running

Should You Race When You’re Sick?

July 23, 2017 By Larry Creswell, MD Leave a Comment

We’ve had a fair amount of discussion here at the blog about long-term health, chronic heart conditions, and how exercise may or not be safe. We haven’t talked much, though, about acute general medical conditions, such as simply being “sick.”

Should you race when you’re sick? And, if you do….what might the consequences be?

I had a recent conversation with Chad Asplund, MD, the medical director for one of the Ironman 70.3 races, and Jon Drezner, MD, team physician for the Seattle Seahawks and an editor for the British Journal of Sports Medicine. We were talking about making a list of the concrete steps that triathletes could take to avoid serious medical problems on race day. Dr. Drezner drew my attention to a scientific report from last year that addressed this issue in long-distance running.

Let’s take a look at the study.

The Study

The team of investigators, from Cape Town, South Africa, is involved in the race-related medical care for a collection of on- and off-road running events ranging from “fun runs” to the 56-km Two Oceans Marathon, involving more than 25,000 runners each year. Over the past several years, this group has focused on studying this athlete population with an eye toward identifying, introducing, and testing interventions that might decrease the risk of race-day medical complications in participating runners. Collectively, their work has become known as the SAFER (Strategies to reduce Adverse medical events for the ExerciseR) studies. I’ve previously written here at the blog about the SAFER I study that looked at the “medical toll” of running races.

In the SAFER IV study, the investigators studied the impact of pre-race acute medical illness and do not start (DNS) and do not finish (DNF) rates for runners who competed one year in the 10-km or 22-km trail runs or the 21.1-km or 56-km Two Oceans events (1).

In the 3-5 days before each race, participants were offered the opportunity to complete an online questionnaire about any acute medical symptoms or illnesses that were present pre-race. The questionnaire included both systemic symptoms (headache, general muscle pains, cough, general joint pains, fever) and non-systemic symptoms (sore throat, runny nose, general tiredness, blocked nose, diarrhea, sore ears, abdominal pain, nausea, wheezing, bladder infection, skin rash, vomiting).

Among the participants, 7,031 runners completed the questionnaire. Any runners who reported symptoms received by email some educational material that suggested they not return to running until all symptoms were gone and they felt well again.

The Findings

A total of 19% of respondents reported at least one symptom during the pre-race period; this included 7.5% who reported systemic symptoms. The remaining 81% reported no symptoms (the control group).

In the control group, the DNS rate was 6.6%. In the symptomatic group, the DNS rate was 11.0%. Interestingly, despite the availability of the educational information for the symptomatic group (that recommended not exercising until runners felt well), 89% of those athletes started the race. For those runners who reported any systemic symptoms, the DNS rate was 15.1%.

In the control group, the DNF rate was 1.3%. In the symptomatic group who started the race, the DNF rate was 2.1% (1.6 times greater than control). For those runners who reported any systemic symptoms and who started the race, the DNF rate was 2.4% (1.9 times greater than control).

The investigators concluded: 1) symptoms of acute illness were relatively common during the pre-race period; 2) despite such symptoms and despite educational materials that discouraged participation, most athletes chose to start the race; and 3) pre-race symptoms of acute illness significantly increased the chances for a DNF.

My Take on The Study

This study is intriguing because it is the only prospective study to address the impact of pre-race acute illness on race-related performance, in any sport. First, a couple notes about the study’s limitations are in order.

First, the response rate for the pre-race survey was rather low (26.6%). The authors indicate that the respondents did not differ substantially from non-respondents in terms of demographic data, but whenever a survey response rate is low, there is a possibility of unwanted bias.

Second, no information is available on the reasons for any athlete’s DNF. Clearly, it would be more informative if pre-race symptoms could be correlated with specific race-day medical problems that might cause the athlete to DNF.

In spite of those limitations, the investigators make some important observations in their running population, but these observations can probably be generalized to other athlete populations:

Nearly 1 in 5 athletes were “sick” in the days leading up to their race. This is a lot of participants.
The vast majority of “sick” athletes probably ignored warnings about participating until they were well (although certainly some may have felt better by race day).
Pre-race “sickness” with systemic symptoms was associated with a nearly doubled risk of DNF. That’s a big effect on performance, even if finer distinctions such as finishing times could not be discerned.

Thinking about the implications, athletes and their physicians should be aware of the potential negative consequences of racing when “sick.” Race organizers should consider distributing educational information about these negative consequences, while recognizing that athletes may not accept unwanted advice not to participate. Many factors (investment in training, scheduled time off from work, costs associated with the race/travel) may be barriers in athletes’ acceptance of such advice. Lastly, additional studies would be helpful if they examined: 1) race-day medical conditions and their relationship with pre-race symptoms; and 2) other measures of performance such as actual versus expected finishing times.

