Why Athletes Need Their Own Panel

The standard health screening your doctor orders once a year isn't designed for athletic performance. It's designed to catch disease. And the reference ranges it uses? They're based on the general population, which includes a whole lot of sedentary, metabolically unhealthy people.

"Normal" for the general population is not the same as optimal for someone pushing their body hard. An athlete's ferritin level that falls in the "normal" range might still be low enough to impair oxygen delivery and endurance. Testosterone in the low-normal range might be fine for someone with just a desk job but it could explain why recovery has tanked for the athlete balancing both that job with their intense training.

You need a panel that accounts for athletic demands and uses performance-oriented reference ranges, not just disease-avoidance ranges.

Iron and Oxygen Delivery

Iron status might be the single most important blood marker for endurance athletes, and it's one of the most commonly deficient nutrients in athletes overall.

Ferritin: Your Iron Storage Marker

Ferritin is your iron storage marker, and it's far more useful than serum iron alone. For optimal athletic performance, you want ferritin in the range of 50-150 ng/mL. Many athletes, especially female athletes and endurance athletes, run much lower.

Foot-Strike Hemolysis and Female Athletes

Endurance athletes are also prone to iron loss through foot-strike hemolysis, where repetitive ground impact mechanically damages red blood cells and lowers haptoglobin. Long runs and high weekly mileage can accelerate this process. In female athletes, menstrual blood loss and post-exercise hepcidin spikes that temporarily reduce iron absorption further compound the risk.

Low ferritin crushes your VO2 max, increases perceived effort, and slows recovery. It can also cause fatigue that mimics overtraining. You can look like you're doing everything right and still underperform because your iron stores are depleted.

CBC and Red Blood Cell Production

Complete blood count (CBC) with differential gives you hemoglobin and hematocrit, which tell you about your blood's oxygen-carrying capacity. MCV (mean corpuscular volume) helps distinguish between different types of anemia. And reticulocyte count shows how actively your body is producing new red blood cells.

Inflammation and Recovery Markers

Some inflammation is good. It's how your body adapts to training stress. But chronic, excessive inflammation means you're not recovering, and it eventually leads to injury, illness, or plateau.

hs-CRP (high-sensitivity C-reactive protein) is a general inflammation marker. For athletes, you want it below 1.0 mg/L ideally. If it's consistently elevated, something in your training, recovery, nutrition, or lifestyle needs attention.

Creatine kinase (CK) is a marker of muscle damage. It will naturally be elevated after hard training, but persistently high levels can indicate you're not recovering between sessions. ESR (erythrocyte sedimentation rate) is another inflammatory marker that helps complete the picture.

Homocysteine and Methylation

Homocysteine is worth checking because it's associated with inflammation, cardiovascular risk, and poor methylation, all of which matter for athletic performance. Elevated levels (above 10 μmol/L) reduce production of dopamine, norepinephrine, and serotonin—neurotransmitters critical for motivation, focus, and mood during training. It's a marker of B vitamin status (folate, B6, B12). If elevated, supplement with methylated B vitamins (methylfolate, methylcobalamin) and retest in 8-12 weeks.

Hormones and Performance

Your hormonal environment dictates how well you build muscle, burn fat, recover from training, and handle stress.

Male Hormone Panel

For male athletes, testosterone (total and free), SHBG, estradiol, and cortisol are essential. Men over 40 should pay particular attention to testosterone trends.

Female Hormone Panel and RED-S

For female athletes, estradiol, progesterone, testosterone, DHEA-S, and cortisol paint the performance picture. Female athletes also need to be vigilant about RED-S (Relative Energy Deficiency in Sport), where insufficient caloric intake suppresses hormone production. Low estrogen, irregular or absent periods, and declining bone density are red flags. Male athletes develop RED-S just as often, but without menstrual changes as an early warning. Testosterone can drop 50% or more, yet most men don't notice changes in libido or strength until levels are critically low, making blood testing the only reliable way to catch it early.

Cortisol and the Catabolic-Anabolic Balance

Cortisol deserves special attention for all athletes. Training is a stressor, and cortisol is the stress hormone. In the right amounts, it's beneficial. But chronically elevated cortisol from overtraining, under-eating, poor sleep, or life stress will tank your recovery, suppress your immune system, and catabolize muscle tissue. This creates what's called the "open window" or "athlete window" in the hours after heavy training, where immune function drops 15-70%, dramatically increasing infection risk, especially after marathons, ultras, or peak training blocks.

The cortisol-to-testosterone ratio is one of the most useful performance metrics you can track. When cortisol is high relative to testosterone, your body is in a catabolic (breakdown) state. When the ratio favors testosterone, you're in an anabolic (building) state.

Electrolytes and Minerals

Athletes lose significant minerals through sweat, and deficiencies directly impair performance. Magnesium affects muscle contraction, sleep quality, and over 300 enzymatic processes. Most athletes are deficient. Zinc supports testosterone production, immune function, and protein synthesis. Sodium and potassium balance affects hydration and nerve function.

