Tag Archives: runner’s high

The Good, the Bad, and the Smelly: Which Odor Will You Notice?

On any given day in Paris, I’m hit with so many different odors. The wet grass smell mixed with morning breeze greets me as I exit my dormitory. The man standing outside the door however snatches this pleasant nature aroma from my nose, masking it with copious layers of cologne. As I make my way to the RER, the stench of urine overpowers my senses forcing me to run down the stairs to catch the train even faster. And once on the train, I realize that perhaps the French sweat more than the average human being, because boy, oh boy, is that body odor game strong (I merely postulate – no scientific data supports such an outrageous presumption). As I step out of the Metro and onto the stairs rising up towards Bastille, the stench of last night’s garbage quickly hits me in the face.

Figure 1: The debris on the steps of the Opera Bastille on a Monday Morning.

Figure 1: The debris on the steps of the Opera Bastille on a Monday Morning.

The odor of the musty water thrown on the stairs by the sanitation department clashes with the spills of beer along those stairs underneath the Opera Bastille.

As I continue to make my way onto Rue de Faubourg Saint-Antoine, I realize that no matter the time of day, a good number of Parisians will always be smoking a cigarette somewhere. Fortunately, the aromas of baguettes and café au laits begin to swirl around me as I step into a local boulangerie (bakery). My nose feels at ease even if it’s just for a moment.

Figure 2: A local boulangerie near the Opera Bastille.

Figure 2: A local boulangerie near the Opera Bastille.

But let’s say I woke up at 9:06AM and class begins at 10:00AM, and not only does Dr. Shreckengost start on time, but he forces us tardy ones to pay penance by bringing French goodies the next day – aka, I want to get to class on time.

I leave my room at 9:20AM (should have left ten minutes ago), and of course this is the one-day that the tram’s ETA is 7 minutes (instead of in it’s normal 2 minute intervals), the RER is especially slow today, and all of the escalators at Chatel-Les Halles have broken down. Anything that could have gone wrong has and I emerge from the Bastille Metro stop at 9:55AM. The normal walking time from Bastille to class takes a solid 7-8 minutes. Like any other normal human being, I bolt across Rue de Faubourg Saint-Antoine sporting sandals and a bouncing backpack. I arrive panting and sweating at 9:59AM. That’s pretty clutch, I’d say.

Figure 3: Rue de Faubourg Saint-Antoine.

Figure 3: Rue de Faubourg Saint-Antoine.

So what’s the point? You’re probably thinking, “Well that’s cool Reema, nobody cares if you got to class on time (except for maybe you and Dr. Shreckengost)”. Hold your horses – there’s always a point to Reema Stories!

The difference is that when I was stressed and pressed to get to class on time, I did not notice the morning breeze or the aromas of the boulangerie (probably because I didn’t actually go inside one). What I did smell was the smoke from all the cigarettes people were smoking that morning. All I could think about was the detrimental effects of the smoke in my lungs and how these effects would slow my running speed down (not that the immediate inhalation of cigarette smoke was going to immediately affect my respiration at the time, but I didn’t think about the logistics while I was running). The only smells amplified that late morning included harmful or fear inducing odors(I don’t want to die from second-hand cigarette smoke).

I wonder why that it is…

Turns out, I’m not the only one who is extra sensitive to particular odors when I’m under stress. In fact, in some extreme cases of anxiety-related disorder, people are super-sensitive to smells associated with traumatic events in their lives.

