Enduring Fatigue

training tips

By Stephen Keiser, MD;  Sports & Exercise Medicine Center, Bon Secours Medical Group

Fatigue can be a normal and important response to physical exertion, emotional stress, boredom or lack of sleep. However, it can also be a nonspecific sign of a more serious issue.

During my first year as the team physician for a Division I University, I was asked to evaluate almost half of the cross country team for fatigue. The team had recently adopted the training schedule of their All-American, who was running 85-90 miles a week. They were having good results, but not all of the runners adapted well to the extra mileage. By decreasing their mileage, we saw an increase in performance and energy in the rest of the team.

We need to experience fatigue - if only briefly - to determine what duration and intensity our bodies are capable of handling. Most endurance athletes will experience longer periods of fatigue. When this happens, it can be corrected by addressing some of the most common causes.

Overtraining

As a sports medicine physician, I spend a lot of time encouraging people to get off the couch, but you can get too much of a good thing. Exercise is good medicine, but overtraining is a very common cause of fatigue, and often involves many of the components listed below.

Lack of Rest

The vast majority of athletes recover best with seven to ten hours of quality sleep each night. More sleep, including naps, might be necessary. Additionally, other physical activities such as yard work need to be factored into an athlete's schedule to allow for adequate recovery during the day and night.

Insufficient Nutrition

Many people try to lose weight while training, which can cause a significant calorie deficit which adversely affects their energy level. The stress of ten or more hours of exertion a week can also deplete some key nutrients and cause fatigue. A good assessment of your energy balance - preferably with a dietitian - can determine if poor nutrition is an issue for you.

Hormone Imbalance

Low thyroid hormone level is the most prevalent hormone imbalance that causes fatigue in athletes. Simple blood tests can identify this, and usually it is fairly easy to correct with proper medication.

Iron Deficiency

Iron deficiency - with or without anemia - is common in female endurance athletes. Many universities now screen their female athletes with blood tests, and some schools have found up to 30% of their women have low iron stores. Men can also have low iron levels. Low iron is corrected by diet modification and medicine if needed. I don't advise taking significant iron supplements without knowing your blood levels, as too much iron can cause other issues.

Asthma

A recent review of exercise induced asthma (EIA) suggested a prevalence in elite athletes of 10-50% - depending on the sport. EIA is often associated with coughing, wheezing, etc., but in some cases it simply causes fatigue with no other obvious symptoms. If needed, pulmonary function tests can help diagnose this, as well as help determine appropriate treatment.

Heart Conditions

Any time an athlete continues to have fatigue despite addressing the above issues, the health of their heart and cardiovascular system should also be assessed by a physician and, if needed, tested.

As seen in the September 2010 issue of Go Magazine.