Cardiovascular exercise is commonplace today in a world obsessed with fitness and maintaining the right physique. Yet, until recently, too much activity has been relatively unheard of. The average consumer has repeatedly heard the positive connection between fitness and longevity. While the benefits of exercise are substantial, too much exercise might be too much of a good thing. Benefits of exercise include weight loss, cardiovascular strengthening, increased balance and agility, and a decreased risk of acquiring a metabolic disorder, such as type II diabetes. In general, exercise keeps an individual healthy and thriving. Chronic cardio, on the other hand, has been shown, perhaps, to do the opposite.

Chronic cardio refers to endurance training, such as a marathon or triathlon training, that keeps your heart rate elevated for a longer-than-recommended period. During regular cardio, hormone levels spike like cortisol when the heart rate remains elevated. Cortisol is the stress hormone that controls the stress response, blood sugar level, water balance, and inflammatory response. Running or other endurance exercises places severe stress and strain on the body. This causes cortisol levels to remain elevated for too long, resulting in weight gain, slowed healing, muscle fatigue, high blood pressure, and severe fatigue. These are the opposite of what the body should achieve through exercise. Instead, the practice should bring increased energy, weight loss, lower blood pressure, and cholesterol levels, and better cardiac function.

 Another unfortunate complication that can occur in extreme cases related to endurance training is rhabdomyolysis. Rhabdomyolysis, a rare condition, can be caused by numerous factors, including heatstroke, blocked blood vessels, a car accident, or intense aerobic exercise, such as marathon training. Unfortunately, this condition occurs from the rapid breakdown of skeletal muscle. Myoglobin is released into the bloodstream when muscles break down, which is standard in small amounts. Myoglobin stores oxygen in the muscles, but kidney damage can occur when it is released into the blood due to fast muscle breakdown.

 Usually, rhabdomyolysis, if caught early enough, can be treated in the hospital with intravenous fluids. However, more stringent interventions will occur if the kidneys have become damaged in severe cases. Rhabdomyolysis can spark the need for dialysis to help the kidneys function appropriately. Symptoms include muscle weakness, extreme fatigue, nausea, vomiting, dark-colored urine, and possibly a fever. These symptoms are relatively common and can mimic other illnesses. So, it is best to be assessed by a physician.

After reviewing this topic, it is up to the consumer to decide if endurance training is worth the risks. Numerous athletes have been participating in endurance sports for years without complications. Another exercise that is beneficial with lower risks is called interval training. Interval training focuses on short spurts of expending energy with intervals of recovery. This allows the body to adapt to the activity strain and the muscles and heart to recover quickly. Again, speak with a physician at Cura4u before altering your exercise regimen.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 2^nd, 2023.