In a recent study, Cortese et al. lookeds at the different sensitivity of odors in patients with post-traumatic stress disorder (PTSD). PTSD is a mental health condition triggered by terrifying events, whether those events were experienced or witnessed. Patients with PTSD may experience flashbacks, nightmares, and anxiety from thinking about those traumatic experiences. Many PTSD patients report trauma-related odors are particularly potent reminders of these events. A trauma-related odor might mean the smell of burning to a house fire victim or the smell of bombshells in Iraq or Afghanistan to a war veteran. There’s been increasing evidence and research that odors elicit psychological arousal and retrieval of autobiographical memories PTSD patients (Chu and Downes, 2002). Differential Odor Sensitivity in PTSD: Implications for treatment and future research is one of the first sets of studies of a long-term research plan by Cortese et al. where they looked at the behavioral responses to a range of odors with different qualities (traumatic and non-traumatic) in combat veterans with PTSD, veterans without PTSD, and healthy controls. Particularly, they examined the difference in proportion of individuals reporting distress to different categories of odors, specific individual odors, and the specific hedonic (pleasant vs. unpleasant) valence of such odors.

Figure 4: Buzz words to PTSD.

Figure 4: Buzz words to PTSD.

Cortese et al. found that the olfactory system plays a significant role in the identification of biological threats. The researchers saw that combat veterans, as compared to control subjects, had decreased responses to a large number of odors across various categories and hedonic valence. Cortese et al. believe that hyposmia (a decreased ability to detect and smell odors) may explain some of the decrease in susceptibility of positive valence odors. More so, the experimenters found that combat veterans learned to ignore non-life-threatening “distractor” odors (i.e., garbage, feces, raw sewage) and concentrate on life-threatening odors. Previous studies have shown there to be an association between stress-related disorders and attentional bias toward threat (Bryant and Harvey, 1995; Cisler and Koster, 2010).

Cortese et al.’s study is very important to the field of olfaction, to the field of psychology in which PTSD is studied, and to our country’s veterans. Experimenters analyze a detailed list of odors that affect combat veterans – a type of experimentation that had previously never been done before. However, the researchers don’t actively study this “attention bias” that they claim combat veterans may be exhibiting. The experimenters don’t actively conduct any attentional bias surveying and although data may seem to support previous research on attentional bias, it’s a bit of stretch to predict that there’s a correlation.

While my stressful sprints to class do not closely relate in magnitude to the severity of PTSD that troops go through, I find it interesting to know what odors I detect and what odors I ignore depending on what I’m doing and the mood I’m in.

Maybe I’ll notice every odor on my relaxed plane ride home? Only one way to find out!


Work Cited:

Bryant RA, Harvey AG (1995) Processing threatening information in posttraumatic stress disorder. J Abnorm Psychol 104:537-541.

Cisler JM, Koster EH (2010) Mechanisms of attentional biases towards threat in anxiety disorders: an integrative review. Clin Psychol Rev 30:203-216.

Chu S, Downes JJ (2002) Proust nose best: odors are better cues of autobiographical memory. Mem Cognit 30:511-518.

Cortese BM, Leslie K, Uhde T (2015) Differential odor sensitivity in PTSD: Implications for treatment and future research. J Affective Disorders 179:23-30.


An All-Natural High: Running through Paris

Bonjour tout le monde!

As my second week in Paris comes to a close, I can’t help but reflect on my time in Paris thus far. Have I accomplished what I’ve wanted to accomplish? Have I met my goals?

One major goal that I set out to fulfill during my time in Paris was to keep running. But before I delve into that, let me give you a little background on my relationship with running.

I never used to enjoy running. In fact, I strongly disliked running. My parents have always been big runners and have run marathons, done triathlons, Tough Mudder-type events, and many others. I could never understand why they would put themselves through the grueling process of burning up your lungs and muscles until you just couldn’t do it anymore. Why subject your body to that much pain? All throughout middle school and high school, the only running I did was on the soccer field or on the volleyball court. But that all changed this past semester.

I can’t tell you for sure what it was that changed my mind about running. To be honest, I think it might’ve been that I wanted to get in shape and I knew running would get me there. So I started running. Every other day, every few days… whenever I found time in my busy Emory schedule to run, I ran. And it got easier each time. I didn’t feel as fatigued when I ran, and the thought of running didn’t incur feelings of immense hatred anymore. I actually started to enjoy it… even look forward to it! You’re now reading the blog post of a girl who is signed up to run a half marathon in the fall, and I couldn’t be more excited about training for it.

