by Arnie Baker, M.D.
You are feeling that you don’t have the power in cycling that you think you should. Or you feel that it takes you longer than usual to get going, if you can get going at all. Or it takes longer to recover from training or racing. This doesn’t seem to be a temporary set-back. It’s been going on for more than two weeks.
This article will present an overview of possible explanations, with an emphasis on medical problems you may want to consider in consultation with your doctor.
What’s Going On? Why Am I Riding So Poorly?
There are several possible explanations:
- Training errors
- Physiologic responses
- Medical problems
- Psychological problems
- Perceptual problems
- Ability or aging problems
Sometimes no specific problem can be identified. When no specific problem is identified, some physicians or coaches diagnose an ability or aging problem. I am often uncomfortable with this explanation because there is no way to test whether this diagnosis is correct.
Common physiologic situations resulting in decreased performance include sleep disturbances, caffeine withdrawal, drug use including alcohol, too rapid weight loss, and inadequate nutrition.
These are often treatable and are reasonably common, especially in Masters (older) athletes. Some may be associated with symptoms—for example environmental allergies or exercise-induced asthma. Many may not have any symptoms apart from riding poorly. Some sophisticated athletes are aware of problems because they use heart rate or power monitors.
Persistently high, low, or erratic heart rates may signal a cardiac or other problem. Power meters may not only document decreased overall power, they may show diminished power in one leg. Unilateral changes may be noted in single-leg exercises or by power meters that can differentially record power output from each leg. Such unilateral power loss may signal a nerve or vascular problem of the affected leg.
Some problems can be uncovered by a doctor’s office visit: an interview and physical examination. Other problems are not associated with specific symptoms or physical abnormalities, but can be looked for by simple blood or other testing.
Although I generally don’t expect to uncover the following medical problems, they are easy to check for and potentially dangerous to miss.
- Anemia, ruled out with CBC (complete blood count) blood test
- Diabetes, ruled out with a blood test
- Hypothyroidism (low thyroid), ruled out with a TSH (thyroid stimulating hormone) blood test
- Rheumatologic diseases, including polymyalgia rheumatica for older riders, ruled out with an ESR (erythrocyte sedimentation rate) blood test
- Liver infection (hepatitis) or disease, ruled out with liver function blood tests
- Kidney disease, ruled out with renal function tests
- Blood cancer (leukemia) ruled out with a blood test
- Electrolyte abnormalities, including low blood sodium, ruled out with electrolyte blood tests
- Coronary artery heart disease
In the general population heart disease is generally suspected on the basis of chest discomfort or pain. In Masters (older) athletes a decrease in power may be the only warning indicator; chest symptoms may be absent.
It is reasonable to have a maximal stress test (EKG). A maximal stress test is a ramped power test, to your maximum level. Many labs performed tests only up to 85% of age-predicted max. Since many athletes have true max heart rates considerably above age-predicted max, tests to 85% of age-predicted max may miss otherwise easily diagnosable heart disease.
Relatively few labs will perform exercise EKGs with bicycle ergometry—most test with a standard treadmill. Treadmill tests are okay as long as you get your heart rate up to at least the levels at which you bicycle. Otherwise, a treadmill test may fail to uncover this problem.
Less Common Medical Problems
Other medical problems occasionally surface. Generally symptoms, physical examination, or other blood tests point to these problems. If these problems are not suspected, they can be difficult to uncover. The following list is by no means inclusive.
- Joint diseases including osteoarthritis and rheumatic arthritis
- Spinal and peripheral nerve disease, including spinal stenosis and herniated discs
- Infectious diseases including mononucleosis, HIV, Lyme disease, syphilis, and chronic low-grade intestinal infections
- Other collagen vascular or rheumatologic diseases including systemic lupus erythematosis and scleroderma
- Other endocrine problems such as adrenal insufficiency or parathyroid dysfunction
- Plasma cell disorders including multiple myeloma, macroglobulinemia, amyloidosis, and heavy chain diseases
- Heavy metal poisoning (arsenic, cadmium, gold, lead, ,mercury, thallium)
- Cancers including those of the breast, lung, colon, and lymph glands
- Non-vascular heart disease including valvular heart disease, myocarditis and pericarditis
- Pulmonary hypertension
- Vascular insufficiency (blood vessel blockage) of the leg arteries due to atherosclerosis or by hypertrophied muscles
- Neurological diseases including multiple sclerosis and those caused by vitamin and lipid abnormalities
- Primary muscle or neuromuscular diseases, including mitochondrial diseases and enzyme deficiencies such as aryl sulfatase and acid maltase
This is an extremely common medical illness characterized by fatigue and irritability.
