Biomarkers for Performance: What Your Training Leaves Behind

Training is a controlled stress applied to a living system. The goal is adaptation, not exhaustion. This adaptive process, known as hormesis, depends on adequate recovery resources. When training stress exceeds the body’s ability to repair and refuel, the physiology begins to compensate. Performance may hold steady for a time, but internal strain accumulates.

These shifts are not always visible in training data. They are visible in biology. At Aware, we use biomarker testing to identify whether your internal environment is supporting adaptation or quietly drifting toward depletion.

1. Hormonal Bioavailability and Recovery Signaling

Recovery is regulated by the endocrine system. Rather than focusing on isolated hormone values, we assess whether the hormonal environment supports tissue repair and metabolic stability.

Total testosterone alone provides limited insight. Free testosterone represents the fraction that is biologically active and available to tissues. Sex Hormone Binding Globulin (SHBG) plays a central role in regulating this availability. In athletes, higher training volume, energy deficiency, and cumulative stress are commonly associated with elevated SHBG, which can reduce free testosterone even when total levels appear normal.

We also evaluate DHEAS, a precursor hormone produced by the adrenal glands. DHEAS reflects longer-term endocrine resilience rather than acute stress. Declining trends may indicate that recovery capacity is being challenged by training load, insufficient energy intake, or inadequate rest.

• What to check: Free testosterone, SHBG, DHEAS
• Aware package: Male Hormones or Female Hormones
• Action plan: Low free testosterone in the presence of elevated SHBG often reflects constrained energy availability rather than primary hormonal dysfunction. Increasing total caloric intake—particularly from carbohydrates and dietary fats—and adjusting training load can help restore a recovery-supportive hormonal environment.

2. Oxygen Transport and Red Blood Cell Quality

Aerobic performance depends on efficient oxygen delivery. Red blood cell quantity and quality both matter.

Ferritin reflects iron storage and is a critical marker in active individuals. While clinical reference ranges are designed to detect disease, athletes may experience performance limitations at ferritin levels that are technically “normal.” Low iron availability can impair mitochondrial enzyme function and increase fatigue before anemia develops.

Red blood cell production also depends on adequate vitamin B12 and folate. When these nutrients are insufficient, erythropoiesis (the production of red blood cells) may produce larger and less efficient cells, reducing oxygen delivery to working muscle.

• What to check: Ferritin, Transferrin saturation, Vitamin B12, Folate
• Aware package: Nutrition or Vegetarian Health
• Action plan: Ferritin should be monitored over time rather than interpreted as a single value. Downward trends or persistently low-normal values warrant a review of iron intake, absorption, and overall nutritional adequacy.

3. Inflammation Resolution and Cellular Resilience

Training adaptation requires inflammation that resolves efficiently. When resolution is delayed, recovery slows and tissue quality declines.

The Omega-3 Index measures the incorporation of EPA and DHA into red blood cell membranes. Higher values are associated with improved membrane fluidity and more regulated inflammatory signaling. Lower values may increase susceptibility to oxidative stress during high-intensity training.

We interpret the Omega-3 Index alongside markers such as LDH, which reflects muscle turnover, and hs-CRP, which reflects systemic inflammation. Together, these markers help assess how effectively the body transitions from training stress to repair.

• What to check: Omega-3 Index, LDH, hs-CRP
• Aware package: Omega-3 Index or Long-Term Health
• Action plan: Omega-3 Index values above approximately 8% are commonly associated with favorable recovery profiles, though optimal targets vary by individual. When levels are low, increasing dietary EPA and DHA can support cellular resilience and recovery efficiency.

4. Metabolic Clearance and Renal Load

Intense training produces metabolic byproducts that must be cleared efficiently. When clearance lags behind production, fatigue and systemic strain increase.

Creatinine is frequently used to assess kidney function, but in athletic populations, it can be misleading. Muscle mass and recent exercise both elevate creatinine independently of renal health.

Cystatin C provides a more stable assessment of filtration because it is not influenced by muscle mass or training status. Evaluating Cystatin C alongside estimated glomerular filtration rate (eGFR) allows for a more accurate interpretation of renal workload in athletes.

• What to check: Cystatin C, Creatinine, eGFR
• Aware package: Sport or ESN Elite Athlete
• Action plan: Elevated Cystatin C may indicate increased renal strain or insufficient recovery support. Optimizing hydration, electrolyte balance, and training load distribution can help restore efficient metabolic clearance.

Conclusion

Performance optimization is a transition from guessing to engineering. While external metrics like pace and power quantify your output, internal biomarkers reveal the physiological cost of that work.

At Aware, our goal is to help you close the gap between how you perform and how you recover. By utilizing our specialized packages—from sport to hormones—you move away from subjective assessments of fatigue and toward objective data. This internal feedback loop ensures that your training remains a productive stress that builds resilience, rather than a depleting force that compromises your biological health. With Aware, you aren't just training harder; you are training with the precision needed to sustain peak performance.

‍