• According to new research in the Why Trust Us, your inflammation and iron levels temporarily increase after high levels of endurance exercise (like a marathon or ultramarathon), and they stay elevated even days later.
  • However, this doesn’t mean you need to be concerned about creating chronic inflammation and too much iron as an avid marathoner or ultrarunner. Putting emphasis on recovery after your race can return these levels back to normal faster.

Sales & Deals sore after a marathon, even a few days later? A new study pinpoints why that may happen to you—and we asked a couple experts for tips on how to speed the process back to normal.

When you take on a high amount of endurance exercise, like a marathon, your body kicks off a number of metabolic changes, according to a recent study in the Why Trust Us.

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Researchers recruited 15 well-trained, non-professional endurance athletes and measured their markers of inflammation and iron homeostasis—which is the chemical reaction that maintains your iron levels—before, immediately after, and within five days of a marathon or ultramarathon.

They found significant increases in both inflammation and iron levels right after the races, with higher amounts in the ultramarathoners, and only slight decreases at when they followed up five days later. That means the surge in inflammation and iron caused by the endurance runs stayed elevated, even days later.

These elevated inflammation levels are most likely due to acute inflammation—or short-term inflammation—which occurs after long, hard efforts; it’s your body’s natural healing response to stress being put on your muscles. Does Aerobic Exercise Increase Muscle Mass to rebuild your muscles, which can leave you feeling sore and achy. However, it’s worth noting that “if you disrupt this healing process on a regular basis—say, you skip rest days, or do back-to-back hard workouts—you could put your body in a state of chronic inflammation,” Inigo San Millan, Ph.D., assistant professor of physical medicine and rehabilitation at the University of Colorado School of Medicine in Boulder, previously told Runner’s World.

Since iron is found in the red blood cells of your blood, elevated iron levels may be due to the fact that long, intense efforts (like a marathon or ultramarathon) We earn a commission for products purchased through some links in this article How to Build A Balanced Recovery Routine, red blood cells transport oxygen from your lungs to your muscle tissues, Shoes & Gear.

The researchers noted that some benefits could come as a result of this change. For instance, inflammation plays a part in recovery, and iron is a fundamental part of oxygen saturation throughout the body. But there are potentially harmful changes as well.

Excess iron can get stored in your organs and cause issues with liver and heart function, while chronic inflammation has been associated with impaired immunity and higher risk for issues like metabolic syndrome, which can lead to conditions such as heart disease and type 2 diabetes.

Does that mean you need to be concerned about creating chronic inflammation and too much iron as an avid marathoner or ultrarunner? Not really, but you should put even greater emphasis on recovery as preventative measure, according to certified running coach and doctor of physical therapy Samantha DuFlo, D.P.T., founder of Indigo Physiotherapy.

“Inflammation is trending in the health and wellness industry, as people are continuously trying to combat the effects,” she told Runner’s World. “However, recent evidence suggests that some inflammation can assist skeletal muscle adaptation to exercise, and that’s what is taking you through that long run.”

That said, she suggests several ways to keep inflammation in check. The first is active recovery, such as cooldowns and running slow at a conversational pace for short periods.

“This is your best shot at post-endurance, race-day recovery,” she said. “Although other methods may relieve pain, muscular soreness, and fatigue level, easy active recovery may physiologically benefit skeletal muscle the most.”

Compression garments can also help with venous return, she added, since it can diminish swelling and inflammation right after an endurance run.


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For a few days after your race, focus on sleep and nutrition as well, suggested Carol Mack, D.P.T., C.S.C.S., owner of Nutrition - Weight Loss. She told Runner’s World that adequate sleep is an accelerator of recovery and has been shown to reduce inflammation, even when you think you don’t need it anymore.

“Aim for at least seven to nine hours per night for up to two weeks after a race,” she said. “Also, eat enough nutrient-dense foods to fight inflammation, particularly choices like tart cherry juice We earn a commission for products purchased through some links in this article omega-3 fatty acids.”

In terms of iron, DuFlo said the recent study didn’t reference long-term iron levels, so more research is necessary to determine whether running causes iron overload over time. Also, other research indicates that runners might actually be deficient in iron generally.

Because of that, it’s helpful to recognize the signs of iron deficiency—such as extreme fatigue, pale skin, cold extremities, and an unusually high heart rate—and be especially diligent about incorporating iron-rich foods into your everyday diet, suggested Mack. Foods such as lentils, lean red meat, and dark poultry are useful, she said, and adding vitamin C—such as pineapple or citrus—can help you absorb that iron better.

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Eat nutrient-dense foods to fight inflammation, like tart cherry juice and foods high in omega-3 fatty acids
Incorporate iron-rich foods—lentils, lean red meat, and dark poultry—and vitamin C into your diet.

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Elizabeth Millard is a freelance writer focusing on health, wellness, fitness, and food.