Physical exercise is essential to maintain a healthy lifestyle, but there is a fine line between pushing oneself to the limit and overtraining. While a dedicated workout routine yields numerous benefits, overtraining can take a negative toll, and in some cases lead to potentially life-threatening outcomes.
One such condition is rhabdomyolysis, also termed rhabdo. Rhabdomyolysis occurs when, due to overexertion, muscle tissue breaks down and releases proteins such as creatine kinase (CK) and myoglobin that can damage the kidneys. Symptoms of rhabdomyolysis can include muscle aches; significant weakness; dark, murky urine; and, in severe cases, decreased to no urine output.
“Exertional rhabdomyolysis can occur after strenuous exercise and from high-intensity workouts during which the muscles are overused,” said Niloofar Nobakht, MD, associate clinical professor of nephrology. “You can also get rhabdo from direct trauma, such as a crushing injury from a motor vehicle accident or a fall.”
While anyone can get rhabdo, athletes, runners and people in certain occupations are at higher risk, Dr. Nobakht said.
At-risk groups for rhabdo include:
- Athletes
- Firefighters
- Police officers
- Military service members
Treating rhabdo
Patients with rhabdomyolysis may experience kidney failure and require dialysis. But, Dr. Nobakht says, the condition is manageable with prompt intervention.
“We might start with an IV fluid and closely monitor electrolytes such as potassium, phosphorus and calcium. Potassium and calcium are the two main electrolytes that play a significant role in recovering muscle function,” Dr. Nobakht said. “As nephrologists, our role is also to keep a close eye on fluid replacement, along with electrolyte and acid-base balances, in patients with rhabdo. Elevated blood acid level is a marker of malfunctioning kidneys.
The physiology of overtraining
Overtraining occurs when the body is subjected to excessive physical stress without adequate time for recovery. Initially, exercise-induced stress can stimulate the body's adaptive response, leading to improved strength, endurance and physical performance. However, prolonged and intense training with inadequate periods of rest disrupts this delicate balance.
Liz Au, FITWELL coordinator at UCLA Recreation, said the lack of a sufficient rest gap between exercise bouts can lead to overtraining and possible muscle breakdown, depending on the individual and the intensity of the exercise.
“The imbalance of training and recovery leads to negative physiological impact,” Au said. “Overtraining syndrome is actually a medical diagnosis, but there's no single test for it. It can, and will, disrupt normal body functions."
Negative effects of overtraining
Overtraining can result in imbalances in hormones such as cortisol, testosterone and growth hormone. These imbalances can adversely affect metabolism and muscle growth. In addition, the strain on the body due to overtraining can suppress the immune system, making individuals more susceptible to infections, illnesses and prolonged recovery periods.
Other symptoms of overtraining can include decreased performance. Rather than achieving the desired outcome, excessive training without adequate recovery can lead to fatigue, decreased strength and endurance. Overtraining can also negatively affect mental health, causing symptoms like irritability, anxiety, depression and poor sleep quality.
“Overtraining can bring about a slew of symptoms, and the key to preventing overtraining is to listen to your body, pay attention to signs of fatigue, persistent soreness or decreased performance,” Au said “Rest and recovery are essential components of any training program.”
Preventing overtraining and promoting optimal fitness
Au said there are several ways to proactively make sure you’re not overtraining. Some strategies include:
- Plan adequate rest days: Incorporate regular rest days into your workout routine to allow your body to recover, repair and adapt.
- Employ periodization: Periodization involves varying the intensity and volume of your workouts over time. This approach helps prevent overtraining by providing structured periods of active recovery.
- Prioritize sleep: Quality sleep is crucial for the body's recovery and repair processes. Aim for seven to nine hours of uninterrupted sleep each night.
- Nutrition and hydration: Properly fueling your body with a balanced diet and staying adequately hydrated are essential for optimal performance and recovery.
“Getting exercise is important, but to do it safely, we have to use safe training practices: Drink plenty of fluids, get out of the heat, perform gradual increments in exercise intensity and rest,” Dr. Nobakht said. “The key to being optimally fit is in finding harmony between challenging our limits and respecting our body’s need for rest and recovery.”
