez-Pinilla F, (2004). Hippocampal BDNF mediates the efficacy of exercise on synaptic plasticity and cognition. European Journal of Neuroscience. 20: 2580–2590.

Zschyke E, Renneberg B, Dimeo F, Wüstenberg T, & Ströhle A (2015). The stress-buffering effect of acute exercise: Evidence for HPA axis negative feedback. Psychoneuroendocrinology. 51: 414-425.

 

 

 

Sugar, Parisian Sights, and Group Runs are Nice

Bonjour family and friends,

When I first arrived in Paris two weeks ago, I was excited to find so many active Parisians running and biking everywhere! Walking around the Cité Universitaire residential campus, I am often startled by a breathless “Pardon!” (Pardon me!) as a runner passes by on my left. Also, more than 20,000 bikes are available for rent in Paris through Vélib’ for €1.70 per day (visit http://en.velib.paris.fr/How-it-works/Bikes). My Paris bucket list definitely includes trading my metro pass for a bike for at least one day in the upcoming three weeks.

Velib

Vélib’ public bicycle sharing system

One of my professors, Dr. Jacob, and our TA, Rachel, lead group runs in parks around Paris. I ran my first half marathon this past March in Atlanta and wanted to continue running and exercising while in Paris. Running is a great opportunity for sightseeing and exploring beautiful, natural spaces such as parks, gardens, and riverbanks.

park run

Rachel and I spreading our wings toward the birdhouse carvings in the tree!

Running also helps work up a healthy appetite…Lucky for me, there’s a boulangerie (bakery) on the corner of each street!

During the hour-long lunch break between my two neuroscience courses, I usually orient myself towards a boulangerie for lunch. Nearly every boulangerie’s Formule Dejeneur (or Lunch Formula) includes a sandwich, drink, and dessert that’s almost too pretty to eat. With so many boulangeries and crêpe stands as far as the eye can see, Paris must be every sugar addict’s heaven on earth. However, such easy access to desserts makes me wonder about the current diabetes rate in France. Also, I wonder in what way physical exercise, such as running and biking, can affect a diabetes patient’s brain. After some online research, I found a few neuroscience explanations to satisfy my curiosities (for now).

Formule Dejeuner

Sample lunch formula

 

Tarte au Citron

Tarte au Citron (Lemon Tart) – Is your mouth watering yet?

First of all, diabetes is a disease in which high blood sugar levels exist over a long period of time. I personally know a few individuals who are pre-diabetic and have to carefully monitor the sugars they consume. Drawing from a research study published today (6/8/2015) in The Lancet, a British medical journal, diabetes occurrence increased 45% from 1990 to 2013 (Global Burden of Disease Study 2013 Collaborators, 2015). In France, 7.2% of adults (20-79 years old) suffer from diabetes. This percentage represented about 3,241,300 diabetes cases last year in 2014 (visit https://www.idf.org/membership/eur/france).

Diabetes, specifically diabetes mellitus, directly relates to neuroscience because this disease decreases brain function and leads to neurodegenerative diseases (Yi, 2015). In a research study hot off the press (5/22/2015), Nunes de Sena et al. investigated the effect of treadmill training on the brain function of diabetic rats. They divided sixty rats into four groups, with exactly fifteen rats in each group.

  • Group one included non-trained, healthy rats.
  • Group two included trained, healthy rats.
  • Group three included non-trained, diabetic rats.
  • Group four included trained, diabetic rats.

Based on this experimental break down, half of the rats received a chemical injection (streptozotocin) that led to diabetes over the course of thirty days and symptoms of hyperglycemia and body weight loss throughout the experiment. After thirty days, the exercise (“trained”) groups underwent five weeks of running training on a treadmill apparatus.

rat on treadmill

Could you imagine seeing this runner training at the gym?

On the day after the last training session, all of the rats participated in a short-term memory test, known as the Novel Object-Recognition Test (NOR). Rats were placed at the center of an open field apparatus (a.k.a. box) and given three minutes to explore their new environment. (This acclimatization period reminds me of the first few days after our arrival in Paris. We also landed in a new environment that we needed to adjust to before beginning coursework.) After the initial three-minute exploration time interval, testing included two five-minute trials. In the first trial (T1), the researchers placed two different objects inside the testing box. In the second trial (T2) one hour later, a new object replaced one of the objects from the first trial. The objects were as different as they could be! They differed in shape, surface, color, contrast, and texture. The researchers recorded the amount of time the rats spent exploring the new object and divided by the amount of time the rats spent exploring both objects, to check for any object preference. In terms of results, both of the exercise groups exhibited a stronger preference for the novel object. Thus, the researchers concluded that treadmill running improved short-term memory performance in both healthy and diabetic rats. I am not entirely convinced, however, based on results from one memory task. In order to establish a stronger connection between running and short-term memory, I think multiple, diverse memory tasks should be carried out. Overall, this paper is significant due to a major strength in the design of the research study: for the first time, researchers used diabetic rats to show that exercise improves performance in a non-spatial memory task. I am highly interested in reading future studies regarding the effects of exercise on other components of brain function in diabetic rats! Hopefully, such studies will contribute to more naturopathic treatments for pre-diabetic and diabetic patients.

With so many picturesque gardens, parks, and the Seine River, Paris provides countless opportunities for running. Even if you have normal blood sugar levels, what are you waiting for? Explore as you run!

À bientôt,

Beatrice

References

Bill F, Foundation MG (2015) Articles Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990 – 2013 : a systematic analysis for the Global Burden of Disease Study 2013. 6736:1990–2013.

De Senna PN, Xavier LL, Bagatini PB, Saur L, Galland F, Zanotto C, Bernardi C, Nardin P, Gonçalves CA, Achaval M (2015) Physical training improves non-spatial memory, locomotor skills and the blood brain barrier in diabetic rats. Brain Res: 1–8 Available at: http://www.ncbi.nlm.nih.gov/pubmed/26032744 [Accessed June 7, 2015].

Yi SS (2015) Effects of exercise on brain functions in diabetic animal models. World J Diabetes 6:583–597 Available at: http://www.ncbi.nlm.nih.gov/pubmed/25987956 [Accessed May 21, 2015].

All images were obtained through a Google image search, besides the image of Rachel and I in the park and the image of the Tarte au Citron.