Athletes and Inflammation – when is it too much?

The gut is an often overlooked part of the body that regulates inflammation. Athletes training with heavy loads are at an increased risk for infection, which requires them to pay greater attention to nutritional strategies used to mediate inflammation. This recovery should include probiotics, which have demonstrated to be a promising nutritional intervention to control and alleviate inflammation.  

Before reading this blog, check out Immunity and Worldwide Competition because it explains how probiotics strengthen immunity and gut health, which will help you understand this blog’s discussion of probiotics and inflammation. 

In this blog, we will explain: 
The process of inflammation

The association between exercise and inflammation

How probiotics regulate inflammation

Probiotics and their effect on exercise-induced airway inflammation and infection


Inflammation is a protective reaction by the body in response to an injury or infection. It results in increased blood flow to the problematic area (redness), increased body temperature (heat), fluid accumulation and pain (caused by the release of chemicals from damaged cells). 

For athletes, exercise-induced muscle damage accompanied with inflammation may first come to mind when thinking about inflammation in general. This acute muscle inflammation from intense or prolonged training occurs when muscles undergo small micro-tears (i.e., small injuries) that cause an acute inflammatory response. Acute inflammation is not a serious problem, and the body repairs this following a workout. It is actually thought to be a part of the normal adaptation to exercise. 

It is the underemphasized chronic inflammation in the gut that may disrupt normal body functions and impair adaptations to exercise. Chronic inflammation results from stressors (e.g., heavy training, poor quality sleep, alcohol, unhealthful diet, etc.) and poor recovery from intensive training – in turn, overtraining. Poor gut health can lead to inflammation in the body, and probiotics are a recovery tool that may mitigate the negative effects of chronic inflammation and reduce the risk of overtraining. 

Exercise & Inflammation

Endurance exercise impacts inflammation throughout the body. Intense training causes acute inflammation, which is comparable to what results in patients with sepsis (i.e., inflammation throughout the body when the body releases chemicals to fight an infection) and trauma. Strenuous exercise increases the amount of pro-inflammatory cytokines, such as TNF-alpha, IL-1, IL-6, TNF receptors and anti-inflammatory modulators such as IL-10 and IL-8. 

Endurance exercise reduces the flow of blood, oxygen and nutrients to the gut, increases the permeability of the gut wall and lowers the thickness of the gut mucosal layer, which results in an inflammatory immune response – “leaky gut.” This is why the mucosal immune system has an important function – to control responses to antigens, which will control inflammation. 

The inflammatory responses generated from intense exercise are fought by gut microbiota and their short-chain fatty acids (see below) that reduce gut permeability and stop the release of inflammatory cytokines. It is suggested that the anti-inflammatory effects of gut microbiota may help delay fatigue during endurance exercise. 

Exercise-Induced Airway Inflammation

One of the consequences of prolonged inflammation is impairment of the immune system. Upper respiratory tract infections (URTIs) (e.g., the common cold and inflammation of the trachea and larynx) are common among highly trained and elite athletes because they are more susceptible to weakened immune systems. The causes of URTIs are considered unclear, but most are caused by viral infections and inhaled allergens. Airway inflammation has been reported not only after intense exercise, but also during resting among endurance athletes, swimmers and cross-country skiers.

Some studies were not able to identify pathogens causing a URTI. The unidentified URTIs were reported as being shorter in duration and lower in severity compared to infectious URTIs. As a result of the high amount of assessments that had an ‘unidentified’ cause, this led to the exploration of inflammation not associated with infection among athletes. 

Similar symptoms (e.g., sore throat, fatigue, headache, runny nose, etc.) of URTIs can also be the result of inflammation caused by inhaling cold, dry or polluted air (i.e., climate conditions), stress on the airways or dehydration, which occur because of the decrease in the integrity of the respiratory cell membranes. 

Numerous studies have reported aeroallergen sensitivity in 20-40% of athletes, which resulted in allergic rhinoconjunctivitis (i.e., a condition with nasal congestion, runny nose, post-nasal drip, sneezing, red eyes and/or itchy nose/eyes). Other studies found a 40-50% prevalence of allergic rhinoconjunctivitis among Olympic athletes.

There is a link between training volume and risk of respiratory illness. Training at a high intensity and/or high volume increases susceptibility to infection because of changes in immunity, which include a decrease in salivary IgA and an increase in pro-inflammatory cytokines.

Salivary IgA concentration or excretion rate is used to evaluate the effect of exercise on mucosal protection and associations with URTIs. An increased risk for URTIs for elite athletes is associated with low levels of salivary IgA and/or excretion rates, low pre-season salivary IgA levels and decreasing levels over training. It is suggested that probiotics help increase saliva IgA levels.

