Many health clubs and personal trainers test clients to evaluate their fitness, prescribe training programs and evaluate the effects of an exercise program to see if there has been progress. Thus, testing is an important part of their service.
Procedures have been developed that are safe and provide good information, if done properly. If not, then injuries may occur, as was the case with a 65-year-old client in a health club who was injured while performing a series of exercises to estimate his strength. The client was the plaintiff in which the personal trainer and the club were named as the defendants. I assisted the attorney representing the plaintiff.
The client had a heart attack three years before the incident and had an arterial stent put in two years later. He also had a history of back problems 5-6 years earlier. Therefore, he should have been considered at high risk for heart and back problems; this strongly suggested that a conservative, prudent approach should have been used when doing strength tests.
One way to determine strength is to ask clients to lift a weight. If they can, then they are given a heavier weight. This continues until they cannot lift a weight more than once. This is considered the maximal strength of the muscles involved in the particular movement (for example, the chest or bench press). While this procedure is appropriate for weightlifters and is what they do in training and competition, it is not suitable for testing the average person and especially not for the older person, for those with joint problems, or for those who have heart disease or are at high risk for a heart attack. When a person lifts a heavy weight, there is a tendency to take a deep breath and hold it while pushing in order to stabilize the chest. During this strong contraction, the blood pressure rises markedly and the heart has to work harder to try to pump blood through blood vessels that have been closed by the contracting muscles surrounding them. It is like putting a nozzle on a hose. At the same time, there is so much pressure in the chest that blood is blocked from returning to the heart from the rest of the body. As a result, the heart has to work harder at the same time that it is getting less blood and oxygen. This may trigger a heart attack, as occasionally happens when people are shoveling snow or dragging a deer that they shot while hunting.
Fortunately, there is another way to estimate maximal strength. It is based on the linear relationship between the number of times a given weight can be lifted and the percentage of what can be lifted only once. As shown in the figure below, if a man can lift a weight ten times, then that weight is approximately 70% of what he could lift one time. If he lifted 70 pounds ten times, then his estimated maximal strength is 100 pounds.
The general procedure is as follows. The person administering the test estimates how much a client can lift 12-15 times. This can be based on what the person lifts while working out or using some norms for the person's age and body size. After the client lifts the first weight, the tester can estimate how much weight the client should try the second time. Because the estimate of maximal strength is more accurate if the number of repetitions is less than ten, selecting the proper weight for the first and second tests is important. It is not necessary to go to a weight that can be lifted only 1-4 times because this will be more difficult and has a higher risk of problems.
In this case, the plaintiff came to the club to begin an exercise program. The person who normally did the tests was not available, so a younger, less qualified personal trainer was asked to do the tests. It was not clear from the depositions how many testing sessions the personal trainer had done beforehand but he had no educational background in physical education, no courses on exercise testing and only a few instructional sessions in the club on basic principles of testing and training. While this usually would not be a problem when testing young, active and healthy men and women, it could be a problem in older, sedentary people with medical problems.
The injury occurred during the leg press exercise, where the client was seated and pushed against a weight while the back was supported. The American College of Sports Medicine recommends that 50-66% of body weight should be used for tests of the lower extremity. In this case, the client weighed 190 pounds, so the first weight should have been 95-125 pounds. The client had also mentioned to the personal trainer that he lifted 110 pounds during his workouts before he stopped exercising one year before, so this was a good starting weight. Based on how many times the client could lift the initial weight, more weight would be added in the second trial. If the client lifted the initial weight 12-15 times, the typical increase would be about 25-33%. However, because of the final weight used, I estimated that the increase had to be around 100%. The client remembered lifting the second weight about 8-9 times. During this second test, the client complained that his knee and back were sore. During the third test, the client was able to lift the weight about 4 times but complained of pain in his lower back. Several days later, he had more pain and was diagnosed with a herniated disk. He later went on disability.
Based on the fact that the personal trainer estimated that the client's maximal leg press strength was 495 pounds and that the client remembered doing 4 lifts, both the expert for the defendants and I estimated that the third weight was around 400 pounds.
When comparing strength of people of different sizes, the usual way is to use the measure of weight lifted divided by body weight. In this case, 400/190 = 2.10. Typical values that place a man in the �superior� category is 2.13 for men aged 20-29 years and 1.60 for men aged 60-69. The estimated �maximal� strength would be 495/190 or 2.60. Thus, the client was asked to do the highest level for young men and way above that of men his own age. However, considering the high level of estimated strength in an older man who was sedentary and wanted to begin exercising again, it is hard to believe that these numbers really reflect what was done.
The personal trainer who administered the strength test did not write down how much weight was lifted in the first, second, or third trials, only the final estimated maximum. When asked months later, he did not remember how much weight was used.
My deposition lasted 7 hours, during which the attorney for the defendants attempted to dispute my testimony. However, given 1) the lack of qualified instruction or supervision of the personal trainer, 2) the lack of information from the personal trainer about what he did and, more importantly, why he did what he did, as well as 3) the basic agreement by the expert for the defense on the final weight lifted and other facts, the attorney was not successful.
Three days before the trial was to start, attorneys for the plaintiff and the defendants settled the case out of court in favor of the plaintiff.
James Skinner, PhD specializes in the field of Exercise Physiology and is a Professor Emeritus, Department of Kinesiology at Indiana University. A former president of the American College of Sports Medicine (ACSM), he is one of five investigators of the HERITAGE Family Study on the role of genetics in the response of cardiovascular disease and diabetes risk factors after training. He received the 2014 ACSM Honor Award, the highest award in his field. In 2011, he received the Doctor Honoris Causa from Semmelweis University in Budapest, Hungary.
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