Reference:

Van Tonder A, Schwellnus M, Swanevelder S, Jordaan E, Derman W, Janse van Rensburg DC. A prospective cohort study of 7031 distance runners shows that 1 in 13 report systemic symptoms of acute illness in the 8-12 day period before a race, increasing their risk of not finishing the race 1.9 times for those runners who started the race: SAFER study IV. Br J Sports Med 2016; 50:939-945.

Related Posts:

The Medical Toll at Endurance Events

The Medical Toll at Endurance Events

June 16, 2014 By Larry Creswell, MD 2 Comments

Have you wondered about the “medical toll” at endurance sports events? By that, I mean the sum of all the medical problems that occur to atletes during their participation (and perhaps shortly afterwards as well).

It’s an interesting issue, with many practical implications. If you’re organizing a swim meet, you’d be interested in the likelihood of drowning. If you’re participating in a bicycle race, you’d be interested in the frequency of crash-related traumatic injuries. If you’re the spouse of a long-distance runner, you’d be interested in the likelihood of heart-problems for the participants of a marathon. Should your event have a “medical tent” to handle anticipated injuries or medical problems? Where should the medical tent be located and how should it be staffed? How should your local EMS system or hospital prepare to handle athlete-patients? You get the idea.

Yet surprisingly little has been written in the medical and scientific literature about the medical toll of endurance events. There’s probably a bunch of reasons, including the fact that nobody in particular’s keeping track.

This past week there was an interesting report in the British Medical Journal from a group of investigators in Cape Town, South Africa, and headed by Martin Schwellnus. The report, “Medical complications and deaths in 21 and 56 km road race runners: a 4-year prospective study in 65,865 runners–SAFER study I,” describes the “medical toll” at recent editions of the Two Oceans Marathon races. The report and the findings caught my eye.

The Study

The participants in the study were the 65,865 runners who took part in either the 21 km half marathon or 56 km ultra marathon, the premier events at the Two Oceans Marathon races that are held each year in Cape Town, South Africa. They focused on the 2008 through 2011 editions. The weather conditions for these races was generally favorable, with temperatures ranging from 11.5 to 18.2 degress C and relative humidity ranging from 77% to 93%.

Like many long distance running events, these races had an elaborate set-up for provision of medical care on race day, including on-route medical stations, a dedicated medical facility at the finish, and designated hospitals where athlete-patients would be transferred should they need emergency care. Because the system for medical care was so well proscribed, the investigators were able to compile a list of all “medical complications” that occured in the race participants.

The investigators did not consider the most minor of medical complications, such as seeking medical attention at various first-aid stations for minor injuries or requiring physical therapy attention at the finish line. For simplicity, “medical complication” was defined as an episode that required the attention of a doctor. Exercise-associated muscle cramps alone were not considered a “medical complication” unless there were additional symptoms such as confusion, dizziness, nausea, or vomiting. A serious medical complication was defined as a “medical complication that could result in death unless urgently diagnoses and treated.” And finally, deaths were recorded as well.

The Results

Of the 65,865 participants, 64,420 (97.8%) finished their race(s). The finishing rate was 99% for the 21 km races and 97% for the 56 km races.

Two deaths were documented, each in a 21 km race. The fatality rate, then, was approximately 1 per 20,000 participants in the 21 km races. There were no deaths in the 56 km races.

Overall, there were 545 medical complications among the 65,865 participants, a rate of approximately 0.8% (8.27 per 1000 participants). The rate was approximately 0.5% for participants in the 21 km races and 1.3% for participants in the 56 km races.

Included in the 545 total medical complications were 37 that were designated as serious medical complications. This is a rate of approximately 0.06% (0.56 per 1000 participants). There was no significant difference in the overall rate of serious medical complications based on the distance of the race. The serious life-threatening medical complications included:

Ischemic heart disease (including successful resuscitation from cardiac arrest), in 3 runners
Myocarditis, in 2 runners
Serious cardiac arrhythmias, in 2 runners
Symptomatic hyponatremia (low sodium), in 9 runners
Serious metabolic complications, in 5 runners
Serious heat-related disorders in 7 runners (1 with hypothermia, 6 with hyperthermia)
Pulmonary edema, in 2 runners
Serious fluid, electrolyte, or acid-base abnormalities, in 4 runners
Bronchospasm, in 2 runners
Convulsions, in 1 runner

Further statistical analysis was used to evaluate groups of medical complications, depending upon the body’s organ system that was involved. In this analysis, the frequency of complications involving the cardiovascular, musculoskeletal, metabolic, gastrointestinal, and respiratory systems was greater among the 56 km runners than for the 21 km runners.

