Whether you’re new to running or have been doing so for some time, are you aware of a condition known as rhabdomyolysis? At its basic level it occurs when exertion results in injury to the muscle fibers causing them to release their contents into the bloodstream; they then travel throughout the body exerting a range of negative effects on our tissues and organs. Although it’s a rare medical condition that can be experienced by those who run or participate in a wide range of sports, it’s essential to be mindful of how it is caused and the signs to be vigilant for so that treatment can be sought if needed, as if allowed to progress it can be fatal.
Runners at increased risk
Although rhabdomyolysis can strike anyone, there are certain factors that increase your risk. Research shows that a sudden increase in activity to that which you would normally participate in is one factor that makes you more vulnerable to the condition. For this reason, beginners and experienced runners alike shouldn’t try to run further or more vigorously than usual without gradually building this up from their current level. It also appears that those with reduced fitness – either as a result of being a novice runner or who have had to take some time out from running due to illness or an injury – are also at increased risk of rhabdo. However, some individuals are genetically predisposed to develop this and for anyone, running in warmer weather without adequate hydration also makes you more susceptible.
Symptoms to look for
Anyone who takes part in running knows that it isn’t unusual to develop sore muscles, which can last for a day or so. However, muscle pain that occurs as a result of rhabdomyolysis is more intense than the typical pain experienced after running. Other characteristics of rhabdo-induced muscle pain is that it persists, is usually seen in conjunction with muscle weakness and also affects your functional ability, so walking and even standing may be difficult. When rhabdo occurs, you will typically feel unwell and symptoms such as nausea, sickness, a high temperature and reduced urine output that appears darker in color, develop; this may also be accompanied by feeling disorientated.
Impact of rhabdomyolysis
The seriousness of rhabdomyolysis is not related to the breakdown of muscle fibers themselves, but the release of their content; notably enzymes, myoglobin and potassium.
- When muscle enzymes are secreted, these cause damage and inflammation to other body tissues and around 25% of people with rhabdomyolysis sustain liver damage as a result. As the liver is important for so many functions in the body, this can interfere with its ability to detoxify chemicals in the blood, produce new proteins and facilitate digestion.
- Meanwhile, myoglobin, which is the equivalent to hemoglobin found in the blood that carries oxygen to facilitate respiration within cells for energy release, travels to the kidneys. Although this allows myoglobin to be removed from the body, this causes kidney damage and within a day or so of muscle damage, kidney failure will typically result.
- Potassium, which is vital to maintain normal nerve and muscle function, as well as fluid balance within the body, is dangerous at high levels as seen in rhabdo and can lead to irregularities in heartbeat and may even cause the heart to cease beating.
- In the most severe 5% of cases, due to these consequences, rhabdomyolysis leads to death.
- To help diagnosis, tests to review levels of blood potassium, blood and urine myoglobin and creatinine kinase (an enzymes present in muscle) are performed; blood tests are also conducted to check kidney and liver function, as well as an electrocardiograph to check the electrical activity of the heart. These tests can help to assess the extent of the damage to the various organs.
Treatment if rhabdo is diagnosed
Although a diagnosis of rhabdomyolysis can be extremely serious, if detected and treated early, someone’s prognosis is greatly improved. If rhabdo is suspected, admission to hospital is necessary to enable the necessary monitoring and treatment. While in hospital IV fluids are administered to expel myoglobin and lessen the chance of kidney damage, though if kidney failure is present, dialysis will be necessary to filter the blood till kidney function improves sufficiently. Insulin is also required, as it helps to lower the raised levels of potassium in the blood by stimulating its uptake by the cells in the body. In the most severe cases kidney problems may persist, but in many cases a full recovery will be made in only a matter of weeks.
Besides making sure that you do not increase your training abruptly, there are a couple of other steps you can take to reduce your risk of succumbing to rhabdomyolysis.
- Firstly, it is important to drink plenty before, during and after running – this is particularly important in hot weather – to aid the removal of any myoglobin in your blood. There is evidence that sports drinks that contain protein may help to reduce the risk of rhabdomyolysis when taken after exercise. However, while it is important to drink sufficient to meet your thirst, remember that hyponatremia can also be an issue if you over-hydrate, so don’t overdo the fluids; equally when training hard or for more than an hour, take a drink with added electrolytes to prevent this problem.
- Additionally, if you start to feel unwell while you are running, you should stop, as this may be a sign that you are over-exerting yourself.
- Now that you aware of the signs of rhabdo, you will appreciate that if you experience intense muscle pain and this is in conjunction with dark colored urine, it is important to seek medical attention to allow this to be looked into.
Being familiar with rhabdomyolysis, its prevention and signs to spot it, is the key to avoiding becoming a victim; spread the word to your fellow runners to raise awareness and potentially save lives.