URTIs are prevalent among athletes and regardless of what is causing the URTI, their recurrence among athletes can cause fatigue that negatively impacts training and performance. As we will discuss further, probiotics – because of their ability to strengthen immunity and regulate inflammation – are a practical nutritional intervention to prevent or lower the chance of getting a URTI. 

In summary, athletes experience inflammation from: 

1) intense training that disrupts the gut barrier function

2) stressors (e.g., poor sleep, poor diet, alcohol, intense training, etc) that negatively alter the healthy balance of gut microbiota

3) non-infectious causes that impact the respiratory system.

Managing inflammation is critical to optimal recovery and in turn performance. Now let's see how probiotics play a role in this management. 

Probiotics Regulate Inflammation

First and foremost, a balanced gut microbiota is highly important because good gut bacteria can strengthen immunity. A decrease in the prevalence of this good microbiota can lead to the growth of bad bacteria that activate immune cells and suppress important regulatory factors (e.g., decreased synthesis of immunoglobulin A (IgA) and lower levels of important anti-inflammatory cytokines such as IL-10 and TGF-ß). This dysbiosis can lead to chronic inflammation. The science suggests that probiotic supplementation may reverse dysbiosis, return the gut to a healthy gut and bring inflammation under control. 

Probiotics regulate inflammation by:

Maintaining the gut barrier. A weak gut barrier occurs when there are gaps between the cells that line the intestinal wall. These gaps are a critical factor in the initiation of chronic inflammation. Certain molecules that shouldn’t cross the gut barrier (e.g., metabolic waste and undigested food) and bad bacteria (which can release the endotoxin lipopolysaccharide (LPS) from their cell wall) can enter the blood because of increased gut wall permeability. This is referred to as “leaky gut” and causes endotoxemia, which is pro-inflammatory. The continual release of LPS in the blood leads to low-grade inflammation. Treatment of low-level endotoxemia focuses on repairing the permeability of the gut barrier (i.e., strengthening it). Certain probiotic strains can enhance the integrity and function of the gut barrier by:

  • Strengthening the physical barrier. Some probiotic strains can reduce the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), which causes a leaky gut.
  • Increasing mucin production. The mucosal immune system functions as a barrier and it protects the mucosal layer of the GI, urogenital and respiratory tracts. Probiotics can impact the development and maintenance of the mucosal layer.
  • Producing antimicrobial peptides. These small peptides are a primary defense on mucosal surfaces, especially for alleviating acute inflammation. Certain probiotics are considered powerful activators for producing and regulating antimicrobial peptides.
  • Alleviating the effects of bad bacteria. Probiotics can outcompete the bad bacteria to help maintain the gut barrier.

Increasing the production of short chain fatty acids (SCFAs). Bacteria produce SCFAs when they digest non-digestible carbohydrate (i.e., certain types of fiber). Of the SCFAs, butyrate is important in regulating inflammation because of its anti-inflammatory effects. Butyrate behaves as a:

  • Signaling molecule by blocking pathways that release pro-inflammatory cytokines
  • Regulator for the production of certain cytokines by affecting their ability to travel to sites of inflammation
  • Main source of energy for gut cells, which helps maintain the gut barrier
  • Attaching to immune system receptors to stimulate pathways that release cytokines associated with inflammation.

Not all probiotic strains have the same effects on different signaling pathways, but some can attach to immune system receptors and help certain pathways involved in maintaining the balance in the mucosal layer between pro-inflammatory and anti-inflammatory responses. This influences inflammation by enhancing the production of suppressive and regulatory cytokines.  

Don’t let chronic inflammation hold you back from training and competing. Optimal recovery begins with preparation through probiotic supplementation that will shut down stressors on the gut, which contribute to chronic inflammation and impede performance. 

by Katie Mark, MS

Katie Mark is currently a Master of Public Health candidate at Tufts University School of Medicine. She is a road cyclist working toward becoming a registered dietitian.


Rachel Joyce: On Going With The Flow and Giving Back

Rach smile pose.jpg

We caught up with #SoundAthlete Rachel Joyce to learn what she’s been up to since announcing a hiatus from her professional racing career.

World champion triathlete and Kona podium regular Rachel Joyce will forgo a spot at the 2016 Ironman World Championship to focus on a different adventure: motherhood. With her baby due in the fall, Rachel is staying active through her pregnancy, but also relishing the freedom and spontaneity rarely found amid the rigors of training at the professional level.

“I’ve really enjoyed not really having a schedule,” says Rachel. “There are certain sessions I’ll try and do every week just because I enjoy seeing friends that I train with, but I also listen to how I feel. Some days I’m more tired so I might just do a solo swim. I know that some women maintain a very strict training regime throughout their pregnancy, but for me this is the perfect time to take that pressure off myself and do other things.”

