4 Steps to Save Future Endurance Race Seasons After Epstein Barr Virus (EBV)
If you’re into endurance sports, you know that feeling in the last week or two before the big race of deep exhaustion, mentally and physically. It’s often blamed on the amount and intensity of training, as workouts crest to a crazy peak. You look forward to ‘taper week’, thinking you’ll feel better then.
But what if that feeling is a sign of something else?

Many conditions, from mild to serious, mimic these exhaustive feelings, including Epstein Barr Virus (EBV).
You mean “Mono”? Isn’t that the “kissing disease”?
Yes, that one. (Although it can also be contracted through sneezing or sharing food or drink with an infected person). Most adults have been exposed to EBV sometime while growing up. Those that haven’t can contract it at any time. EBV can also be re-activated later in life, under certain circumstances.
And while some exercise can improve an immune system, there are some theories that heavy exercise (like the kind undertaken training for endurance sports- marathons, long-course triathlons, ultramarathons, etc.) causes immune suppression, possibly putting athletes are risk for EBV and other infections. Studies on these risks have been conflicting.

What are the symptoms?
The symptoms are Subtle—some people have the infection and never know. There may be mild symptoms similar to a simple viral cold. However, in other cases, symptoms can become severely debilitating. Since some of the symptoms of EBV mimic the exhaustion from heavy training levels, signs of an active EBV infection can be easy to miss, including:
- Fatigue
- Decreased endurance
- Difficulty sleeping
Symptoms that can get misinterpreted as a “head cold,” including:
- Sore throat
- Fever
- Swollen Lymph nodes
Less obvious symptoms:
- Swollen Liver
- Enlarged spleen
- Possibly a rash (especially if an antibiotic was recently started for a suspected Strep Throat).
When to question your symptoms?
None of us can run around worried about a case of the sniffles. We certainly can’t stop training for a big race because of them. But if your symptoms drag on or change in quality, if you have an unexplained drop in endurance, or you just don’t seem to “bounce back”, rethink your training (and resting) plan and consider getting a doctor’s opinion.
Obviously, these symptoms could point to a LOT of other diagnoses other than EBV (like anemia, hypothyroidism, etc.). Or they could point to nothing more than overtraining or training too soon after an illness. The only way to know for certain is to see a doctor and get some labs drawn.
- Find the right doctor-:
- When a doctor doesn’t understand endurance training, it’s hard to get them to seriously listen to complaints like not normally being so tired after a week consisting of a 60-80-mile bike rides, coupled with 2-mile swims, and a 15-mile run. What you’re likely to hear is” you just need rest.” (Speaking from some experience here).
- However, sports medicine doctors, particularly those with personal backgrounds in distance training or that have worked with endurance athletes are more likely to realize these symptoms are not typical or normal. They are more likely to at least pursue some labs.
- Get the right labs:
- Ask for EBV specific labs, along with everything else the doctor will want to look for, such as markers for anemia, or other disorders. The doctor can order labs that help discern active EBV versus an older case and labs that indicate if your body is trying to actively fight off a new or recent infection of any kind. Together, as a big picture, these can help guide your diagnosis and recovery plan.
The Toughest Medicine of All
If the labs show you recently had or actively have EBV, you have some soul searching to do. EBV requires rest for recovery. There are no short cuts. There are no antiviral drugs that can, in general, treat EBV. You may need to drop out of the race.
Think hard before you consider toughing it out! Ask yourself:
- How important is that race to you?
- How important is being able to get back to racing this year?
- Do you ever want to get back to racing?
So, What’s the Risk if I ignore it?
If you are even able to train through the exhaustion, it’s important to know that EBV can cause more serious risks, such as spleen rupture, which can cause a life-threatening bleed and requires emergency surgery. Often, this is caused by trauma (as in contacts sports or a fall from your bike), but can also occur spontaneously.
Training through the exhaustion and other symptoms doesn’t allow the body adequate energy to fight the infection, leading to prolonged recovery. Those of us who unknowingly trained through EBV, can attest to the prolonged recovery. Furthermore, there is some information suggesting EBV can lead to Chronic Fatigue Syndrome, although this is not well supported. Check out Jasmine Moezzi for a competitive triathlete’s story and her fight to continue to train and race, despite chronic fatigue from EBV. (No, really check it out. You’ll be cheering for her and smiling for yourself in the end).
Ok, What Do I Need to Do to Get Back to Training?
Some of this you’re going to hate. So just brace yourself and read on with an open mind. Keep your eye on the long-term goal here: returning to what you love. There is a debate about when it’s safe to get back to training. A good plan takes into consideration your baseline health status and the current status of your EBV (active or recent). So, this requires a detailed discussion between you, your doctor, and your trainer/coach to develop your individual plan.
