NerveExpress

Although this technology has been around for 20 years, used for medical purposes and by medical professionals, it is relatively new in the exercise community. Ironically, this is one of the most vital pieces of equipment a person can own, since it helps to answer that all important question: "Am I overtraining and/or training hard enough?"

The I.A.R.T. research and testing facility now uses NerveExpress technology, best described as a fully automatic, non-invasive computer-based system designed for quantitative assessment of the autonomic nervous system (ANS) and general state of health based on heart rate variability analysis. What this technology does is compare the communication between the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS) of the ANS, the former of which is concerned with regulation under stressful conditions, whereas the latter is concerned with regulation under restful conditions. In other words, and among other uses, the NerveExpress system measures variability in heart rate intervals between rest as opposed to activity (e.g., of lying supine to standing up), or the transitional period between rest and activity as the SNS and PSNS attempt to counter one another to sustain homeostasis of the body. This is a valid means of measurement as established through the American College of Cardiology since it provides a cardiovascular response measurement that is critical in evaluating a person's health (i.e., physical fitness, wellness, functional capacity).

The validity of the Nerve Express technology has been established through three research studies at Columbia University. In sum:

"RR variability (quality and quantity specifics of intervals between R waves of heart activity) has been used for many years as a laboratory tool to evaluate the autonomic nervous system in short term experiments. The CHRONOS algorithms for computation of RR variability were developed at Columbia University under the direction of Dr. J. Thomas Bigger, Jr. in collaboration with Dr. Jeffrey N. Rottman while he was at Children's Hospital in Boston, MA and Washington University in St. Louis, MO. CHRONOS has become a gold standard, for the computation of RR interval variability for prediction of death and arrhythmic events in coronary heart disease and for physiologic and pharmacologic studies. The results of the comparison of the Nerve Express algorithms with the CHRONOS algorithms indicate that the results obtained are similar and suggest that the Nerve Express algorithms should predict death in coronary heart disease and level of physical fitness.

The reason measurement of heart response to rest and activity works so well is that it is known that autonomic response is the first human response to any intervention (stressor) whether physically or mentally based. A brief review of Hans Selye's ground-breaking book The Stress of Life will clarify and support this contention. Therefore, by measuring responses of rest vs. activity (even if that activity is very light), it is possible to determine a person's health status, including fitness level. This is important since if a baseline can be established (viz., when a person is not pushing his or her training to the limits and feels at ease mentally and physically* then the following can be measured and determined over a time line:

• Whether a person's physical fitness is improving or worsening, the latter of which may be the result of too much activity or other stress factors combined (e.g., fighting with a spouse, loosing a loved one, etc.). Lack of improvement could mean having reached one's peak in conditioning, but more often means deficiency in pushing one's limits.
• When to push one's limits in the gym and when to back off.

(The NerveExpress system offers far more than what is discussed here, but this is one of the more relevant applications for fitness professionals and strength and conditioning coaches.) In regard to the second point, it is an issue of over-reaching as opposed to over-training. When an athlete decides to take his or her training to the limits, what will be measured and shown through NerveExpress is a decline in physical fitness, which is not a bad thing. The idea is to train so hard that physical fitness begins to decline and then back off (when the athlete still senses a state of well-being and with only a modest decline) to achieve an adaptive rebound effect of improved conditioning. Training then resumes when fitness status is at least where it was or (hopefully) even higher, as determined through the NerveExpress system.

This was almost impossible to measure and graph before the advent of NerveExpress, since cycling training demands was based primarily on feel, and anticipating that a state of over-reaching would not result in over-training, since one stage easily and quickly can result or merge in the other. With NerveExpress, the athlete may still feel fine, but as there is a decline in status, and the degree to which this status can be measured and viewed, it now is possible to back off by warning of an objective measurement for 1-2 week recovery periods to allow for adaptation and improved function, all based on one's patterns of response held within a consistent environment (tested the same time of day and relative to when workouts occur, etc.). If the athlete does not show improvement, or has not returned at least to the level from which he was tested at his previous peak, more recovery time would be needed.

Let's look at an example of a competitive athlete, his initial test, conducted about one week after his final strength training bout at the IART facility, when he was well rested with minimal activity. The Fitnogram chart (PDF download) shows this person being at a fitness status of 12/6. This is what the numbers mean, as a result of an Orthotest (the effects of lying supine and then standing up): The vertical axis refers to the level of adaptation reserve, of how quickly and how well the body adapts to the transition of complete rest (lying down) to activity (standing up). A score of 1 is perfect and would belong to an athlete with superior conditioning and youth. The horizontal axis represents the functioning of the physiological systems, of how well the SNS and PSNS are working in general and with each other.