The Takehome Messages

The chances of a medical complication or serious medical complication were small, for both of the race distances. Athletes should know, then, that these risks are small as they consider participation in an event.

Information like this should inform safety planning on the part of event directors, event medical directors, and events’ local medical communities.

I suspect that the results are generalizable to races outside of South Africa and also to the real-world question of half marathon vs. marathon races which would be typical distances in the United States.

It is a somewhat surprising finding that the only 2 deaths occurred in the shorter, 21 km races. We know from recent detailed studies involving millions of runners that the risk of sudden cardiac arrest at long-distance running events is almost 3 times higher for marathon runners than for half marathon runners. In this study, it’s a statistical oddity–that not enough years were considered to evaluate such a rare end point.

Intuitively, it is not surprising that there would be more medical complications in the longer events. If nothing else, there is more “time exposure”–more athlete-hours spent in strenuous exercise.

I am surprised, though, that the frequency of serious, life-threatening, medical complications was similar for the 2 race distances, I would have guessed that these, too, would be more common in the longer distance races. Perhaps the take home message is the converse–that a shorter race is not necessarily safer when it comes to life-threatening medical complications. And the real world consequence would be that half marathoners not give short shrift to their health before participating.

Lastly, I’ll continue to hope that national governing bodies and large event organizers (eg, World Triathlon Corporation [WTC[) might collect and disseminate information about the “medical toll” at their races. As a sporting community, we would all benefit.

In the News: Marathoners and Coronary Plaque

April 3, 2014 By Larry Creswell, MD 16 Comments

Every so often, a scientific report about runners and heart disease really captures the attention of the media. About a week ago, a report in the March/April edition of Missouri Medicine entitled “Increased Coronary Artery Plaque Volume Among Male Marathon Runners” generated quite a bit of interest and discussion. I’ve written previously here at the blog about the general issue of the “heart healthiness” of long-distance running in a post entitled “Don’t Stop Running Yet!” I still feel that way. But let’s take a look, though, at this new article about marathoners and coronary plaque.

The report is written by a large group of very credible investigators from the Minneapolis Heart Institute, Integra Group, University of Colorado, Medtronic Inc., University of Minnesota, and the Mid America Heart Institute. Included in the group of authors is Kevin Harris, MD, who authored an important 2010 report on triathlon-related fatalities, William Roberts, the Runners World “Sports Doc” and medical director of the Twin Cities Marathon, and James O’Keefe, MD, a one-time triathlete who has been an outspoken critic in recent years of excess exercise.

The investigators report on a group of 50 male participants in the Twin Cities Marathon who had run at least 1 marathon per year for 25 years in a row. The average age was 59 years. None of these subjects had any history of heart disease or any current symptoms suggestive of heart disease. The runners underwent testing that included measurement of the height and weight, blood pressure, and resting heart rate; a 12-lead EKG; and blood tests for serum lipids and creatinine. The subjects also completed a questionnaire about historical lifestyle and risk factors. Each of the athletes underwent a high-resolution coronary computed tomographic angiography (CCTA) study. A control group of 23 sedentary men were identified from a contemporaneous group who were undergoing a CCTA study for some clinically-necessary reason and also underwent the other tests just like the runners did. The subjects and controls were similar in terms of: age, resting blood pressure, height, smoking history, serum creatinine, total cholesterol, and low density lipoprotein (LDL) levels.

Coronary artery plaque “lesions” were identified in both the runners and the controls: 95 lesions in 30 of the 50 runners, and 46 lesions in 12 of the 23 controls. The total volume of plaque was greater among the runners and this was also true for the amount of calcified or non-calcified plaque, as well. There was no difference in the lesion area, lesion diameter, or lesion length between the runners and controls.

Why is this all important? Because coronary plaque is generally associated with problems like heart attack. In clinical practice, we ordinarily discover coronary plaque when we search for a cause of a patient’s heart attack. Or, in recent years, we discover the plaque when an individual undergoes a screening test like a coronary calcium scoring CT scan. And we know from studies of individuals (not necessarily runners) who’ve undergone coronary calcium scoring CT scans that those with high calcium scores, indicating plaques, there is a greater risk of future heart attack. So it’s somewhat surprising that seemingly healthy long-time runners would have more coronary plaque than the sedentary controls.

