Fatigue: The Double Agent

In our last post, Owen talked about his personal experience of how perseverance through a decline in performance ultimately led to ‘overtraining’. We are going to dig a little deeper and show you that there is a big grey area when it comes to overtraining.


Revision: Exercise causes a disruption to the body’s homeostasis resulting in an acute decline in performance. When given adequate rest, the body will recover and performance will increase. When we do not give the body adequate rest, this is where problems start to arise…

Firstly, don’t think that the second you get tired you are overtrained. Also, realize that there are a few intermediate steps before you develop Overtraining Syndrome (OTS). The level of ‘overtraining’ is categorized according to the time it takes to restore performance. Now for some new terms:

• Functional Overreaching (FOR): allowing fatigue to accumulate from consecutive training bouts, knowing they will be followed by a recovery period.  This can be recovered from in around a week.
• Non-Functional Overreaching (NFOR): Ignoring that recovery period when you have overreached. This can take up to months to recover from. If you continue to train, this will eventually lead to Overtraining Syndrome (OTS), which can take years to recover from.

Time to throw another spanner in the works. Studies have shown that endurance training and resistance training lead to different types of overtraining. Parasympathetic overtraining (thought to arise from endurance training) affects the hypothalamic-pituitary-adrenal axis and alters levels of cortisol, testosterone and catecholamines. Sympatheitc overtraining (thought to arise from resistance training) increases excitability and has been linked with restlessness and irritability.
 

Other symptoms of overtraining include:

-       decreased sex drive, loss of appetite, decrease in enthusiasm

-       alterations to resting heart rate, reduced sympathetic drive, reduced heart rate variability.

Hopefully you now realize that temporary declines in performance are the precursor to performance gain. Be careful because this decline in performance is a double agent. If you don’t watch it carefully, it can quickly lead to overreaching and eventually Overtraining Syndrome. In our next article, we are going to talk about ways to avoid OTS. Stay tuned!