Although emotional lows or sadness may be present, many people with medical depression do not report these feelings. Interrupted sleep, change in sex drive, pain, lack of enjoyment, change in bowel habits, difficulty with concentration, and feelings of worthlessness also characterize depression.
These symptoms often overlap with those of overtraining. Just as most of us don’t appreciate how common depression is in the general population, relatively few realize how many athletes suffer from depression.
Depression is very effectively treated with medication—antidepressants. Antidepressant medications not only can improve and lengthen athletic careers, they can improve overall quality of life.
Chronic Fatigue Syndrome
This is a poorly understood medical condition. No consistent physical findings, laboratory tests, causes or treatments exist.
As is the case with other medical problems that remain poorly defined, personal testimonial and anecdotal reports, often presented with considerable conviction, cloud the scientific evidence.
At one time, Epstein-Barr virus was thought to be related to this problem. Current evidence dismisses this possibility. Some patients’ symptoms may be improved by the simple addition of salt to the diet. It is clear that depression is often present.
Approach to Medical Testing
After a physician’s interview and physical examination, it is reasonable to have some testing. Here’s my approach:
It is unreasonable to perform every possible test. Without any clues, such an approach is too expensive and the occurrence of some problems too low to justify testing. This also means that some relatively uncommon or unusual but definite problems may be missed.
Level 1 Diagnostic
These are tests for problems that occur relatively frequently or are tests that are relatively inexpensive. Many of these tests are often included as part of routine examinations of athletes and non-athletes alike.
- CBC (complete blood count includes hemoglobin, hematocrit, and white blood cell count)
- Blood chemistries, comprehensive (includes testing for glucose [diabetes], electrolytes, liver and kidney function tests)
- TSH (thyroid stimulating hormone, test for thyroid function)
- Sedimentation rate (non-specific test, may help point to rheumatologic diseases)
- HIV test
- STS (syphilis test)
- Urinalysis (inexpensive test of kidney function)
Level 2 Therapeutic Trial Diagnostic
Depression is so common a problem that after a history, physical, and level 1 diagnostic tests, a 6-week trial of antidepressants is often worthwhile.
Since not only depression, but many other medical problems also improve with antidepressants, it’s not surprising that symptoms improve in many riders given a therapeutic trial. Remember fatigue, not sadness, is the most common feature of medical depression.
Level 3 Diagnostic
These tests may uncover problems that are either less common or usually are present with other symptoms or signs uncovered by history and physical examination. If such symptoms or signs are present, these tests are generally performed as part of a level 1 diagnostic.
- Free testosterone (in men over 40)
- Lyme disease test (especially for mountain bikers and those living in endemic areas)
- Stool for ova and parasites, stool culture (especially for riders who travel or who live in states bordering Mexico)
- Exercise treadmill (especially for those over 40)
- Heavy metals screen (with exposure history)
Level 4 Diagnostic
These tests are relatively rarely performed. The problems these tests uncover are either unusual, unlikely to be treated if found, or expensive to test for.
However, if specific symptoms or signs are present on physical examination, or where the stakes are high (for example, professional athletes with large incomes) these tests may be performed.
- Protein and immuno-electrophoresis for immune diseases and plasma cell disorders
- Vascular studies of the lower extremities
- Nerve conduction studies of the lower extremities
- Muscle biopsy
Talk With Your Doctor
By all means show this article to your regular physician if this assists you in checking out the medical possibilities.
Although the blood tests are reasonably standard, some non-sports physicians are not aware of how commonly heart disease in athletes is first discovered based on decreased performance.
Stress (good and bad changes), anxiety, and other psychological problems very commonly cause decreased performance.
Perceptual problems occur are when athletes are riding well but believe that they are not.
Objective testing and records of past performance help evaluate current fitness relative to past performance. An objective opinion about the relative performance of other athletes also helps evaluate this possibility.
Aging-Related Hormonal Decline
All of us will see declines in performance as we mature as athletes. Aging is associated with performance decline for many reasons. In some athletes this decline is associated with low levels of sex hormones—testosterone in men and estrogen in women.
In both men and women, sex hormones can be supplemented and performance may improve. However, short- and long-term side effects may make such supplementation unwise and testosterone supplementation is generally against competition rules.
Medical problems can underlie poor performance. This article was intended to provide a rational framework for a cyclist and physician to investigate medical issues as an explanation for decreased exercise capacity.