These other things, for Rachel, are many. Just have a look at the laundry list of activities that make up her new day-to-day:

First, there’s her passionate work as an ambassador for two leading women’s triathlon initiatives, Women For Tri and Tri Equal. Rachel has been directly involved with the development of Women For Tri’s new ambassador program and serves as the organization’s point person in her home of Boulder, Colorado. 

“It’s been really fun,” she says. “I want to see the sport grow amongst women. One of the nice things inherent in the sport is the mix between the age groupers and the pros, and it’s inspiring to see how enthusiastic and generous the women we are engaging with are in giving their time to share the sport with others.” 

Among Tri Equal’s initiatives, the organization is best known for the drive to achieve an equal number of men and women pros in Kona. 

“I think that ties in quite nicely with the Women For Tri objectives, because beyond growing the sport at a grassroots level, it’s important to lead by example on the professional side of things,” says Rachel. “We haven’t succeeded at getting equal numbers, but we’re not going to give up.” 

Also on Rachel’s agenda are coaching duties, a title she is earning through Ironman University. 

“I only have a few clients but it’s been really fun working with them. My goals are very different this year, but I have enjoyed taking others through a training program to reach their goal.”

And her mentoring doesn’t end there. Taking a detour from triathlon, Rachel serves as an English teacher volunteer through Intercambio, an organization that provides cultural integration and English language classes to immigrants in Boulder County. 

“I’m an immigrant, although I happen to speak English,” says Rachel. “It sometimes feels very separated in Boulder, and you could miss that there is a large immigrant population. I’d really like to see a more intercultural, integrated community. And while I don’t want to get too political, I want to do what little I can to counter the negative dialogue that’s been created about immigrants and integration. It’s a small thing that I’m doing through volunteering, but it is important to me.”

To further expand her own cultural horizons, Rachel attends an intensive Spanish course three mornings a week. She’s always wanted to master a foreign language and says, “It seemed like a perfect time to throw myself into it.”

As a soon-to-be mother, Rachel is also more invested than ever in her physical well being. She uses Sound Probiotics to safeguard both her own and her baby’s immune health.

“I started using the product about 18 months ago,” says Rachel. “The more I read about gut health, the more I see that it’s central to how you absorb nutrition,  to the health of your immune system and your mental well being. So Sound Probiotics are a staple in my daily routine. Even if I don’t take another supplement – if I miss my Vitamin C, for example – I take my probiotic every day. And now that I’m expecting, I’ve read articles saying that taking a probiotic – during pregnancy and after you give birth, if you decide to breastfeed – can help with your child’s future health and help prevent acid reflux.  I wasn’t unhealthy before I started taking Sound, but professional sport is about finding your optimal health. Now I want to do everything I can to be as healthy as possible and create a healthy environment for my growing baby.”

With all of Rachel’s interests, community activities and outstanding athletic accolades, she’s an obvious inspiration to many. Yet she’s hard pressed to see herself in that light. 

“I don’t see myself as inspiring people,” says Rachel. “I would love it if I do inspire people but I am not sure that can be a goal in itself. I love what I do and I’m mostly driven by doing stuff that I enjoy and things that feel right. That’s why I got involved with these various projects. Triathlon has had such a positive impact on my life, and that’s why I think it would be great if we could reach more women and get them into the sport. That comes from my personal experience in the sport and how it makes me feel. It makes me a more positive person, more confident, and that’s something I would love everyone to have the opportunity to feel.”

“Plus,” she adds, “When you’re training all the time, life can be quite mono-dimensional. It’s been quite nice to add other things in that key into other important parts of my personality. I would never have had the time to do the things I’m doing now when I was training to race and focusing on Kona. I do want to return to the sport, but I have ambitions for after the sport as well, so this is a good time to explore how I might shape my career after I’m done racing.”

Starting a family is one thing that Rachel and her long-time partner Brett wanted to do, and the experience thus far is providing a fresh and welcome perspective. 

“Not all of pregnancy has been easy,” says Rachel. “I definitely found it hard in the early days just because I didn’t feel great. But it feels really nice that it’s not me that comes first now. I like that aspect – thinking about another person and making this baby my priority. Sometimes I have struggled in the sport because you need to be selfish at points and so singularly focused. That’s necessary to reach your potential, but I also found it difficult at times. So it’s nice to have shifted focus. It’s a relief in a lot of ways.”

As for when we might see Rachel back on a triathlon start line? 

“I think nothing can really prepare you for having a baby except for when you actually have it,” she says. “I don’t have a concrete image of how life will be after the baby comes and I’m not pressuring myself that I have to be back into training at a certain time. I really feel that I’m going to go with the flow and see what happens.”