When Exercise Goes Too Far

WHEN EXERCISE GOES TOO FAR

In consultation with Dr Benjamin Soh, Registrar, Sports & Exercise Medicine Centre, KTPH

High-intensity exercise is getting more popular as people seek more exciting and effective ways to work out. However, excessive exertion carries a small risk of serious muscle damage, known as rhabdomyolysis.

It is common to experience muscle soreness after rigorous exercise, especially if you are new to a fitness regime or have just increased the intensity of your workout. However, if your muscle aches are more severe than normal and accompanied by nausea, rapid heartbeat, and/or brown-coloured urine, it could be a sign of something more serious.

The condition is called rhabdomyolysis, a potentially life-threatening condition where damaged muscle breaks down and ‘leaks’ into the blood and urine.

Rhabdomyolysis can be caused by: • Traumatic injury: when a limb is trapped/crushed in an accident • Substance abuse: the use of illegal drugs and excessive alcohol • Strenuous exertion: which causes muscle cells to be depleted, causing them to die

HOW COMMON IS EXERCISE RELATED RHABDOMYOLYSIS?

Generally, most hospitals see only a few cases of rhabdomyolysis related to exertion a year; it is far more common to be caused by trauma. A study in military recruits undergoing basic training showed 22.2 cases per 100,000 per year, an incidence of only about 0.02%.

Even though the condition is relatively rare, it has come under the spotlight recently due to the rise in popularity of high-intensity workouts, including spinning. However, the overall risk remains low and should not discourage individuals from exercising.

WHO IS AT RISK OF EXERCISE-RELATED RHABDOMYOLYSIS?

In most cases, those who are less fit are more at risk, but it can still happen to anyone who exerts themselves too much — even elite athletes, although it is generally less common. Other risk factors include: • Exercising in extremely hot and humid conditions • Dehydration • Wearing clothes or taking medications that reduce sweating • Pre-existing medical conditions, such as poorly controlled diabetes or thyroid issues • Exercising when unwell (e.g. with a viral infection)

HOW IS EXERCISE-RELATED RHABDOMYOLYSIS TREATED?

Treatment depends on the severity of the condition, but typically consists of supportive care with lots of intravenous fluids to help flush the toxic by-products of the broken-down muscle tissues out of the body. In more severe cases, short-term damage to the kidney may occur, which will entail the need for additional medications and a short period of dialysis. Most people who have exertionrelated rhabdomyolysis have milder cases, and can be discharged from hospital in about a week, once blood tests have normalised. However, due to the

• Severe muscle aches • Weakness or swelling in affected muscles • Brown-coloured urine • Fever • Rapid heartbeat even at rest • Nausea and vomiting • Reduced urination • Confusion

However, not everyone with rhabdomyolysis will exhibit all these symptoms. If you are experiencing any of these, do not panic. Visit a doctor to get a confirmed diagnosis through blood and urine tests. muscle damage and death, it may take several weeks to months to train them back to their previous state.

WHAT ARE SOME STEPS TO PREVENT EXERCISE-RELATED RHABDOMYOLYSIS?

Most importantly, start slow and progress gradually if it is your first time doing a new activity, or if it has been a long time since you have exercised.

Being good at one type of exercise does not necessarily mean you will automatically be good at all types, so take several sessions to familiarise yourself and build tolerance to the specific exercises you are doing.

It is also important to prevent dehydration, as this is a big risk factor for rhabdomyolysis.

• Keep yourself hydrated during exercise with small sips • Avoid exercising under extremely hot and humid conditions, such as outdoors at midday • Wear light and nonrestrictive clothing • Avoid exercising if you are unwell • Do not exercise if you are taking cough and cold medicines, as these can reduce sweating • Do not exercise under the influence of alcohol

If you have any pre-existing medical conditions that you are unsure about, please consult your doctor for further advice.

RHABDOMYOLYSIS: SYMPTOMS TO LOOK OUT FOR

• Severe muscle aches • Weakness or swelling in affected muscles • Brown-coloured urine • Fever • Rapid heartbeat even at rest • Nausea and vomiting • Reduced urination • Confusion

However, not everyone with rhabdomyolysis will exhibit all these symptoms. If you are experiencing any of these, do not panic. Visit a doctor to get a confirmed diagnosis through blood and urine tests.