Atrophy and ensuing loss of strength and power from being immobilized (like in a cast) can be dramatic in only a short time.
Likewise, a simple cessation of training results in atrophy and loss of strength and power.
According to some studies, strength loss is relatively slow: but note that these studies typically are done on young, highly trained athletes - strength loss may be much faster in a person training for fitness. It is surmised that at least some of the strength loss resulting from detraining is caused by a disturbance of the neuromuscular connection. It seems that muscle recruitment becomes less efficient. Incidentally, it is thought by some that muscle strength, power, and size gained from training can be retained by very minimal training.
That would support the common prescription currently in favor to get rehabilitation going as rapidly as possible - even very low intensity exercise. This "fast start" technique is commonly used now both with highly trained athletes and the rest of us commoners. Immobility after an injury can lead to a rapid loss of strength, aerobic fitness, and flexibility.
Muscle Endurance
Muscle endurance decreases after just two weeks of detraining. It isn't clear whether this decrease is caused by cardiovascular changes or changes in the muscle itself. A change in oxidative enzymes [Remember that muscle endurance is largely based on aerobic (with oxygen) activity.] is one noticeable affect soon after the start of detraining. A decrease can be measured after only two weeks of immobilization. It takes a little longer for the glycolitic enzymes to decrease, hence anaerobic (without oxygen) muscle activity declines slower - about four weeks as opposed to two weeks for endurance activities.
The losses appear to occur faster in highly trained individuals. In a study of competitive swimmers versus a group of untrained subjects, the untrained group showed no loss of muscle glycogen (a significant energy source) after four weeks of inactivity, but the swimmers levels dropped to nearly the same levels as those of the untrained group. That makes eminent sense, since an untrained person doesn't have much glycogen storage to begin with. Also, a lot of the detraining effects on highly trained individuals is a result of loss of extra capillary development resulting from strength training.
Flexibility Loss
Decreases in flexibility occur rapidly during inactivity. Actually, this aspect of fitness needs constant attention, but especially during periods of detraining. But, on the up side, flexibility can be regained quickly. [My experience is that that isn't necessarily so, but I expect that it depends on the degree of flexibility before the start of detraining. Maybe there is even some genetic factor involved?] Cardiorespiratory Changes
In a 21 day study, subjects were given bed rest with very little activity. After the bed rest concluded, tests were performed which verified:
It seems that cardiorespiratory endurance decreases are much larger than muscular strength and endurance during the same time duration.
Studies have shown that conditioning can be maintained on a schedule of three training sessions per week. Less training leads to substantial loss of conditioning.
For aerobic conditioning, a suggested maintenance level is three days a week at 70% of normal intensity. A reduction in training intensity results in a more substantial loss in aerobic conditioning than from a reduction of either frequency or duration.
Retraining is simply the resumption of training after a lay-off. As previously stated, a highly trained athlete loses more training affects and faster than a less-trained individual, and takes longer to return to top form.
When joint mobility has been lost, reestablishing it becomes the first priority. This is true regardless of the cause.
Now that we have described detraining and retraining, let's add overtraining. How do you know if you are overtraining? It isn't always easy to identify, that's why it is called "over-training syndrome;" there are several factors involved. A commonly occurring symptom, however, is a decrease in performance; and very often an increase in Resting Heart Rate (RHR). Other symptoms are:
Overtraining can affect several of the body's systems, including the sympathetic and parasympathetic nervous systems, the endocrine system (hormonal responses), and the immune system.
Some nervous system responses in addition to those already mentioned are rapid HR recovery after exercise, and decreased resting blood pressure. Please note that both of these symptoms may be quite normal (expected, in fact) and not at all indicative of overtraining, making a diagnosis difficult.
Some additional nervous system symptoms of overtraining are:
The immune system's response is a suppression of normal defensive responses against bioterrorists like bacteria, viruses, parasites, or cancer cells.
Increased susceptibility to infections has been shown to be a frequent response to both intense physical activity (a hard marathon, for example) or overtraining - it isn't always clear which is the culprit. Interestingly, exercise can enhance the effectiveness of the immune system; but in excess, it can have the opposite effect.
To recover from overtraining can take days or weeks of reduced training intensity, or in extreme cases, complete rest (usually in the 3-5 day range).
To avoid overtraining, variations in intensities are recommended - mix hard-moderate-easy training days; and for endurance athletes in particular, carbohydrate consumption must be adequate to retain a constant glycogen (stored energy, essentially) supply.