On the bright side, despite being nearly 5 years older on average than the controls, the runners had significantly lower resting heart rate, weight, and body-mass index (BMI), less hypertension (high blood pressure), less diabetes, and an increased level of high density lipoprotein (HDL), the “good” cholesterol.

All of this news isn’t really new, though. These investigators first reported their findings at the 2011 meeting of the American Heart Association. It’s just now making its way into print, and into a rather unlikely and somewhat obscure medical journal for some reason. Missouri Medicine, the journal of the Missouri State Medical Association, even sent out a press release with advance copies of the article and accompanying editorials to a wide distribution list, all to take advantage of the lead-up to this year’s Boston Marathon. All pretty sensational, really. I can’t recall anything quite like this for research that was already more than 2 years old.

Given their findings, the authors conclude that “chronic excessive high intensity exercise” is the cause for the plaque build-up in the runners. They hypothesize that the mechanism is related to metabolic or mechanical stresses placed on the heart and coronary arteries during running that may be mediated by inflammation. The authors suggest, then, that “some runners” ought to “choose shorter, less exhausting challenges” in order to avoid this problem. On the face of it, this is a neat narrative, but….

1. Although the plaque volume (the total amount of plaque) was greater in the runners than the controls, the percentage of affected individuals in the running and control groups was not significantly different. Remember that 30 out of 50 (60%) runners had plaque identified and so did 12 out of 23 (52.2%) controls. In the statistical sense, those percentages are not significantly different. In terms of the most obvious, and perhaps most important, endpoint–the number of affected individuals with coronary plaque, the prevalence of coronary plaque–the study is essentially a negative study. Negative studies are hard to get published and I suspect this is why this report was published 2+ years after the study was completed.

2. If running was the cause of the plaque build-up, then why did only 60% of the long-time runners have this problem? And why did 52.2% of the controls have this problem, assuming that they were truly sedentary? Obviously the “cause” of plaque build-up in the coronary arteries is multifactorial. The authors can’t have it both ways: running cannot be responsible in the runners yet not responsible in the controls. For the runners, the real question is: what unmeasured variables might account for the finding of coronary plaque. We simply don’t know.

3. What is the consequence of having asymptomatic coronary plaque in a long-time runner? We don’t know. The current study doesn’t address this issue and to my knowledge, no study has. I’ve certainly heard from long-time endurance athletes who’ve been found to have coronary plaque, or elevated score on a coronary calcium scoring CT scan, who ask about the significance of the finding. We obviously need studies to find out what happens to such athletes.

4. What about….other endurance sports? And women? And younger athletes? There are just many, many questions left to be answered.

So, what’s the runner to do? I would still suggest that you not stop running. There’s every reason to believe that exercise is a healthy pursuit and there’s every reason to believe that exercise leads to better longevity, even for long-time endurance athletes. But stay informed. The general issue about the possibility of too much exercise is receiving a lot of attention. More studies are sure to come. And little by little, we’ll piece together the information that will help us determine if there is some sort of “sweet spot” in terms of the amount of exercise that is most heart-healthy.

Two articles on this topic caught my eye this week. Both are good reading. Amby Burfoot, the long-time editor at Running World and winner of the 1968 Boston Marathon, wrote an online piece for his magazine entitled “Heart Risk? Marathoners Have Increased Artery Plaque.” Interestingly, Amby learned last spring that he falls into the category of long-time runners with an (asymptomatic) high coronary calcium score. The second article was by Kevin Helliker in the Wall Street Journal, entitled “Why Runners Can’t Eat Whatever They Want.”

Related Posts:

1. Don’t Stop Running Yet!

2. More on Long-term Cardiac Risk and Endurance Sport

Marathon Safety

August 15, 2012 By Larry Creswell, MD 1 Comment

With the unfortunate deaths over this past weekend at two triathlons, I’ve had several conversations with athletes about the general issue of sports-related sudden cardiac death (SCD).

I’ve written previously about the rate of SCA at long-distance running events. We learned from a careful study (of nearly 11 million runners) reported earlier this year [1] that the rate of SCA is approximately 1 per 100,000 marathon participants and approximately 1 per 300,000 half marathon participants. The mean age of victims was 42 years and 86% were men. For the non-surviving victims in whom autopsy information was available, the vast majority had an underlying heart condition such as hypertrophic cardiomyopathy (HCM), other abnormal hypertrophy, heart valve disease, or coronary artery disease.