Vitamin D is critical for muscle function, bone health, immune function, and even testosterone production. Athletes who train indoors are especially prone to deficiency.

Calcium is obviously important for bone health, but it also plays a role in muscle contraction and nerve signaling. And selenium supports thyroid function and acts as an antioxidant, which matters for recovery.

B vitamins deserve attention too, particularly B12 and folate. They're involved in energy metabolism, red blood cell production, and nervous system function. Athletes with plant-based diets are at higher risk for B12 deficiency, but even omnivore athletes can run low if they're training intensely and not absorbing nutrients efficiently.

Overtraining Markers: Knowing When to Back Off

One of the hardest things for athletes to do is recognize when they're doing too much. Blood markers can give you objective data that cuts through the "just push harder" mentality.

Immune and Hormonal Warning Signs

A suppressed white blood cell count can indicate immune suppression from overtraining. Chronically elevated cortisol with declining testosterone tells you the same thing. Elevated resting CK levels that don't come down between sessions are a warning sign. And if your ferritin is dropping over time despite adequate iron intake, your body might be burning through stores faster than you can replenish them.

Thyroid Function and Growth Hormone

Thyroid function (TSH, free T3, free T4) is another piece of the overtraining puzzle. Chronic overtraining can suppress thyroid function, leading to fatigue, weight gain, and decreased performance that gets worse the harder you push.

Growth hormone and IGF-1 (insulin-like growth factor 1) also decline in overtraining. Low IGF-1 impairs tissue repair and adaptation, if yours is trending down over training cycles, you're not recovering. Insulin sensitivity can also worsen, making it harder to replenish glycogen even when carb intake is adequate.

Lipoprotein(a): The Genetic Wildcard

Lipoprotein(a) is a genetically determined cardiovascular risk factor that has some impact by diet, exercise, and lifestyle interventions that typically improve other lipid markers. It's over 90% genetically driven.  Some evidence suggests intense endurance training may paradoxically increase Lp(a) by 10-15%, even as other cardiovascular markers improve. This matters because studies show that aging endurance athletes with elevated Lp(a) have increased coronary artery calcification and plaque buildup despite having low conventional risk factors and training consistently for decades. Because Lp(a) is stable throughout life, test it at least once to establish your baseline risk, if elevated (above 50 mg/dL or 125 nmol/L), it may be recommended to get additional cardiovascular screening like coronary calcium scoring or echocardiogram. From there, focus on aggressively managing modifiable factors—LDL, APOB cholesterol, blood pressure, inflammation, to offset the cardiovascular risk that high Lp(a) creates, even in athletes who do everything else right.

Building Your Athletic Testing Protocol

Test at least twice per year, ideally at the start and midpoint of your training season. If you're in heavy training, every 3-4 months is better. Test in a consistent state: same time of day, same distance from your last hard workout, fasted.

Geviti's comprehensive panel covers all the markers discussed here and more, with over 100 biomarkers in a single at-home blood draw. The AI-powered trend tracking is particularly useful for athletes because it shows how your markers change over training cycles, helping you optimize timing for peak performance.

What to Do With Your Results

Getting tested is step one. Understanding what to do with the results is where the real value lies. Don't just glance at whether your markers are flagged as high or low. Look at where you fall within the range and how your numbers compare to previous tests.

For example, ferritin at 35 ng/mL is technically "normal" but might explain why your endurance has plateaued. A cortisol-to-testosterone ratio that has shifted significantly from your last test could signal the onset of overtraining before you feel it. Context and trends matter more than any single data point.

Work with a provider who understands athletic physiology, not just disease detection. The difference between standard medical ranges and performance-optimized ranges can be the difference between feeling "fine" and actually performing at your best.

Your training log tells you what you did. Your bloodwork tells you how your body responded. You need both. Proactive health testing in your 30s sets the foundation for long-term athletic performance. High-performing professionals benefit from similar optimization strategies.

References

PMC (2024). "Age-related testosterone decline: mechanisms and intervention strategies." pmc.ncbi.nlm.nih.gov. Testosterone decline rates and mechanisms.

Leproult, R. & Van Cauter, E. (2011). "Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men." JAMA, 305(21), 2173-2174.

Forrest, K.Y. & Stuhldreher, W.L. (2011). "Prevalence and correlates of vitamin D deficiency in US adults." Nutrition Research. 41.6% deficiency rate per NHANES data.

PMC (2022). "Markers of insulin resistance in Polycystic ovary syndrome women: An update." Discusses ferritin, iron, and nutrient biomarker thresholds.

Sleep Medicine Reviews (2021). "Effect of partial and total sleep deprivation on serum testosterone in healthy males: a systematic review and meta-analysis." 18 studies, 252 men analyzed.

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