Fitness professionals should recognize the signs and symptoms of overtraining, and help clients to recover from it, or prevent it in the first place.
The syndrome of overtraining in fitness and exercise programs is common in nearly all fitness centers. Overtraining is defined as training more than the body can recover from, to the point where performance declines.
One research study found that 64 percent of elite female runners and 66 percent of elite male runners have experienced overtraining in their running careers. Similar figures are found with bodybuilders, triathletes, swimmers and cyclists. Why this high occurrence? Many highly motivated exercisers are obsessed with training and afraid to rest. They believe that the harder they train, the bigger, stronger and fitter they'll become, despite evidence to the contrary.
Thus, many exercisers attempt to do more work than they can physically tolerate - to the point where the standard two to three days of light workouts or complete rest don't allow recovery. Many don't even know they're overdoing it until they reach the chronic phase of overtraining, where they grind to a halt and need several weeks of rest to recover.
Temporary overtraining such as increasing the number of exercise days in a week, for example, is referred to as overreaching. True overtraining is the condition where the symptoms of overtraining linger for weeks or even months.
Because of the problems with overtraining, one of the major jobs of a personal trainer is to make sure clients don't overdo their training - especially since the use of recovery as a training principle is undervalued and underused in exercise prescriptions.
Adaptation and progressive overloadFor improvement, well-designed cardio and resistance-training programs use the training principle of progressive overload: a constant and progressive increase in training stimulus. This is the only effective way to continually improve performance.
Here's how overload works: As exercisers increases their training workload (whether it's weights or distance), their bodies respond by adapting to this increased stress (often called supercompensation). Then they overload again, and their aerobic fitness, strength or skill improves to a new level. And, the process repeats itself.
Unfortunately, for many reasons, training volume and intensity cannot continue to increase in a linear fashion, and eventually exercisers reach a point where rest is not adequate enough for full recovery.
Proper conditioning requires a balance between overload and recovery. This is a fine line, indeed, as adaptation to a new training load varies from person to person, and day to day, depending on nutritional status, stress levels and myriad other uncontrollable aspects of people's daily lives.
Causes of and identifying overtrainingThe most common reasons for overtraining appear to be rapid increases in frequency, intensity or duration of training sessions, or a combination of those factors, without proper recovery. Collegiate cross-country runners who suddenly begin twice-daily workouts experience many signs and symptoms of overreaching or overtraining. Likewise, this happens with swimmers, cyclists and runners who increase the frequency of their interval-training sessions, compete in too many races or increase their mileage too quickly.
Fitness professionals can encounter problems identifying overtrained exercisers because many clients consider excessive ongoing fatigue a part of their normal training effort. Overtraining is difficult to diagnose because there's no simple test for it, such as a blood-chemical test, or a clinical diagnosis. In addition, people exhibit different symptoms, with no two being the same. Some studies, for example, have shown no difference in blood profiles between overtrained and non-overtrained athletes.
So, the best fitness professionals can do is to teach clients to recognize the general symptoms of overtraining, and then tell them to rest and recover. For a list of the symptoms of overtraining, see Table 1.
Systems affected by overtrainingWhat does science have to say about overtraining? Recent research suggests that it is a neuroendocrine disorder, primarily affecting the nervous and endocrine systems, which seems to match up well with the symptoms.
Other theories are that it's caused by excessive trauma to the muscle cells without adequate healing. This "catabolic-anabolic imbalance" theory holds that the overtrained body is dominated by a catabolic (or breaking down) state instead of an anabolic state, where the body regenerates itself.
The multiple signs and symptoms of overtraining particularly affect the muscular-skeletal, immune, endocrine, cardiovascular and nervous systems. The symptoms appear to be exacerbated by external stressors such as lack of sleep, jet lag, ongoing illness, work-related stress, poor nutrition, etc.
The magnitude of the effects of overtraining on the hormonal system cannot be overemphasized. This is because the body releases stress hormones such as adrenaline (epinephrine) to increase heart rate, shunt blood to working muscles, release glucose into the bloodstream and stimulate fat metabolism. And, overtraining causes abnormal responses in the autonomic nervous system through the excess production of adrenaline - which, in turn, suppresses the body's production of serotonin and dopamine (hormones that have a calming effect), causing people to experience the symptoms of depression and anxiousness seen in Table 2. Overtraining can also cause diminished sex drive and sexual performance, and fear of training.
