Reading your blood

We live in an age of amazing technology. So amazing it is, in fact, that it takes much of the guesswork and mystery out of our daily lives, for an ever decreasing cost. Things that we may have never known about ourselves, like the regular status of our blood, can and should become a regular diagnostic routine.

By Rick Crawford

Red blood cells: They may be small, but they carry a lot of information

Red blood cells: They may be small, but they carry a lot of information


We live in an age of amazing technology. So amazing it is, in fact, that it takes much of the guesswork and mystery out of our daily lives, for an ever decreasing cost. Things that we may have never known about ourselves, like the regular status of our blood, can and should become a regular diagnostic routine.

For athletes in general ? and endurance athletes in particular ? the status of the blood is of paramount importance. Blood is our delivery system for oxygen, fuel substrates, and a myriad of substances, carefully controlled by the synergistic conglomerate that constitutes our body. Blood carries the actual freight, while our central nervous system communicates as by wire. Blood that is healthy will deliver more oxygen to an athlete’s muscles. Blood is where great immunological battles are fought for us every day, with many of its components dedicated to fighting off unwanted invaders that challenge our health. Blood is essential to life, and essential to good performance.

Endurance athletes purposefully train to increase their bodies’ strength. Good performance is a dividend of the optimization of many factors, blood being a very important factor. Blood status is often taken for granted, as it is an invisible entity that doesn’t get sore as it is worked harder and harder. It does however, get depleted and tired, quietly resulting in general degeneration of form and vigor of the athlete.

It doesn’t have to be this way. These days there are relatively inexpensive diagnostic tools that, if done on a regular basis, can bring the invisible microscopic elements of the blood into clear view. These diagnostics, done as regular routine, provide a baseline of health that can be quantified and managed to consistent and great results in the athletic arena.

At a minimum, an endurance athlete should have a blood test done on a quarterly basis. Quarterly bloodwork will show baselines and common variations due to training, periodic stress and immune challenges. Quarterly bloodwork may be supplemented by tests done to diagnose illness or to more closely monitor health and form. Frequent bloodwork can serve as a preventative measure for many common maladies of endurance athletes, such as overtraining, fatigue, anemia and illness.

For those of us who don’t have the benefit of a team doctor, we have to rely on a health professional (an MD, a physician’s assistant or nurse practitioner) to prescribe and analyze the bloodwork. It is important to foster a good relationship with a doctor who understands that these diagnostics are vital to the health and prosperity of a serious endurance athlete. Many doctors are reluctant to order bloodwork for an apparently healthy patient, but for an endurance athlete, regular blood tests are important proactive measures to ensure optimal health and performance. Furthermore, a medical professional, normally focused on treating the unhealthy, may not know how to interpret results from a performance perspective. A good doctor to help manage health and vigor should be a key component of an endurance athlete’s infrastructure.

The reason managing blood is so important is that ambitious athletes are always pushing hard to get gains, and in this process, often push until a key system catastrophically fails. In many cases, it is the blood or an element thereof that is pushed beyond its limits.

Iron is a good example. It is often depleted and becomes a limiter for health and performance. Iron is the component that binds oxygen in hemoglobin, and as such, when there is not enough of it, red blood cell production is limited, which in turn limits oxygen carrying capacity. Red blood cells are constantly being destroyed and created, and in the case of hard-charging endurance athletes, the tendency to self-destruct is common. Iron is constantly excreted, albeit slowly. Iron is also very slowly absorbed from the diet, so even heavily supplementing iron is no guarantee to better absorption. Iron must be absorbed into the bloodstream and incorporated so as to be of use eventually as a heme molecule. Serum iron levels are not necessarily indicative to good iron status, as it is iron that has been absorbed, but not yet incorporated into a bioactive form. Ferritin, on the other hand, is the form of iron ready to go to work in the formation of heme molecules, and on to the task of carrying oxygen. Iron in the blood, but not yet incorporated into a useful form, can actually prove to be toxic to the body. It is very important that iron be regulated and monitored by endurance athletes to ensure good health and good performance. Managing iron through bloodwork and proper nutrition should be an important priority for serious endurance athletes.

When an athlete gets a blood draw, the usual protocol should be for the doctor to order a CBC (complete blood chemistry), and ferritin test. This is the basic testing protocol for a quarterly test. There are many more things to measure in blood, but unless the doctor thinks it necessary to probe further, CBC and ferritin test will provide adequate information for determining baselines.

The CBC will show a number of key values and their reference ranges, which indicate the normal range of these values. Hct (hematocrit) and Hgb (hemoglobin) are two critical factors of the CBC test which generally indicate the oxygen carrying capacity and concentration of the blood. These two values should be very familiar to any endurance athlete and baselines should be set and managed very carefully through monitoring, nutrition, and periodized training.

WBC (white blood cells), if elevated, may indicate a bacterial infection. Elevated lymphocyte levels indicate viral activity. Ferritin indicates ready iron stores. High eosinophils levels indicate some form of allergic reaction. There are many more values and relationships that an athlete, along with the qualified diagnosis of a good doctor, can evaluate and manage.

Tests that measure cortisol and free testosterone are an effective method of tracking the effects of stress. Cortisol accumulates when an athlete is under stress without adequate recovery. Testosterone generally declines when athletes are overtrained, and will be marked by a lack of vigor, motivation, and performance. These tests are not part of a CBC and will cost a bit extra, and might be reserved for times when symptoms of overtraining need to be confirmed.

There will always be an ongoing relationship between ferritin and hematocrit/hemoglobin, whereas red blood cells die, releasing their iron stores as ferritin into the bloodstream, so that decreased hematocrit may actually yield higher ferritin counts. Ferritin levels will trend downwards throughout the season as iron excretion outruns absorption. Manipulating hematocrit and ferritin would then be a matter of recovery, nutrition, and good planning. The point is that these values should be managed by the athlete and shouldn’t be randomized or taken for granted.

Blood should not be taken for granted. It should be monitiored, analyzed and understood. It is such an important aspect of health and fitness and should not be neglected. A proactive stance on blood status is critical for the achievement of endurance athlete potential. Test often, get baselines, keep records and then act on the information. Potential isn’t achieved by accident.

Rick Crawford is Director of Coaching and COO of Colorado Premier Training. He is also the head coach for the Fort Lewis College cycling team in Durango, Colorado.