While I haven’t had much time to run in Paris between classes, excursions, and exploring, I’ve tried to fit it into my schedule as much as I can, even if it’s  just a short, 2 mile run. The first time I went for a run in Paris, I immediately felt better and had an immediate rush of familiar excitement. As I set off to run in one of my favorite places in Paris, the Touileries garden, pounding along to the beat of “‘Till I Collapse” by Eminem, I finally identified the feeling. It was an all-natural, all-encompassing high.


Beginning my run in the Touileries (photographed by Joy Lee)

As I entered the park and continued along the path, feeling great, I wondered what caused this high, and how it affected my running performance.

So I came back to my room later that day and did a little bit of research. I found a study from 2008 that described the phenomenon I was experiencing, called “the runner’s high”. This study by Boecker et al. (2008) looked at ten athletes at two time intervals: one after 2 hours of endurance running and one during a rest period. The researchers looked at whether particular opioid receptors (molecules of tissue that bind substances called endorphins that give us a boost when we run) get depleted when we run long distances, and they indeed found that certain areas of the brain do in fact have reduced opioid receptor availability in subjects during endurance running as compared to when subjects were resting!

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Reduction in opioid receptor availability in certain areas of the brain after long distance running compared to when resting

So basically, when we run long distances, we do in fact feel an all-natural “high”, in addition to having pain-relieving symptoms — even though it often feels like we’re about to die when we’ve run for too long (Boecker et al., 2008).

This analgesic effect got me thinking though: what about when we’re extremely fatigued? We don’t seem to feel this pain-killing effect anymore: in fact, the pain is almost unbearable when we feel like we’ve reached our limit. The concept of limits reminded me of a Radiolab podcast that I had listened to while taking Human Physiology with Dr. Cafferty, fall semester 2014. In the beginning of the podcast, Jad Abumrad and Robert Krulwich (the hosts of Radiolab) introduce Julie Moss, who discusses her first Ironman experience. If you watch her running toward the finish line on YouTube, you can see how the fatigue after swimming 2.4 miles, biking 112 miles, and finally a marathon (26.2 miles) truly catches up to her.

Krulwich and Abumrad then go on to introduce what is known as the central governor theory, along with the help of physiologist Dr. David Jones. This theory describes how fatigue may in fact not be a result of muscles running out of energy: in fact, it may be more mental than we think. When we’re running low on energy, this central governor signals triggers of pain to try to get us to rest. Scientists are finding that this governor circuit is conservative, keeping a reservoir of energy readily available in case of an emergency. While some scientists argue that fatigue is one of the greatest imperfections of the body, Noakes (2012) references an Italian physiologist A. Mosso who says that fatigue may in fact be one of of our most marvelous perfections. As Krulwich jokes in the Radiolab podcast, perhaps fatigue is our body’s “almost out of gas” message, telling us we’re running out of energy when we still have a 1/4 of a tank left.

As I continue to train and eventually complete the half marathon in the fall, I know I’ll be thinking about my central governor and hoping for that endorphin boost; especially as I (hopefully) run toward that finish line, trying to avoid pulling a Julie Moss, running to the melody of Chariots of Fire.


Selfie of me while running in Montsouris park!

Until next time,



Abumrad J, Krulwich R. Limits of the Body. RadioLab. http://www.radiolab.org/story/91710-limits-of-the-body/

Boecker H, Sprenger T, Spilker, M, Henriksen G, Koppenhoefer M, Wagner, KJ, Valet M, Berthele A, Tolle T (2008). The Runner’s High: Opioidergic Mechanisms in the Human Brain. Cerebral Cortex 18: 2523-2531.

Noakes T (2012). Fatigue is a Brain-Derived Emotion that Regulates the Exercise Behavior to Ensure the Protection of Whole Body Homeostasis. Front Physiol. 3:82.