By STEVE KPA, CPT
We all love to train. Moreover, we love to get better, physically. However, sometimes the lure of achieving the greatest level of fitness and performance presents the problem of taking on more than your body is ready to undergo. Sound familiar? Higher training volume, intensity, and frequency are the usual protocols for many who want to get stronger and faster — a principle known as progressive overload. Though it is a widely practiced concept, it can often be done haphazardly and the costs are often overlooked. This series aims to examine the consequences of hard(er) training: overtraining syndrome and CNS (central nervous system) fatigue.
What are overtraining syndrome and CNS fatigue?
Before delving further into specifics, it is important to note that every activity the body is put through is a stressor (i.e., eating, exercising). Stress is a necessary variable in physical growth and adaptation, but it demands a level of balance with rest and recovery. If this balance is lacking, stress overwhelms the body and leads to a decline in overall health. Naturally, the consequences and symptoms of each can and do overlap.
Overtraining syndrome is a ubiquitous term throughout the majority of athletic training circles. In short, it is a culmination of engaging in greater than usual physical demands that exceed the body’s ability to adapt and recover sufficiently. Coupled with mental stress, the signs and symptoms are physical, behavioral, and emotional, including:
- Washed-out feeling, tired, drained, lack of energy
- Mild leg soreness, general aches and pains
- Pain in muscles and joints
- Sudden drop in performance
- Decreased immunity (increased number of colds, and sore throats)
- Decrease in training capacity / intensity
- Moodiness and irritability
- Loss of enthusiasm for the sport
- Decreased appetite
- Increased incidence of injuries.
- A compulsive need to exercise
Mechanisms of overtraining syndrome
So what exactly causes overtraining syndrome? There are numerous hypotheses, but all deal with the imbalance between training volume/intensity and recovery. A simple example would be failure to adequately replenish glycogen stores via proper nutrition following frequent high volume training. In turn, muscles are overworked, quick to fatigue with each following session, and begin pulling energy from elsewhere — further stressing the body and starting a domino effect of problems.
Similarly, adrenal fatigue is another phenomenon that may result from all this chaos. Though mostly theoretical in the contemporary field of medicine, the logic driving the idea of this dysfunction is intense or prolonged periods of stress that overwork the adrenal glands. This, in turn, blunts and inhibits the release of stress hormones, the balance of which is imperative for regular functioning both physiologically and socially. For example, epinephrine (adrenaline) “increases the heart rate and force of heart contractions, facilitates blood flow to the muscles and brain, causes relaxation of smooth muscles, helps with conversion of glycogen to glucose in the liver, and other activities.”
In summary, overtraining syndrome is a result of multiple factors and variables that encompass both physical and mental demands that exceed the recovery capacity of the body.