Interestingly, the occurrences of SCA were not distributed uniformly along the length of the race. In marathons, the SCA events were much more common in the 20 mile-to-finish segment. Similarly, in half marathons, the SCA events were much more common in the 10 mile-to-fiinish segment. One reasonable hypothesis is that the SCA events in the final miles of the races may be linked to an increase in adrenaline levels as runners lift the pace or surge toward the finish line.

Today, I thought I’d share some recommendations from the International Marathon Medical Director’s Association (IMMDA) that were approved in March, 2010 and address the issue of how athlete’s can best prepare and execute a long-distance running race with an eye toward preventing SCA. You can review the original report to review the rationale, but I’ll summarize the important recommendations here:

1. Participants should be well-trained and have a race plan that matches their level of training and fitness.

2. Have a yearly physical examination being sure to discuss your exercise plans, goals, and intensity at that visit.

3. Consume a baby aspirin (81 mg) on the morning of the race if there is no contraindication to do so. I’d recommend discussing this with your doctor beforehand.

4. Consume less than 200 mg of caffeine before/during a 10K or longer race.

5. Only drink sports drink (or equivalent) in races of 10K+.

6. Drink for thirst.

7. Do not consume NSAIDS (eg, Motrin, ibuprofen) during a race of 10K+.

8. Consume salt (if no medical contraindication) during a 10K+ race.

9. During the last mile, maintain your pace or slow down; do not sprint the last part of the race unless you have practices this in your training.

These are very thoughtful recommendations. The chances of any single athlete suffering race-related sudden cardiac death is small, but athletes should do the reasonable things to help prevent this type of tragedy.

[1] Kim JH, et al. Cardiac arrest during long-distance running races. NEJM 2012;366:130-140.

Micah True, Ultra-runner, 1954-2012

May 24, 2012 By Larry Creswell, MD 6 Comments

We learned recently of the death of Micah True, an ultra-runner, at the age of 58. Bringing back memories of the equally untimely death of runner-athor, Jim Fixx, True also died while he was out for a long run….and also died from seemingly unrecognized heart disease.

In adult life he took the name Micah (from the Old Testament prophet) True (the name of a mongrel pet), but he was born Michael Hickman and in his early adulthood enjoyed a career as a prize-fighter. True turned his attention to ultra-distance running in adulthood and found considerable success. Some have described his lifestyle as nomadic, splitting his time between Boulder, Colorado, and Mexico and Central America. He became interested in and involved with the Tarahumara people (aka Raramuri) of Mexico’s Copper Canyon region and learned from their natural approach to running. True was a central character in the 2009 bestselling book by Christopher McDougal, Born to Run: A Hidden Tribe, Superathletes, and the Greatest RAce the World Has Never Seen. In 2003 True founded the Copper Canyon Ultra Marathon to benefit the Tarahumara and served as the event’s race director as recently as this spring.

On March 27, 2012, True went for a planned 12-mile run in the Gila National Forest, familiar southwest New Mexican territory for the runner. He never finished the run. Several days later his body was found alongside a stream, with some abrasions on his arms and legs. Some speculated that he had gone to the stream to wash up after stumbling along the trail.

Chemical tests during an autopsy suggest that True was mildly dehydrated and had caffeine in his system. The most striking autopsy finding was dilated cardiomyopathy….enlargement of the left ventricle (the pumping chamber of the heart) along with thickening (hypertrophy) of its walls. No specific cause for the cardiomopathy was evident and the coroner speculated that the immediate cause of death was a fatal arrhythmia. Quoting from the autopsy report:

[t]he decedent did not have a regular physician and no medical records particularly electrocardiograms or blood pressure readings were available for review

and

[t]he best determination is that of unclassified cardiomyopathy which resulted in a cardiac dysrhythmia during exertion.

Cardiomyopathy refers to a situation where the heart muscle is weakened. There are a variety of causes. The condition can be inherited. The typical example is hypertrophic cardiomyopathy (HCM), a condition that predisposes an individual to sudden cardiac death (SCD) because of fatal arrhythmias. There are also acquired forms, due in adulthood primarily to coronary artery disease (CAD) or valvular heart disease. But none of these appeared to be the case for True. And occasionally a cause cannot be identified and we call the situation idiopathic (meaning, simply, without identifiable cause). In the absence of any other identifiable cause of death, the coroner is probably correct, though, in attributing True’s death to a sudden, fatal arrhythmia.

If there is a lesson here for athletes, it’s this: even in seemingly healthy, fit athletes, there is the very real possibility of unsuspected–and potentially serious–unrecognized heart disease. Take nothing for granted. Most athletes would be well-served by medical screening for heart problems and by taking any warning signs seriously.