Inflammation is a normal part of life. You cut your finger and your immune system mounts a response to protect you from danger. You roll your ankle and the inflammatory cascade is set to bring immune cells to heal. Inflammation is inherently a protective mechanism the body possesses to keep it safe and healthy, but when inflammation becomes excessive and chronic, it can be hugely problematic, for athletes in particular. In this article we will be focusing on inflammation and athletic performance.

The thing is, a lot of athletes don’t even know they’re inflamed. This means that they’re not doing anything to mitigate inflammation, yet still wondering why they’re not seeing improvements in their performance or they’re not recovering like they used to.

Whether that’s you now, or you’ve been there before, we’re talking about all things inflammation, how it can affect your performance, and the best ways to combat inflammation to get your performance and recovery back on track.

What is inflammation?

We’re all probably familiar with the term inflammation, but not many people know what inflammation is despite the swelling, redness, and sometimes pain that frequently accompanies it. By definition, inflammation is one of the most central processes required for defence against injuries or infection ^1; it’s the immune system’s response to an irritant, whether that’s an allergen, a foreign object, or a splinter in your finger.

Regardless of the condition, the mechanism of inflammation is generally the same, a chain of organized and dynamic responses that involve both cellular and vascular events with specific humoral secretions. Sounds complicated, but here is the typical chain of events. When the inflammatory pathway is triggered, white blood cells (monocytes, basophils, eosinophils, and neutrophils), plasma, and fluids accumulate at the site of inflammation. There are also several mediators and other signaling molecules (histamine, prostaglandins, leukotrienes, oxygen- and nitrogen-derived free radicals, serotonin) that are released by immune cells. These further contribute to inflammatory events by dilating blood vessels to allow for greater circulation to the affected area.

In any case, the inflammatory response is triggered in two phases: (1) acute and (2) chronic, each mediated by a different mechanism ^1. The acute inflammatory response can further be classified into vascular and cellular.

ACUTE VS. CHRONIC INFLAMMATION

Before we dive into the effects of inflammation on athletic performance, we need to differentiate between the two kinds of inflammation in the body, acute and chronic.

Acute inflammation is a short-term process that is triggered in response to tissue injury, usually appearing within minutes or hours. It is characterized by the five cardinal signs of inflammation ^2:

1. Redness
2. Heat
3. Pain
4. Swelling
5. Loss of function

In a healthy response, the inflammatory response is activated, clears the pathogen (or whatever triggered the response), initiates the repair process, and abates.

However, inflammation itself is a process that can damage healthy cells when prolonged, which can trigger more inflammation. It’s what some researchers call “runaway inflammation” and it can lead to severe organ failure if not treated. And when you combine systemic inflammation with an accompanied infection, it’s defined as sepsis, a common yet frequently fatal condition.

While acute inflammatory responses are protective, without timely resolution they can lead to the development of chronic inflammation.

Studies suggest that the presence of certain social, psychological, environmental, and biological factors can prevent the resolution of acute inflammation and, in turn, promotes a state of low-grade systemic chronic inflammation that’s characterized by activation of immune components that are distinct from those activated during an acute immune response ^3.

“Chronic inflammation can lead to cardiovascular disease.”

One of the big issues associated with chronic inflammation is that a shift from a short-lived (acute) to a long-lived (chronic) inflammatory response ultimately causes immune tolerance and can lead to major changes in tissues and organs, along with normal cellular physiology, which can increase the risk for various non-communicable diseases. Systemic chronic inflammation impairs normal immune function, leading to increased susceptibility to infections, but also other immune related diseases. And studies actually show that systemic chronic inflammation leads to several diseases that collectively represent the leading causes of disability and mortality worldwide ^3. That includes cardiovascular disease, cancer, diabetes mellitus, chronic kidney disease, NAFLD, and autoimmune and neurodegenerative disorders.

How does inflammation affect athletic performance?

There’s no end to the research supporting the link between chronic systemic inflammation and disease outcomes, but what about athletic performance? Can inflammation really be that detrimental?

The answer: Yes.

But first let me explain what happens during exercise that triggers the inflammatory response. It’s not a straightforward link because exercise increases inflammation, but also reduces it. Whether you’re exercising daily or not, you’re probably familiar with the ‘good’ kind of sore that shows you just kicked a** in the gym. You’re probably also familiar with the ‘bad’ kind of sore that goes along with pulling a muscle or spraining a joint. When you’re struggling to walk up and down the stairs because your quads and glutes went through a killer lift yesterday, it’s generally a sign that your body is in full-out repair mode. However, sharp pains when you walk? That’s not what we want and is likely a sign of unwanted inflammation.

But the reason why we become inflamed after workouts, especially ones involving heavy weight, is because exercises cause tiny micro-tears in muscle tissue that the body essentially sees as damage and the inflammatory cascade is set off.

There are three types of muscle actions that happen during training: Concentric, eccentric, and isometric. The eccentric action is during the lowering phase of the movement when the muscle lengthens because the contraction force is less than the resistive force. And with resistance training, eccentric actions cause a greater extent of muscular damage than concentric actions ^4. The body’s physiological response to tissue injury is inflammation and the subsequent release of cytokines. These cytokines then facilitate the arrival of neutrophils, monocytes, and lymphocytes to the affected muscle tissue for repair.

These responses that ensue are critical for host defense and natural tissue homeostasis, but also initiate the elimination of noxious compounds and damaged tissue that could cause further aggravation ^4. For example, uncleared lactic acid is what contributes to delayed onset muscle soreness (DOMS) the few days following an intense workout. But it also dilates blood vessels to increase blood circulation to the affected area, which brings in immune cells and other compounds needed to repair the damage. That’s how muscles increase in size. Without this inflammatory response, your muscles wouldn’t get what they need to repair.

But here’s the thing with this type of inflammation..

A single bout of resistance training does cause a short-term increase in plasma cytokines (pro-inflammatory compounds), but the long term effects due to adaptation to training result in LOWER plasma pro-inflammatory cytokines both at rest and as a response to exercise! [5] That’s where you see that exercise increases but also decreases inflammatory markers. One of the most obvious and major adaptations that happens with resistance training is increases in muscle mass, which is the result of enlargement of the actual muscle fibers (hypertrophy) themselves, not by an increase in their number. And in order for this to happen, the inflammatory response is necessary.

How inflammation influences exercise

The link between inflammation and exercise is anything but simple and straightforward, but there are a few key things to know.

The acute inflammatory cascade in response to exercise is essential for repairing muscle and allowing for growth and adaptations following bouts of resistance training, or prolonged endurance activities. However, what athletes need to be really mindful of is that acute inflammation doesn’t turn chronic.

Chronic inflammation can start to creep up for athletes when they’re constantly training at high and heavy intensities and not allowing their body to recover sufficiently. As most people know, exercise increases production of free radicals and elevates levels of oxidative stress (all metabolically active tissues produce ROS as a byproduct of normal metabolism). And some oxidative stress is desirable during exercise because the ROS released from damaged muscles regulate cellular repair ^6. However, when oxidative stress becomes pathologic, these ROS can trigger inflammation, muscle fatigue, and soreness that severely impedes on athletic performance ^7.

This is what we call overtraining syndrome and it’s fairly common in a lot of high level athletes. And while it may seem like more is better, your body requires adequate rest and recovery if you want to perform at the top. Overtraining is not the way to do that. Once you hit overtraining status, it can take several months to make a full recovery, so preventing it while you’re ahead of the curve is always ideal.

5 ways to reduce inflammation and support a faster recovery