CNN recently posted a news article called, “Why Intense workouts are leading to a life-threatening condition.”
One of my colleagues in the field of physical therapy, Dymire Jones, posted the article and mentioned how it was an example of fear-mongering. Fear-mongering is the action of deliberately arousing public fear or alarm about a particular issue. For example, Donald Trump said that “the number of police officers killed in the line of duty has risen by almost 50% compared to this point last year.” In reality, the rate of police officers killed as a result of criminal activity is trending downward. This has been the pattern since the 1980s.
The CNN article can understandably cause people to think twice about working out “too hard.” But is it true? Another colleague, Jared Aguilar, asked me to fact check the article since part of my mission is to provide clear facts about fitness.
A summary of the CNN article is that intense workouts like P90x, spinning, CrossFit, weightlifting, and running can lead to a condition known as rhabdomyolysis. Rhabdomyolysis can be a serious. With this condition, muscle is broken down and chemical changes can cause muscle cell content to release into the blood. This quick release of breakdown products into the blood puts stress on the kidneys, which work to clean the blood. There are several different types of rhabdomyolysis, such as compression (ex: pinned under a car), infection, and autoimmune disorder. This article focuses on exertional rhabdomyolysis; this is muscle breakdown due to an excess of high intensity exercise.
Symptoms of rhabdomyolysis are muscle pain, weakness, and dark urine, ranging from pink to dark black. However, the signs and symptoms can vary among patients. Muscle pain and weakness might be localized to one particular muscle group, like the calf muscles. However, over 50% of patients with rhabdomyolysis do not mention muscle pain or weakness. Other symptoms can include: swelling, cramps, low blood pressure, fever, nausea/vomiting, tachycardia (high heart rate), and malaise (generally not feeling well.) In general, rhabdomyolysis has two main complications: kidney failure and compartment syndrome.
Kidney failure sounds terrifying, and it can be! However, there are two different categories of kidney failure: acute and chronic. Chronic kidney failure is often what comes to mind when someone mentions kidney failure: an image of a person looking pale hooked up to a huge machine that cleans their blood. In the case of rhabdomyolysis, an acute kidney injury/failure occurs. These acute kidney injuries, while serious, do usually recover; the injury and decreased function does not last like it does in chronic kidney failure. An acute kidney injury occurs in 33% of patients after the initial presentation of rhabdomyolysis. When rhabdomyolysis is suspected, aggressive hydration occurs to prevent this injury from occurring or from progressing further. In the article, they talk about how one woman was put on dialysis. However, if you keep reading, you see that the woman makes a full recovery in two weeks. This is an acute kidney injury, not chronic.
Next, the article talks how if the man’s legs had kept swelling, they might have to ‘cut them open’ due to compartment syndrome. Compartment syndrome occurs when muscles enclosed in fascia compartments that don’t stretch are damaged; the resulting increase in pressure cannot escape. (Picture fibrous sleeves around a group of muscles.) This increased pressure occurs because the damaged muscle becomes swollen with blood and edematous (swells); it also limits the normal lymphatic drainage to this area. Combined, this limits normal blood flow and can lead to further damage. As the article mentioned, if the pressure gets too high, the fascia sleeve must be opened to allow for pressure release. The fluid treatment started for rhabdomyolysis helps to reduce the swelling in this area; often, the surgery is not needed. The prevalence of compartment due to exertional rhabdomyolysis is not clear; in a review of pediatric cases of compartment syndrome, 15% were due to exertion. More often, compartment syndrome occurs with trauma such as fractures.
So, what does this mean? Should intense exercise be avoided? Is CrossFit going to cause kidney failure? Does your spinning class put you at risk for compartment syndrome? What is my “Snopes” rating?
To give it my best effort of a “Snopes” result, I’d give it a ‘mixture’ rating. The article brought up good points, but it also sensationalized the injury and encouraged a gut reaction of fear and worry. Intense exercise doesn’t have to lead to a ‘life-threatening condition’ like rhabdomyolysis, if exercise training is done properly.
Most often, exertional rhabdomyolysis occurs in ‘first-timers’ starting an intense workout. Walking off the street into a spinning class can be rough, just like Christopher Everett experienced! The research in the article supports the idea that being a ‘beginner’ increases your risk. Out of 46 cases of exertional rhabdomyolysis after a spinning class, 42 cases occurred after the participant’s first class.
However, this does NOT mean that spinning is going to lead to exertional rhabdomyolysis. Instead, this research supports the idea of working up to an intense workout. When I started my first spinning class, I ended up taking breaks about every 5 minutes. I spent a lot of time in the ‘saddle’ and my ‘climbs’ were usually cut short. As an exercise professional, I realized that I wasn’t up to the level of the instructor. Instead of pushing it and feeling ill or quitting, I modified by increasing my recovery time and reducing my intensity. I often modify intense workouts because I’m not ‘there’ yet, but I enjoy the challenge.
One of the keys things that we were taught in exercise physiology is the 10% rule. In general, exercise should be increased in intensity by 2 – 10% at the most per week. For example, if I went 10 miles in my first spin class, I should aim to do 11 miles the following week (10% of 10 = 1; 10+1 = 11). If I squat 90 pounds in my first CrossFit class, I should hope for roughly 100lbs the next week. It’s also important to keep in mind delayed onset muscle soreness or DOMS. If you are sore longer than 2 days post workout, you need to decrease your intensity to allow for proper recovery. (To learn more about DOMS, check out my article, “5 Ways to Explain DOMS to Your Patients.”)
Finally, when you plan to make a big change in your exercise level or intensity, I highly recommend that you consult with an exercise professional to determine if this can be done in a safe way. An exercise physiologist, physical therapist, and even a certified personal trainer can go through a screening process with you to make sure that activity is increased in a healthy manner. These professionals will consider your medical history, family history, and personal factors to work with you to determine the best plan.
When I was first starting to increase my workouts by including ‘sprint’ intervals working at 80-90% of my heart rate max, I thought out those previous factors to make sure that it was a good idea. And if I felt at all ‘sick,’ I would slow down or stop. I have driven my heart rate to 201bpm (beats per minute) without adverse health effects, other than dreading walking up the stairs to my third floor apartment. Working out intensely is safe, but only if it is done in a proper manner.
Finally, I would like to give a shout out to “The Duck Legs Podcast” team Dymire Jones, Jared Aguilar, and Tyler Adams for the post inspiration. The Duck Legs Podcast is a show hosted by these two physiotherapy students seeking to gain wisdom & knowledge from successful professionals. The show’s name is based off a quote by Jacob Braude: “Always behave like a duck: keep calm and unruffled on the surface, but paddle like the devil underneath.” Their podcast explores the tools and traits that can help people just like you to overcome challenges and to truly thrive through discussions with guests like @Greg Todd, PT, OCS, CSCS; Jerry Durham; Dr. Quinn Henoch and more!
What questions do you have? Feel free to post below or shoot me a personal message. I’d love to help out, and if I don’t know the answer, I will do my best to refer you to an expert who can help. I have included my references below if you would like to learn more!
Much of what I have learned about physical therapy and online health/wellness, I have learned from Greg Todd, the founder of Physical Therapy Builder. He is a fantastic physical therapist whose mission is to help physical therapy students and physical therapists provide patient focused care without becoming overwhelmed. Greg Todd is also known as a “social media guru,” and I have a lot of thank him for. I highly suggest his courses, especially Smart Success PT. In May, I attended Smart Success PT Live, a business, marketing, and branding course by some of the top PT entrepreneurs in the field.