Blood Chemistry FAQ


Red Blood CellsBy Dan McCarthy//High Performance Consultant

One of the most popular offerings enjoyed by the USA Swimming National Team is the Blood Chemistry Program. We have detailed the draws that are a part of this program in this space before. The response to sharing this information with the USA Swimming community has been awesome and inspired some excellent questions.

What is the most important test? 

Obviously, the whole program is important and many of the tests offer clues to why another result might be high or low, but the Iron Profile/Ferritin tests have revealed serious issues (health and training) for many National Team athletes. Low Ferritin stores can lead to low red blood cell production, which will compromise an athlete’s ability to train. We have had Olympic medalists, National Junior Team athletes and Olympic Trials finalists test low for Ferritin, and suffer from the initial stages of anemia. Regardless of level of accomplishment, gender or age, the Iron Profile/Ferritin test has most often helped answer the question, “What’s wrong?”

What is the most common deficiency? 

Vitamin D comes back below optimal for more of our National Team athletes than any other test we perform. Unfortunately, this deficiency is largely because much of our country’s population lies so far north of the equator. The best source of Vitamin D is the sun, but swimmers spend a large portion of time training and competing indoors. Even just fifteen minutes of exposure a day can make a difference. Studies are popping up more frequently touting the benefits of maintaining optimal levels of Vitamin D for the general population and athletes as well.

How often should blood draws be scheduled? 

The specific dates of the test are going to vary, team to team and athlete to athlete. However, some general recommendations apply to everyone.

  • An out-of-season or baseline test is an ideal opportunity to establish some values either at the high or low end of an athlete’s specific range.
  • A test before and after the highest intensity block of work during the long course and short course season usually yields great information regarding an athlete’s training response.
  • A test before and after attending an extended altitude camp (25 or more days) will provide insight on an athlete’s response to altitude training.

The coaches and athletes who have planned blood draws based on their training schedules have collected very useful information for designing future training plans, identifying successful training strategies and avoiding chronic health issues.