This quick test is followed up by another quick test that measures and analyzes the autonomic status of normal vs. deep breathing during the Valsalva Maneuvre (regular and deep breathing are compared before and immediately after the holding of one's breath while bearing down). Again, we look at this athlete's initial test results in this PDF graph. In this chart, what we are comparing is the autonomic balance between the SNS and the PSNS. In short, and although it is more complex than this, the more the result merges into the top right corner, the better (although people with unusual physiology and training, such as deep-sea diving, will have an increased PSNS and will have results that fall in the bottom right corner of the graph). People who are very distressed (e.g., overtrained, drug/alcohol use, etc.), will fall into the top left corner of the graph, whereas those with chronic illness (e.g., cancer) and the very old will dip into the bottom left corner of the graph. Both his normal breathing and deep breathing are at the same point (hence, only one dot can be seen on the graph).

The objective was to achieve a base-line, or benchmark of this subject's wellness and conditioning, but that did not occur. On the day that he was tested (December 28, 2006), the following was experienced beforehand and during testing: strept throat and the taking of penicillin and other combatant drugs and other minor mental and physical stressors that added up to a much larger problem. Consequently, this person's adaptive responses and ANS functioning were well below normal. We expected him to be, at the least, mid-average or above average in response, because of his former training and conditioning. However, we did not expect the involved stressors.

Nonetheless, this is the interesting point: This athlete expected to test much better. Although he knew he was not at the top of his game, he felt 'pretty good.' Now, consider how easy it is for an athlete (or your average trainee) to feel pretty good,, only to overtrain within a few more sessions, to have declined considerably in wellness and health status without warning and before the 'crash.' His experience indicates clearly that thinking one can still train or that one still feels within the norm can be far from the truth, thus making the NerveExpress technology an indispensable part of an athlete's training, but also for average folk in gyms and fitness studios who are trying to achieve more than mediocre results.

Although we do not have a baseline for this athlete at this point, it should be achievable within the next few weeks and into early January 2007. Once determined, the objective will be to test him immediately before each training session (or at regular interals not too far apart), since they will occur on the same days, at the same times, and be apart from his training days (one day recovery) every time (he will be tested only every two weeks prior to his trip abroad in February, since he will undertake only 6-7 sessions before the layoff). In other words, testing parameters will be consistent. Therefore, if his patterns of fitness show positive or negative changes, adjustments can be made in the total demands of his athletic training and strength training.

Also note that this athlete's is training toward a major competition in 2007; his chances of coming in peak condition and more powerful than his competitors is far more likely. He placed very well two years running, barely missing titles both times. This year he vows to be a completely different competitor.

Previously it was stated that NerveExpress offers far more than what is mentioned in this brief overview, and that the interpretations of the graphs are more complex than presented here. For more details, I encourage the reader to visit www.NerveExpress.com and download the Theoretical Review PDF file to learn all that can be done. For instance, fitness professionals can establish unique testing based on specific applications. As an example, you can compare the stress response and recovery ability of different exercise protocols, to determine which has a more stressful bearing on a subject. Greater or lesser demands may be appropriate, relative to an individual's needs, and this is how it can be establishd. The responses then can be correlated to the results (muscle gain, strength gain, fat loss, etc.) to establish further an ideal direction for a client, thus making the fitness professional a true investigative researcher.

If you lack background into the study of cardiology, some of the text may be a bit heavy in reading. However, much of it is simplified enough so that any fitness professional can make use of the general applications, particularly once you get your hands on the system and play around with it. Once you do, you will become aware that determining recovery and optimum performance was simply hit and miss in the past, whereby now you have an objective means to measure physical change and adaptation. And that is what exercise science is all about.

*A general sense of well-being is necessary since any type of strain can affect results, such as alcohol consumption, nervous tension, infection, etc. Moreover, since stress has a general effect on the body, it can be determined whether exercise is too extreme or if other factors are affecting recovery and physical fitness status. In effect, if exercise is not too demanding (nothing out of the ordinary or not as extreme as it was in the past), and yet fitness status is declining or is lower than usual, then factors outside training are responsible and steps need to be taken to rectify personal issues and/or a brief layoff implemented.