Research also shows decreased bone marrow hemosiderin (abnormal microscopic iron oxide pigments that accumulate in the body) in overtrained runners, indicating hypocellularity (low cell production) in the bone marrow of the hemoglobin producing sites.
Other undesirable changes found in endurance athletes and bodybuilders are muscle fiber and mitochondrial abnormalities, and alterations in the genetic material of over-exercised muscle - indicators that the normal adaptation process has been suppressed by overtraining.
Another study found that glycogen depletion is common among overtrained runners because they fail to eat enough carbohydrates to match their caloric demands. Sports nutritionists note that this syndrome is widespread throughout all sports and fitness activities, whether on the track, in the pool or in the fitness center.
In addition, overreached athletes experience a higher oxygen uptake and heart rate at a normal training intensity. In other words, they breathe harder and their hearts beat faster doing the same work as it did previously. Chronically overtrained athletes often exhibit a reduction in sub-maximal and maximal heart rate at identical workloads done previously. For some reason, the overtrained athlete's heart's response to running is dampened with chronic overtraining. And, lactate levels are at higher concentrations at the same speed. This means that clients will feel worse and struggle more to perform at the speed that was formerly easy for them.
The immune systemResearch has shown that mild to moderate exercise actually boosts the immune system; but, overtraining precipitates many undesirable hormonal and biochemical side-effects that will grind the body to a halt and make a person sick. Overtraining causes a reduction in leukocytes (white blood cells) and cytokines (the body's infection fighters), and antibodies. This means that overtrained athletes have more chances of getting an illness or infection, and complications from these. Many studies show that heavily trained athletes catch colds easily - one study even found that, after an endurance event like a half-Ironman triathlon, a competitor is five times more likely to catch a cold than someone who trains without competing.
The role of glutamine has been investigated recently, as it is a precursor amino acid in the production of leukocytes. Low levels of glutamine have been shown to dampen the body's production of these white blood cells, which lowers immunity and increases susceptibility to viral infections. It's thought that glutamine supplementation could prevent this immuno-suppression, and could be used as a preventive or treatment countermeasure against overtraining.
One promising glutamine study found that only 19 percent of athletes who ingested 10 grams of glutamine after a marathon had symptoms of an upper-respiratory tract infection, compared with 51 percent of runners consuming a placebo. However, another study concluded that although glutamine supplementation countered glutamine loss after bouts of exercise on a bicycle ergometer, low glutamine levels have yet to be proven to cause a depression in the post-exercise immune system. Another conflicting study found that plasma glutamine levels in overtrained swimmers were no different than those in well-trained elite swimmers.
Studies on antioxidants such as vitamins E and C, substances that protect healthy tissues from free-radical damage and ensuing inflammation, are promising. Still, they are not yet conclusive enough to suggest supplementation of these substances for post-exercise recovery.
Recovering from overtrainingOnce overtraining symptoms have set in, time is needed for the body to rebuild in a process called anabolism. For athletes who have simply overreached for a few workouts, a cessation or reduction in training for a few days (three to five) may be all that is necessary. If they have been overtraining for several weeks, they may need 10 to 14 days of reduced training, at a 40 percent reduction in normal training load, to bounce back. This applies as much to weight training volume as to running, swimming or cycling volume.
Two to three weeks of rest is required for athletes who have overtrained with prolonged, grueling schedules lasting several months. For chronic symptoms from years of overtraining, reduction or cessation of training for a few months may be necessary, although this is relatively rare. Even rarer are cases when runners have needed one year to recover, although some are documented.
Fitness center applicationsThe first step to help clients avoid overtraining is to teach them how to self-monitor for the symptoms. Use the suggested recovery strategies in Table 3 for advice on how to do this.
The use of a heart rate monitor in endurance events has been used to assess whether the athlete is working harder than normal to achieve the same pace and distance, but it's just as helpful to use common sense. If clients are feeling exhausted, have them cut back on their exercise until they bounce back.
The real key to avoid overtraining is prevention. This should involve the use of periodized programs where one week of lower-intensity and lower-duration training every three to four weeks will permit adequate recovery of the muscle tissue and energy refueling. These are called macrocycles, and are the building blocks of creating a program that allows for recovery.