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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

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.

References

What's in the Water?

It is no surprise that triathletes and swimmers expose themselves to some nasty waters all in the name of training and competition. Contaminated water is an occupational hazard. But what kind of impact does this have on an athlete? Is there really a risk of increased illness? Unfortunately, whether you are a triathlete, swimmer, or surfer your risk for GI illness is increased by inadvertent ingestion of contaminated water.

This past summer the Associated Press tested the water off the beaches of Rio de Janeiro, the site of the 2016 Summer Olympics. What they discovered was that “...the waters where Olympians will compete...are rife with human sewage and present a serious health risk for athletes.” Of course, there isn’t a single Olympian that is going to forgo the biggest event of their athletic career because of dirty water.  

Most triathletes have experienced the possibility of a canceled race due to high levels of water contamination (I’m looking at you, Boulder Reservoir!). It’s naïve to think, however, that when the race isn’t canceled the bacterial load has magically disappeared. It hasn’t. The level of bacteria just dropped below a certain threshold during that moment and at that spot where the water was tested. Ultimately, testing can give us a good range or indication, but it can only be a general guide, and as I stated earlier, despite following EPA testing, swimming in U.S. recreational waters increases your risk for GI illness. 

What does this increased risk for GI illness mean for athletes? We certainly are not going to stop training and competing in open water just to avoid contamination exposure. However, there are steps we can take to avoid getting sick:

  • Check your municipality’s test results: All recreational waters must be tested for contamination, so if you plan on training in open water you can always check your city's most recent testing results
  • Avoid swimming after a recent storm: You may want to avoid swimming in your local lake or reservoir if there has been recent rain. Run-off from a storm can increase bacterial load in the water. 
  • Stop choking down water: How is your swim technique? Full rotation – breathing out through both your nose and mouth – staying relaxed. They are some basic tips, but especially for the novice swimmer poor technique can mean more water down the hatch and that means more of those potential nasty bugs in your system.
  • Get defensive: Although there has not been specific research examining recreational swimmers and the use of probiotics in the prevention of GI illness from contaminated water exposure, some of the same bacteria can cause traveler’s diarrhea (ie, E.coli). Probiotics have been found to prevent traveler’s diarrhea, so it’s possible that they could be helpful in preventing infection from bad water as well.  

Staring at that same black line for 1500m can get awfully boring. Outdoor training in the open water is a great change of pace and a must for any competitive athlete. We’re certainly not talking about contracting the plague from your local lake. But when an infection means missed training days, or your A-race is canceled because of bacteria levels in the water, it becomes a serious matter. And athletes are taking notice – especially those looking to punch a ticket to Brazil. Unfortunately, a new round of testing in December of 2015 revealed that the waters off Rio were worse than they were before. Luckily, they have eight months to literally get their shit together.

Inflammation, Your Gut and Performance

inflammation-blog

We recently had a great conversation with our friends at Endurance Planet about gut health, probiotics, and the endurance athlete (check out the podcast). The question of how inflammation affects performance came up and I felt like revisiting the issue a bit more extensively in this post.

Inflammation is not necessarily the boogeyman that it is often believed to be. To understand how inflammation might affect athletic performance, let’s first define inflammation and its role in the body.

Inflammation is an extremely complex and dynamic process. It functions appropriately in our bodies as a means of warding off infections and responding to injured tissues. Think of inflammation as a cascade of events with the infection (injury, toxin, or stressor) resulting in the release of particular cells and chemicals that go after the infection or injured tissue to either destroy the offending stimulus or protect/repair the injured tissue. Inflammation is what leads to pus and to the straw-colored fluid in blisters. But most often the reaction goes on unseen inside our bodies.  

It is important to understand that infection is not the same as inflammation. An inflammatory response occurs as a result of an infection, but that is not the only time inflammation occurs in the body. Exercise is a well established cause of inflammation too. Exercise can lead to tissue (ie, muscle) injury, which sets off a cascade of inflammation. However, this is a short-term effect. Exercise has actually been found to have a long-term anti-inflammatory effect

So when is inflammation bad? This is a tough question without a good answer, but I think it would be generally accepted that inflammation, when chronic, is doing more harm than good. When does inflammation become chronic? Well, neither that blister nor that cold will last forever, so for the majority of us it’s not nasty bugs or autoimmune conditions that are driving chronic inflammation. It is our diet and stress!

The link between our diets and chronic, systemic inflammation is thought to be mediated through our guts. A less diverse microbiota, associated with a typical Western diet, has been linked to increased intestinal permeability. This process allows substances that should not cross into the bloodstream do so, triggering an inflammatory response. This process has been linked with increased insulin resistance and in turn obesity and type II diabetes. Current research is also pointing toward chronic inflammation as a culprit in the development of cardiovascular disease and even depression.

How does inflammation affect performance

As I mentioned earlier, exercise actually causes inflammation, but it dissipates within hours to days with adequate recovery. The problem arises, when you don’t allow for adequate recovery or add on other stressors (ie, poor diet, poor sleep, alcohol, etc) that augment the inflammation leading to, you guessed it – chronic inflammation. At this point, you are treading in dangerous territory and run the risk of overreaching and overtraining.  IF we are to assume that these syndromes represent a state of chronic inflammation – or are in fact synonymous, then we can most definitely say that they affect performance!

