Dear Dr. Sankoff,
I have recently found myself in a state of overtraining and, among other symptoms, my resting heart rate in the morning was elevated to about 50 bpm from the usual 40-45 bpm. However, during the same period, my resting heart rate during the day (sitting at work, for example) remained at its usual value, sometimes dropping to below 40 bpm. I found these contradictory and was wondering if you could offer me an explanation.
Thank you,GustavoMiami, FL
The short answer: Over-training may be manifested by a change in resting heart rate, although this is as yet unproven. Nonetheless, it is probably best to assume that this is the problem and act accordingly.
The long answer: Over-training may occur in athletes who rapidly increase and sustain training volume or in those who maintain volume without adequate rest over a prolonged period of time.
Recovery periods have long been recognized as important to a balanced and effective training strategy. Recovery actually enhances performance both by allowing for adaptation to the increased volume of training immediately preceding it and by preventing over-training. When omitted, the ability of the body to maintain itself and continue producing performance at a sustained rate is impaired.
Over-training may manifest in a myriad of ways: Mild leg soreness, general aches, fatigue, lack of energy, a sudden drop in ability to swim, bike or run normal distances or times, insomnia, headaches, inability to relax, lowered resistance to common illnesses (colds, sore throat, etc.) and an increased resting heart rate (RHR).
The use of an observed increased RHR as a warning or a sign of over-training is based on experience with high-level athletes. However, hard evidence is lacking regarding the validity of RHR as such a predictor. Nonetheless, RHR may still be used in this way with the understanding that it is not foolproof. Athletes should listen to their bodies and watch for any of the signs of over-training, even in the absence of a change in RHR, and respond promptly.
RHR should be measured soon after waking up. Having an empty bladder is important, so it is best to get out of bed, use the bathroom, return to bed, wait about 30 seconds and then take your pulse. When following trends in RHR, an increase of 10 percent that is maintained over time should be interpreted as a sign of potential over-training. The fact that this increase is maintained is more important than one or two random readings. Generally, three successive days of increased RHR should be taken to reflect a true change.
Regardless of the signs or symptoms, over-training should be taken very seriously. An immediate, significant decrease in training volume and intensity is mandated and should ensue. Depending on the severity of symptoms, a complete cessation of training may be needed. The duration of this decrease or cessation will depend on the severity of symptoms and also on factors relating to previous fitness and to the athlete him/herself.
While the recognition and treatment of over-training are important, emphasis should really be placed first and foremost on prevention of this problem. This can be accomplished by the following:
* Modification of training schedule to include sufficient periods of rest and recovery
* Ensuring adequate sleep
* Maintenance of good nutrition
* Inclusion of massage and/or thermotherapy in your routine
Returning to Gustavo's specific question regarding the inconsistency in his HR change, it is important to realize that HR is affected by many different factors principally related to the nervous system. During the day our nervous system modulates the heart rate in order to meet the changes in demand brought on by our activities. Emotional issues may have an impact. This is the reason that RHR is measured in the morning immediately after waking up. Because the body is in a state of complete rest and the mind has yet to become fully active, the HR at this time is most representative of the underlying state of the body. Because so many other factors are at play over the course of the day, Gustavo's unchanged HR at the office is less important prognostically than is the 10-percent change in his RHR observed after waking up. The bottom line though, is that given the change in the RHR in conjunction with the other symptoms that he alludes to, Gustavo must take this as a sign of over-training and take the necessary steps both to recover and prevent this from occurring again.
Train hard, train healthy.
Dr. Jeffrey Sankoff, MD, FRCP(C), is a two-time Ironman triathlete and ER physician based in Denver, Colorado. To learn more, visit Sankoff's Web site.
If you have a question for Dr. Sankoff, please e-mail Triathlete Magazine Interactive. Please include "Dr. Sankoff" in the subject line.