In February this year, two women attending a spin class in Singapore found themselves in the spotlight — but for the wrong reason. They were hospitalised after overexerting themselves during an intense spin session. Spinning is an increasingly popular form of exercise where participants cycle indoors on a stationary bicycle, often to the beat of energetic dance music.
Known medically as rhabdomyolysis (or “rhabdo” for short), overexertion occurs when muscles are so severely overworked or injured that they start to break down. The dying muscle tissues release by-product components such as myoglobin into the bloodstream, which—in large enough quantities— may overwhelm the kidneys’ ability to flush them out via urination. If left untreated, this can lead to acute renal failure and even death. In an April 2021 CNA report, a consultant at Tan Tock Seng Hospital (TTSH) said he saw about five overexertion cases in the past month alone.
The TTSH consultant interviewed in the April CNA report said that of the last 20 rhabdo patients he saw, 19 overexerted themselves during spinning. “Only one case was a young man who went for a 10km run without prior preparation,” he revealed.
According to a research in the New England Journal of Medicine, age matters too. Older people are at higher risk of overexertion, as are men compared to women, and those with a higher level of body fat. Healthcare experts also found that certain individuals are more susceptible to overexertion after intense exercise due to their genetic backgrounds.
If you fall under any one of the at-risk groups, that does not necessarily mean that strenuous exercise is off the table. After all, muscle growth is stimulated and strengthened by exposure to stress. Also, it is quite possible that you might never experience overexertion, if you work out within your comfort levels.
Here are some overexertion signs to watch out for:
Besides aching more than usual, overexertion sufferers may experience swelling and stiffness in the muscles, to the point of being unable to bend or move. An American Paralympian snowboarder realised something was wrong when she could not straighten her arm after doing dozens of pull-ups at an exercise class. She was diagnosed with overexertion when she saw her doctor.
The signs of dehydration include your eyes, lips and the inside of your mouth feeling dry. Sufferers may feel constantly thirsty, produce little urine (less than four times a day) and have spells of dizziness. They may even lose consciousness, due to decreased blood pressure from the lower blood volume caused by the body losing more fluid than taken in.
One of the Singaporean women who suffered rhabdo in the February spinning incident said that her urine took on the hue of Coca-Cola three days after the fateful class. Also described as “tea-coloured”, the darkened shade is caused by the body excreting the protein myoglobin through urine — after excess amounts are produced by the abnormal muscle breakdown.
The queasy feeling of wanting to throw up may be accompanied by fever, increased heart rate and even confusion. About half of all overexertion victims do not show muscle-related symptoms. So, if you do not feel well, play safe by consulting a doctor and letting him/her know about your recent exercise history.
“About half of all overexertion victims do not show muscle-related symptoms. So, if you do not feel well, play safe by consulting a doctor”.
Avoid repetitive movements
It is easy to overexert oneself by performing repetitive movements that strain the muscles over a long period of time. This include workouts such as long-distance running, cycling or spinning, swimming and lifting of heavy weights repeatedly. Vary your exercise routine or schedule regular breaks during your workouts.
Maintain your body temperature
Overexertion has a higher chance of occurring during hot weather with high humidity. While our bodies cool down when we sweat, the process may not function as efficiently in a very humid environment such as Singapore’s. Drink plenty of water to stay hydrated and check the weather outlook when scheduling your run or bike rides to avoid the hottest hours.
Don’t rush to push yourself beyond limits
If you have always led a sedentary lifestyle and are only starting to exercise, take things one step at a time. Go slow and build up your stamina and strength over several sessions. Likewise, if you are returning to exercise after a long break, do not expect to reach peak fitness instantly — you will need time to work your way back up.
Overexertion frequently occurs without the victim realising it, and many who overexert themselves during exercise make the decision to keep going despite the discomfort. Instead of powering on and putting your health at risk, you should:
Hydrate Drink before, during and after you exercise and stick to water — caffeinated drinks cause more frequent urination, which in turn can lead to fluid loss.
Seek medical advice See a doctor immediately if you experience any symptoms of overexertion. If left untreated, overexertion can lead to acute renal failure and compartment syndrome (a condition where restricted blood flow to an area of the body damages the muscles and nerves). In extreme cases, doctors have had to cut open the muscles of victims to relieve swelling and pressure.