Are these blood results normal for athletes?
Athlete Blood Test specializes in making sure you are optimizing your individual physiology. That means we come across many interesting and unique findings- findings as unique as YOU! Normal blood results for athletes can be difficult to establish. Below you’ll find what we think of as “weird science” in the blood biomarker world: some uncommon issues, lesser-known facts, and a few unusual solutions to issues we’ve identified in athlete blood biomarkers.
White Blood Cell Count (“WBC”)
White blood cell count measures immune function or the total amount of white blood cells circulating in the blood. Low WBC can suggest overtraining or under-recovery, infection, or excessive inflammation. Slightly low WBC can be an adaptive response to endurance training with little to no impact on training or immune function.
High WBC is commonly associated with infection and should be discussed with a medical professional. It can also be a sign of high inflammation. If an athlete has high WBC that we suspect (based on their questionnaire) is correlated to high inflammation (after other medical issues have been ruled out), we often recommend that the athlete consider dietary changes (more antioxidant-rich foods), adding an additional recovery day, or other recovery strategies such as massage.
High Neutrophils
Neutrophils are a type of white blood cell. If they are high, it could be from an unknown infection. But strenuous exercise also can cause a temporary increase, with peak levels about 5 hours after exercise. If due to an unknown infection, depending on the type and severity, it may reduce an athlete’s ability to train or compete in the short term. If we suspect an infection, we will recommend that the athlete check in with their physician.
Iron Issues
Iron issues aren’t uncommon, but sometimes the reasons are. Check out a few of our latest articles on iron and ferritin here and here if these are issues for you. And an uncommon tip: athletes are less able to absorb non-heme (plant-based) iron 3-6 hours after a workout, so we often recommend folks with low iron consume iron right after a workout or at least 6 hours later to optimize iron absorption.
Low Vitamin D & Testosterone.
We sometimes see low vitamin D and low testosterone together. This isn’t surprising– low vitamin D can be a cause or contribute to low testosterone. Low testosterone is associated with decreased power, performance, and a sense of well-being in athletes. Check our article on Low Testosterone. If athletes have low testosterone, we will often recommend that they increase vitamin D (if suboptimal), increase fat intake, rest, and recovery (and reduce training load at least temporarily), get quality sleep, and eat enough calories to cover their energy demands and fuel recovery.
Fun fact: testosterone levels peak in the morning for men. In some men, testosterone can drop as much as 40% from peak levels throughout the day!
Low Platelet Count
Platelet count can drop at the beginning of an athlete’s training season as their body adjusts to the new demands. Platelet count can recover if an athlete gradually increases training load and calorie intake (i.e., eats more) as training increases.
High Blood Calcium
High blood calcium can actually be a sign that an athlete isn’t consuming enough calcium. Not eating enough calcium is a problem, because it can weaken your bones, cause kidney stones, and interfere with your heart and even brain function. High blood calcium can occur when an athlete isn’t eating enough. An athlete’s body is smart and tightly regulates blood calcium- if you aren’t eating enough, it will take it from your bones. To avoid this, we often recommend athletes consume at least 1,000 mg of calcium per day.
Taking too many calcium supplements can also cause high calcium. Really high calcium is typically a sign there is something going on with your parathyroid gland and should be further explored with your medical professional.
Elevated ALT and AST
ALT and AST are liver enzymes. But they are actually found in muscle too. Elevated ALT and AST sometimes occur because an athlete has done a workout before a blood draw. If that is the case, there isn’t much to do- except avoid working out before your blood draw next time so we can get a better picture of true ALT and AST levels. But if an athlete gets a blood draw on a recovery day and still has elevated ALT and AST later in their season-particularly if they report fatigue or slow recovery-it could mean that they need to reduce training intensity to allow muscles to recover. Keep in mind that ALT and AST can be elevated for up to 10 days after competition or a really intense workout.
Low Alkaline Phosphatase
Alkaline phosphatase is an enzyme found in the liver, bones, kidneys, and digestive system. Low levels of alkaline phosphatase can be from a zinc deficiency or malnutrition, suggesting that an athlete’s nutrition strategy isn’t working for them. We often recommend that athletes with low alkaline phosphatase work with a sports RD to make sure they are getting the right amount of energy based on their training demands.
High Albumin
Albumin is the most abundant protein in the blood; it helps with transportation and blood fluid levels. High albumin isn’t unusual in athletes, but sometimes the “why” can be tricky. It can indicate dehydration, so we cross-reference other blood biomarkers to see if an athlete is likely to be dehydrated. If other blood biomarkers don’t suggest dehydration, high albumin levels are likely a response to exercise and not a big deal. If other blood biomarkers suggest dehydration, we recommend the athlete take a look at their hydration plan.
SHBG and Low Free Testosterone.
Sex hormone-binding globulin (SHBG) is a protein that binds to testosterone and renders it inactive. When SHBG binds to free testosterone, it blocks testosterone from being able to bind to receptors and do its job or have an effect (it is like a key that doesn’t fit into a lock). Low free testosterone is associated with reduced training capacity, performance, and sense of well-being. One potential cause of SHBG causing low free testosterone is birth control containing estrogen. We often recommend that athletes with this issue consider discussing their contraceptive options with their medical providers.
Normal blood results for athletes