Here is an update on CMV (cytomegalovirus) and its possible link to restenosis (narrowing of coronary arteries soon after angioplasty). If you remember, CMV was first mentioned in the MAF Fitness Newsletter back in October of 1997.
In October of 1996, the National Heart, Lung, and Blood Institute (NHLBI) in Rockville, MD identified a link between prior CMV and narrowing of coronary arteries soon after coronary angioplasty. In case you didn't read the earlier article, an angioplasty is a procedure used to widen clogged coronary arteries. In simple terms a balloon is threaded through an artery to the logjam, where the balloon is inflated to mash the obstruction against the artery walls, and thereby widen the highway. It is not uncommon for the newly widened area to begin to clog up within a relatively short time.
The chief of NHBLI's Cardiology branch, Dr Stephen Epstein, has stated that the presence of CMV significantly increases the risk of restenosis after an angioplasty is performed.
In addition to balloon angioplasty, other methods of attacking atherosclerosis are atherectomy (a procedure where a sharp blade literally cuts the blockage away), and the most radical procedure - coronary artery bypass surgery (CABG).
In 10-50% of angioplasty cases, the plaque (gunk that blocks arteries) grows back.
Why restenosis occurs isn't clearly understood, but Epstein has theorized that earlier infection by CMV has something to do with the phenomenon. To test his theory he studied 75 patients who had been found to have no CMV antibodies before or after an atherectomy. No active CMV was found.
A study by the NHLBI recently reported in the New England Journal of Medicine; however, showed that patients with higher levels of CMV antibodies prior to atherectomy had a noticeably higher rate of restenosis after a six month period than patients without CMV antibodies.
Epstein noted that 85% of the patients had combined atherectomy and balloon angioplasty, and therefore concluded that restenosis is probably not procedure-specific.
Interestingly, a possible conclusion was made that the procedure used for a heart patient might depend on the presence or absence of CMV - angioplasty if CMV is absent; CABG if CMV is present. The conclusion is still speculative, and additional study is required, but a new tool to prevent restenosis may be on the horizon.
It is interesting that CMV (part of the herpes family of viruses) is common in people, but is symptomless, essentially dormant, in people with normally functioning immune systems. It is thought that by age 35 roughly half of the population has been exposed to CMV; and that by age 60, 70% have been exposed. But it takes a depressed immune system, as from AIDS or drugs given during organ transplants (to prevent organ rejection) for the virus to become active. It should also be noted that both balloon angioplasty and atherectomy damage vessel walls and cause the formation of scar tissue which can cause atherosclerosis (narrowing of artery walls - restenosis). This is a normal response to an "injury" to blood vessels.
In an earlier NHLBI study, CVD DNA was discovered in restenotic lesions. Smooth muscle cells grown from these lesions also carried some CMV genes which indicated that CMV was present in vessel walls. A product of a CMV gene, identified as 1E84 (You are lucky, there will be no test for this subject.) was able to bind to p53. Remember from an earlier Newsletter that p53 is a protein that prevents cell proliferation - handy for something like cancer cells. But, it is suspected that the binding to p53 effectively cancels its benefits, allowing smooth muscle cell restenosis to occur.
The bottom line is that the CMV-restenosis link is strongly supported by scientific evidence, but not to the point where treatment of heart disease can be based on it without further study.
"Girl's" push-ups? Honestly, that's what they are called, even though in today's social climate that is almost an obscenity. Let's just call a push-up a push-up. For those who can't do the regular hands-to-toes push-ups, whether male or female, forget about the knees-to-hands version. Instead do what I have always considered "cheating," and that is to shorten the distance between your hands and toes by sticking your butt up. As a purist, I have always supported a "flat back" during a push-up - hips not dropped toward the floor or butt up high, but a straight line from your head to your feet. And that is still the goal, but the butt-up position is an OK starting point for anyone who can't manage the purist form (a.k.a. military push-ups).
No Pain, No Gain? You have probably heard that phrase relative to exercise. Many fitness professionals have disagreed with that catchy little phrase. Especially for fitness lifters. Of course the pain we are talking about is from fatigue, not injury. BUT, there is at least one valid application of the "no pain, no gain" concept - physical therapy, specifically rehabilitation of joints.
The most important aspect of joint rehabilitation is regaining full/normal range-of-motion (ROM). Let's use a knee replacement as an example.
