Overtraining
occurs when runners stresses their bodies more than the bodies can handle. There are two
types of overtraining: Sympathetic and Parasympathetic. Most runners are
familiar with Sympathetic overtraining, because that is the type of overtraining
that is discussed in running books. However, Parasympathetic overtraining is
more serious and needs to be understood.
Our Nervous System
There are two components to our nervous system: The Sympathetic and the
Parasympathetic. Both components are in operation simultaneously, and they
balance each other. When we experience stress, our Sympathetic system becomes
dominate and causes our heart to beat faster to get more blood flow, our
breathing rate to increase to get more oxygen, our sweat glands to function to
cool us off, adrenal glands becomes active, etc. After the stress has passed, our Sympathetic system reduces
its effect, and our Parasympathetic system becomes dominate and helps us
recover. Our heart rate slows, breathing goes down, we stop sweating, etc. Our
Sympathetic and Parasympathetic systems have opposite effects on our bodies: one
to handle stress and the other to recover from the stress.
Overtraining
Runners overtrain when they have insufficient rest after their training, that
is, they don't completely recover from previous stress before they subject their
body to new stress. In doing this, they tax the operation of their Sympathetic
system, and certain symptoms occur which signal that overtraining is taking
place. The following list of sympathetic symptoms is from
http://www.grapplearts.com/Overtraining-Article.htm
Fatigue
Reduced concentration
Apathy
Insomnia and/or troubled sleep
Irritability
Depression
Decreased performance
Delayed recovery from training
'Intolerance' to training
Elevated morning rested pulse
Increase in injuries
Chronic muscle soreness
Weight loss
Frequent minor infections
Appetite loss
Decreased enthusiasm for training
The basic remedy for sympathetic overtraining is to give our bodies additional
rest. The additional rest might need to be complete rest, or it might need to be
a reduced activity level and/or cross training.
While this overtraining is going on, the Parasympathetic system is trying to
cause the body to recover from the stress, but its effects are overshadowed by
the Sympathetic system.
Now, suppose runners ignore the symptoms of overtraining and continue to
train at their high level of stress. Eventually, the Sympathetic system becomes
exhausted. The Parasympathetic system then becomes dominate and attempts to
cause the body to recover. The Sympathetic system isn't able to balance the
recovery, and the body recovers too much. This is known as Parasympathetic
overtraining. The web site linked above described it this way.
There is also
another form of overtraining, 'parasympathetic' overtraining, that is associated
with a decreased resting heart rate. This occurs because the athlete has been
overtraining for so long that his hormonal and nervous systems become exhausted.
This is fairly rare for martial competitors and really only occurs [in]
endurance athletes with extreme training volumes.
Web sites I've studied give three symptoms of Parasympathetic overtraining:
resting heart rate goes down, quick recovery from stress, such as recovery time
between intervals, and no sleep disturbance. Notice that these symptoms are
symptoms of recovery.
Am I suffering Parasympathetic
overtraining?
If runners experience a drop in their resting heart rate or fast recovery
times, they aren't necessarily suffering Parasympathetic overtraining. They may be
experiencing the effects of a stronger body. How can they identify, then, the
cause of the changes in their bodies?
Parasympathetic
overtraining results when the Parasympathetic system becomes
dominate due to the Sympathetic system ceasing to function properly. So, lets
list the events that likely will have occurred when Parasympathetic overtraining
occurs.
Symptoms of Sympathetic overtraining occur. These are the symptoms that are
usually discussed in running books. The major ones are listed above.
These symptoms are ignored, or at least not compensated for adequately, and
the Sympathetic system becomes exhausted and ceases to be the dominate component of our nervous system.
The Parasympathetic system becomes dominate and puts our body into recovery
mode. Because this recovery is not balanced by the Sympathetic system, the
recovery goes too far, so to speak, and the resting heart rate decreases,
and/or recovery times are decreased.
Each runner, who is experiencing parasympathetic symptoms will have to decide if
he/she is suffering from Parasympathetic overload or is experiencing the effects
of a stronger body. It seems to me that the key observation is whether #1 and #2
(given above) have occurred.
gives an interesting symptom of overtraining that affects athletes who really
train hard.
Most recreational athletes are
more used to the notion that an elevated heart rate is the sign of overtraining,
specifically during rest, and they’re right in their thinking. Fewer athletes
are aware of, or ever experience, a heart that cannot beat fast enough. But
professional triathletes are very aware of this phenomenon, especially those who
engage in Ironman-style training and racing.
"There are days that I just can't
get my HR to the zone I want it to be in," says Ironman and World Champion Karen
Smyers. "This is a sign of not being recovered, and I reschedule the hard
workout planned for that day. If you recognize it early, you can usually recover
in a day or two. If you have pushed through it for a long time, you may need a
much longer time to pull yourself out of the slump." Every triathlete who has
done the big miles can relate to a time when the heart for some reason won’t
beat fast enough under load. What is in question is exactly why this happens and
what the physiological mechanism behind it might be.
The article gives the advantage of having a heart rate monitor.
"You won’t know you’re
heart-tired without a heart rate monitor," [longtime
American pro Mark]
Montgomery says. "You feel OK, more or less, it’s just that you’re out there
doing an amount of work that should have you up to 150 beats, but your heart is
only at 125. Your heart rate monitor is the only way you’ll know it."
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Web sites I've studied give three symptoms of Parasympathetic overtraining:
resting heart rate goes down, quick recovery from stress, such as recovery time
between intervals, and no sleep disturbance. Notice that these symptoms are
symptoms of recovery.