What to do about it

Proper Nutrition: Despite some good guiding principles with nutrition and hydration, what you consume is a very personal choice, and it takes a lot of self-experimentation to figure out what works. But the bottom line is that you should take as much care with what you put in your body as you do with picking out your gear. Check out Endurance Planet for several great podcasts on nutrition for athletes as well as the website for a leading exercise physiologist Asker Jeukendrup

Proper sleep: Get it! Read more about gut health and sleep here

Maintain a healthy gut: Personally, this doesn’t have anything to do with adhering to a specific diet or relying heavily on a particular food group, but rather focusing on the least refined, most natural foods I can find. I also eat a wide array of fermented foods/drinks like miso, kombucha, and sauerkraut. The goal is to increase microbial diversity in our gut. Increased microbial diversity is associated with less inflammation.

Proper sleep and reducing stress also have beneficial effects on gut health.

Avoid unnecessary antibiotics. Don't be quick to accept an antibiotic prescription. Ask your doctor if it is really needed and if "waiting it out" might be a better option (as is the case for a cold and most sinus issues). 

Avoid excessive alcohol

Don't take NSAIDs for pain

Get a coach: A coach can keep track of your training intensity and see patterns in your performance that will prevent you from overreaching and aid in proper recovery. A good coach is worth every penny! 

 

 

 

What athletes should know about leaky gut

leaky-gut-syndrome

You have probably heard the term "leaky gut" before, but what does the science actually say  about this phenomenon and how does it relate to endurance athletes?

When we talk about leaky gut, we are really referring to an increase in intestinal permeability. This does not mean that there are holes in the intestines, but rather that the spaces between the cells that make up the intestinal lining have widened. Normally, intestinal cells are closely packed next to each other to form tight junctions that only let small molecules pass from the intestines into the bloodstream. During times of increased permeability, the tight junctions loosen giving larger molecules and toxins the opportunity to leak into the bloodstream.

Increased intestinal permeability is a particularly important issue for endurance athletes because exercise has been shown to draw blood flow away from the gut which increases permeability and may lower the efficacy of the immune system. This can lead to common side effects that many endurance experience such as cramps, diarrhea, nausea, and an increased risk of infection. One study found that permeability increases with running intensity so the harder you train, the higher your risk for these adverse effects. But don’t worry, no one is telling you to lighten up on your training! There is actually a way to help prevent the exercise-induced increase in permeability: probiotics.

Probiotics have been shown to prevent intestinal permeability and even prevent exercise-induced permeability specifically. The idea is that probiotics form a protective barrier around the intestinal cells which reduces permeability and supports the immune system. This may explain why probiotic supplementation is associated with fewer gastrointestinal and respiratory illnesses in athletes.

Probiotic supplements are a great tool to help you stay healthy while training hard, but be sure to choose your probiotic wisely. If you read our post on why probiotic strains matter, you will remember that a probiotic should contain the types that have been shown to result in the benefits you are looking for you.

by Katelyn Collins

Katelyn Collins, is a future registered dietitian with a passion for probiotics, a knack for nutrition communications, and a love of athletic pursuits on both land and sea.

 

Tips for training and racing in the heat

training-in-the-heat

The hot summer days are upon us so it’s a good idea to be ready for training in the heat since not being prepared can seriously affect your training and performance.

Why is training and racing in the heat potentially harmful for athletes?

For a long time we thought that heat stress and heat stroke were simply the imbalance of heat loss from the body during exercise in the setting of high air temperatures – the body can't cool itself well enough in the hot temperatures and hyperthermia sets in. We now know that the stress of heat in athletes is more complex than that.

In conjunction with the imbalance of heat regulation in the body, heat stress and ensuing heat stroke, also involve an inflammatory cascade. This inflammation is felt to be primarily mediated by the gut. Since so much blood is diverted away from gut and to the muscles during exercise the tissue of the gut becomes “leaky.” This allows toxins to cross into the bloodstream resulting in a process called endotoxemia. Exercise-induced endotoxemia is now felt to be one of the primary causes of hyperthermia in athletes.

The release of toxins into the bloodstream and the subsequent increased core body temperatures not only contributes to gastrointestinal symptoms in athletes but results in impaired performance through decreased strength and mental fatigue. And if that weren’t enough, endotoxemia can weaken an athlete’s immune system leaving you more susceptible to overtraining and illnesses (this is why there is a higher rate of respiratory infections among high intensity athletes)!

So what can you do to prevent heat related stress and impaired performance?

Here are a few suggestions for before, during, and after your training session or race:

Before:

  1. The obvious: sunscreen, light colored clothing, and being fully hydrated

  2. Pre-cooling: drink ice water or turn a pre-training drink into a slushy

  3. Don’t use ibuprofen or aspirin: these drugs can increase the gut’s “leakiness” causing even more problems.

  4. Probiotics: studies have shown that probiotics can reduce the amount of inflammation and endotoxemia that results from stress of exercise and the heat. Probiotics have also been shown to increase run time to fatigue in the heat.

During:

  1. If you're not in a race, take more frequent stops to refill your water bottles. For really hot days you may need to consume at least double your normal water intake!

  2. Don’t forget about salt! Read my tips on salt intake here.

  3. Cold sponges or ice packs: Cyclist and runners could take this tip from triathletes who stuff cold sponges into their jerseys to keep them cool. While I’m riding I like to put small sponges in my arm pits or near the femoral artery since these areas are closer to blood vessels. Otherwise, pouring water over yourself is always an option.

  4. Be aware of pacing: as the heat rises your muscle activation and subsequent power output may diminish – adjusting accordingly will be important so you don’t blow up too soon.

After:

  1. Dunk yourself in an ice bath or if that’s not available drape cold towels over you.

  2. Keep drinking: Just because your workout is finished doesn't mean you should stop hydrating. On those hot days your best bet is to weigh yourself before and after your workout and drink that amount over the next 24 hours (1kg roughly equals 1L of water).

Just like your races, performing well in the heat comes down to being prepared.