Working on knee flexion (bending) and extension (straightening) will be the first priority, and will be a painful process, but the faster the knee can return to full ROM, the more successful the recovery will be. Unfortunately you pretty much control your own destiny according to how much pain you can tolerate.
Straightening your new knee will probably be most difficult, but probably most important. You want to achieve a full recovery to avoid limping, for one thing. A limp sets you up for more joint damage in other areas of the hips and legs. A normal prescription might include Gravity Knee Extensions, Short Arc Knee Extensions, Heel Slides, and Band Leg Curls, each done several times a day. The "how to" part will come from your physician or physical therapist.
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(Q) I am 64, am I too old to start an exercise program?
J.W., Santa Clara, CA
(A) It's never too late to start. We frequently hear about people at age 70 or 80 starting an exercise program with positive results. But sometimes the physical changes are minuscule. I like to see people (especially women) start regular exercise at an early time in their lives.
(Q) Is a deadlift a back exercise, or a glute/hamstring exercise?
G.I.J., Milpitas, CA
(A) Both, but the emphasis can be changed slightly. As you bend forward and then stand up, you will feel a strong contraction of the hamstrings and gluteal muscles, but the muscles of the lower back (erector spinae group) are also active. If you stand up in an erect position, or even with a slight backward bend, the erectors seem to do slightly more work.
(Q) I just read that I should ignore my scale - maybe even retire it to the garage. What do you think?
A.B., Redwood City, CA
(A) I have heard that comment a lot, but I don't agree 100%. It is just another glib half truth. If you are 50 or 100 pounds overweight (and the extra weight isn't from building a lot of muscle) you don't need a scale to tell you that some serious weight loss is in order; but a scale can tell you if you are starting to gain weight before it gets out of hand (again, not because you are adding lots of muscle). And you can use a scale to monitor the routine vicissitudes of your body weight.
Body composition testing is probably the best way to keep track of changing weight, but it isn't readily accessible, and its accuracy depends largely on the experience of the tester and the method. Even the highly rated method of underwater weighing has its weak points. One being the ability of the testee to exhale as completely as possible while underwater, not easy for many. Also, it is probably the least accessible method of them all. The skinfold method can be quite accurate, but is highly dependent on the skill of the one using the calipers. When all is said and done, maybe your eyeballs and a mirror, how your clothes fit, and a tape measure are the best tools for this job.
You can keep your scale, but don't obsess about the numbers it gives you. Be conscious of how you look and feel - that is if you care at all. I have been aware of many women [I acknowledge that this is not exclusively a female problem, but more often than not it is.] weighing 145 to 170 and more who were attractive, fit, and strong - and proud of it, as they should be.
(Q) Does St. John's Wort actually help fight depression as I have heard?
J.H., Los Altos, CA
(A) Maybe, but use caution before taking any of this stuff. An incontrovertible yes or no is not really possible right now. There is some evidence that it might help with relief of mild to moderate levels of depression, and without the side-effects of anti-depressant drugs like Prozac. It is thought that its effect on depression (if indeed there is one) is caused by an increased level of seratonin, a chemical in the brain that has a mood-elevating affect. But it is not well-tested, nor is it regulated in the U.S. It is treated as a prescription drug in Europe, but unregulated here as an herb. And what tests have been done have compared the smaller European doses to larger doses that are common in the U.S.
For anyone who decides not to wait for U.S. testing (potentially a period of years), the director of the American Herbal Pharmacopoeia, Roy Upton; suggests using products providing 1 to 2 milligrams of hypericin daily - St. John's Wort is also called hypericum, from its Latin name. Also, it should be prepared from whole crude extract of St. John's Wort, and harvested during the time it is blooming, to get the most value out of the plant as possible. It may be that ingredients in addition to hypericin contribute to the benefits of St. John's Wort.
If you decide to take St. John's Wort, discuss it with a physician first. It can react with other drugs or medical conditions, and depression itself is not a straightforward condition for anyone to treat on their own.
Another caution is to be careful about taking the weed, and exposing yourself to a bright sun. Some data on farm animals link it and sunlight with phototoxicity.
The preceding information has been extracted from the January 1998 issue of Tufts University Health & Nutrition Letter. It also states that if no results are seen after four weeks, it probably is not going to work.
(Q) This isn't a question, but I recently ran across this amusing thought and wondered if you might like to share it with your readers:
'Take things a day at a time; if you have one foot in yesterday and the other one in tomorrow, you are pissing on today." [Sorry for the "earthy" language.]
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