Your plan will likely be based on generally 4 generally accepted guidelines for safe return to sports following EBV, including:
1) Rest
Rest has historically been thought of as weakness in the endurance world. Thankfully, a new drive to include rest as the recovery phase in each workout has made athletes more aware of this much needed tool process. It’s hard, though, to sit and watch a well-planned training program fall apart as a race date barrels closer. Because of this mindset, it’s extremely important to ask your doctor to explain the amount and kind of rest needed. This rest does not usually include even mid-size gentle rides or “recovery runs.”
You should get a clear plan of what to and what not to do. This is an especially important time to have a physician that really understands endurance training.
Yes! But how LONG do I rest?
2) Wait until the spleen is normal again
You’re looking at about 2-3 weeks of rest, at least, while waiting for the spleen to shrink back to normal. You should also have no fever or fatigue before starting training. The enlarged spleen is, by itself, not usually a problem. Until it is. It can rupture. If it ruptures,
emergency surgery is needed. This is serious- a ruptured spleen can lead to internal hemorrhage and death. Contact sports or other impact can cause a swollen spleen to rupture. So, if you’re on a solo bike ride, out in the middle of nowhere, when you take a fall and your spleen ruptures? You could die, if you can’t get help fast enough.
A swollen spleen can also rupture spontaneously. Your doctor can tell you when your spleen is back to normal.
3) Slowly trial mild exercise
Once you are cleared to do gentle exercise, stick to the plan. Don’t overdo workouts, because you feel really good that day. Remember the long-term goal here.
4) Slowly increase exercise to tolerance*
Starting at about 4 weeks, a slow increase to training can begin, assuming your symptoms are gone. (Note- nowhere in the plan does it say to “workout enough to catch up to your original race training plan.”)
Why ME???
It won’t make it all better, but know that you’re in good company, if you contract EBV. Many athletes have dealt with changes to their competition season due to EPV—even some well-known athletes. Check out the following links:
- Chris McCormack– Ironman World Champion
- Mark Cavendish– Tour de France multiple-stage winner and winner of Milano-Torino 2022
- Roger Black- Olympic Medalist track runner
- Jasmine Moezzi- Chronic EBV Fighter and member of IRaceLikeAGirl triathlon team
- Rudy Von Berg– Ironman 70.3 Triathlete Champion now tackling the full IM distance in 2022
Putting it all together:
Yes, there’s a reason I am sharing this information with you. As with many passions, mine is borne from personal experience. EBV ended my 2021 Ironman season on an unexpected note. It’s keeping me out of the 2022 season, currently. For a quick picture of how it unfolded for me, and what it could look like if you try to train through symptoms, keep reading. Or skip to the bottom for links to more information on EBV.
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What undiagnosed EBV could look like during training/racing:
A few short months before Ironman, when my head cold turned into bronchitis, I rested, following the age-old athlete adage:
Symptoms above the chest? Keep training.
In the chest? Rest.
Once the bronchitis cleared enough, I headed out to catch up on my training. After all, the race was desperately close and I had lost precious time. I started out on those 60 and 80-mile bike rides, thinking I was feeling pretty good. Unfortunately, I bonked at about 50-60 miles each ride. I was also having difficulty maintaining nutrition- managing to keep down a measly 400 or so calories with each ride. I wasn’t nauseous, I just couldn’t convince myself to eat. I had similar setbacks with my swims and runs.
Chalking it all up to overtraining, I backed off a little bit, but with the race a couple of weeks away, I couldn’t afford to stop training entirely.
When I stepped to the starting line of Ironman, I had no idea EBV had been sabotaging my training. I kept convincing myself I was exhausted from all the training. It’s really a wonder I made it to the starting line at the race at all. (Actually, it was stubbornness).
It’s also surprising I made it as far as I did on race day, before giving in to my body and dropping out of the race. But by mile 13 of the run, I had only taken in about 400 or so calories the entire bike ride and much less on the run. If your counting, by then I was about 3000 calories under reasonable nutrition support for the day. I had been walking for several miles, barely able to pick up my feet. Still, I thought this was just a day of exhaustion to overcome and get to that proverbial finish line. Of course, in the end, I couldn’t.
Weeks later, I was still unable to recover from the race. My muscles remained completely empty, stinging everyday as if I had just done the race a few days prior. My head hurt. My appetite was gone. I couldn’t sleep well.
That was when I realized something was wrong, got to a doctor familiar with Ironman, got labs, and discovered I had been training and racing with EBV, and what that can mean to long-term recovery.
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For more information on EBV see these sources:
- Return to Play After Infectious Mononucleosis
- Mononucleosis from Sports Medicine Today
- Clinical investigation of athletes with persistent fatigue and/ or recurrent infections