High intensity levels or large training volumes are often required for athletes to achieve gains in performance. However, training at high intensity increases the risk for injury and fatigue due to overtraining. Proper training requires a balance between overload and recovery. Inadequate rest and recovery or too rapid increase in training volume or intensity may result in overtraining syndrome (OTS). Additionally, emotional and psychosocial stress may contribute to developing OTS. OTS is a complex disorder that results in a deceased response to training and reduced athletic performance.
The most common symptoms of OTS are unexplained underperformance, persistent fatigue, loss of motivation, and sleep disturbances. Other symptoms include depression, irritability, lack of concentration, restlessness, decreased appetite, weight loss, and heavy, stiff, or achy muscles. OTS may also manifest as frequent injuries or frequent colds.
OTS is difficult to diagnose because there are no definitive diagnostic tests and symptoms are vague and similar to those seen in other diseases. The diagnosis of OTS is made based on the athlete’s history and by ruling out other causes of symptoms. OTS can be diagnosed when there is a decrease in performance and changes in mood that cannot be explained by other causes and do not resolve with two to three weeks of rest.
Some methods for recognizing early OTS are tracking heart rate and keeping a training log. An increase in resting heart rate of more than 10 beats per minute, taken upon first awakening, may indicate inadequate recovery and need for increased rest. However, resting heart rate is affected by many variables and cannot be considered definitive. A training log that documents physical and psychological responses to workouts can aid in recognizing downward trends in performance and changes in mood or motivation.
Another sign of OTS may be a reduction in heart rate variability (HRV). Heart rate increases slightly with inhalation, and decreases with exhalation. This variance in heart rate is known as HRV. Physiological stress has been shown to reduce HRV. This is due to overstimulation of the sympathetic nervous system which happens during anaerobic exercise. A return to pre-workout HRV indicates restored autonomic balance and full recovery.
VO2 max testing is another method for detecting OTS. A VO2c max test that shows decreased time to fatigue and decreased lactate production at maximal VO2 testing indicates poor exercise recovery.
The primary treatment for OTS is rest. Depending on the level of OTS, decreasing training intensity by 50 to 75 percent for one to two weeks may be adequate. For more severe OTC a period of light exercise or complete rest may be needed. A plan for returning to training should include a review of emotional stressors, diet, and sleep patterns. Recovery from OTC can take several weeks and returning to training should be gradual and carefully monitored. A full return to training and competition should be considered only after all physiological and psychological symptoms and signs of OTS have resolved.
Methods for preventing OTS include getting adequate rest and nutrition, and using periodization of training. A minimum of eight hours of sleep may reduce the risk of OTC. Proper nutrition reduces the stress response to exercise and glycogen depletion. Low levels of muscle glycogen can cause muscular fatigue and a decline in performance. Periodization strategies could include taking at least one rest day a week and alternating hard and easy days. If you experience signs and symptoms of OTS it's important to assess your training routine and make adjustments.
Ultrasound muscle glycogen level assessment and VO2 max testing are available at Scottsdale Sports Medicine Institute. Call for more information or to make an appointment.
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