Personal Experience

Parasympathetic overtraining is presented in many sources as having some of the following symptoms: early onset of fatigue, decreased resting heart rate, rapid heart rate recovery after exercise, and decreased resting blood pressure. This kind of overtraining is associated mostly with athletes who are highly aerobically trained, and who’s training load is at a lower intensity but a high volume. Many triathletes, marathoners, cyclists, and other endurance athletes who were diagnosed with overtraining also noted that they had difficulty getting their heart rate up into the training zone that they wanted to be in for a given workout. The heart just couldn’t pump fast enough.

Sympathetic overtraining on the other hand, is presented as having some of these symptoms: increased resting heart rate, increased blood pressure, loss of appetite, decreased body mass, sleep disturbances, and elevated basal metabolic rate. This kind of overtraining is associated with mostly with athletes who are highly anaerobically or who are highly resistance trained, and who’s training load is at a high intensity but a lower volume. Focusing on heart rate again, we notice that sympathetic and parasympathetic overtraining elicit completely opposite responses when it comes to heart rate – the heart rate is abnormally high with sympathetic OTS and abnormally low with parasympathetic OTS.

My specific problem with these presentations of the two types of OTS comes from my personal experience. I would not consider myself to be solely an endurance athlete, but my training this past year was very similar to one. I had a high volume (60+ miles per week of running as well as cross training) with a relatively low intensity most of the time. I did not lift regularly and I didn’t do much if any anaerobic work. I developed OTS because of my lack of recovery. Now, since my training was endurance related I should have the symptoms of parasympathetic OTS, but it is quite the opposite in regards to my heart rate response. I have tried going for runs several times over the past 6 weeks and on these runs I wore a heart rate monitor. Each time I would start out at a pace that was slower than my usual training pace and within minutes my heart rate was in the 150s – 160s, which is 78% – 83% of my max heart rate, and it would stay there until I stopped running and then it would gradually decrease (slow heart rate recovery). I also noticed that during my training my resting heart rate was in the low 40s, but now it is in the low 60s. These findings contradict the literature and have lead me to want to spend time comparing the two types of OTS.

 

Answer:

According to the article The Overtraining Syndrome by Dr. Philip Maffetone, OTS progresses in 3 stages. The first stage is “Functional Overtraining” and this can either be accompanied by slight decrease in training performance or a dramatic improvement in competitive performance (overreaching). The second stage is “Sympathetic Overtraining” and this is when neuroendocrine imbalances worsen and the sympathetic nervous system becomes overactive causing a higher resting heart rate (I might be in stage 2). The third stage is “Parasympathetic Overtraining” and this is the worst stage when chronic overtraining leads to “more serious hormonal, neurological, and mechanical imbalances (which continue to parallel adrenal dysfunction and aerobic deficiency)” (Maffetone, page 2). The sympathetic nervous system becomes exhausted and the parasympathetic nervous system takes over causing the reduced resting heart rate and rapid heart rate recovery. The important thing to note in this article is the idea that in endurance athletes (and possibly other sports) sympathetic overtraining occurs first, and if not taken care of progresses to parasympathetic overtraining.