10 Biomarkers That Matter Most for Your Health — and How WHOOP Advanced Labs Brings Them to Life

When it comes to your health, the details matter. Tiny changes at the cellular or molecular level can shape things like how much energy you have, how you recover, and even how long you live. These signals are called biomarkers, which are measurable indicators of how your body’s systems are functioning.

Every biomarker that WHOOP Advanced Labs tests contributes to your health. Some reflect how your body responds day-to-day, others track long-term health, and together they give you a comprehensive view of your wellbeing. Below are ten biomarkers that are easy to connect to daily routines like sleep, training, and recovery — and ways that WHOOP Advanced Labs makes results actionable in your life.

1. HOMA-IR Score: Your Body’s Fuel Efficiency

A gold-standard measure of how well your body responds to insulin — the hormone that helps move sugar from your blood into your cells for energy. Higher scores can indicate reduced metabolic efficiency, which can raise long-term risk for type 2 diabetes, cardiovascular disease, and difficulty losing weight. WHOOP Advanced Labs pairs this result with recovery and strain data like VO₂ Max and lean body mass to give context on how your body handles energy and stress.

2. Apolipoprotein B (ApoB): Traffic on Your Arteries’ Highway

ApoB is the biomarker of long-term cardiovascular risk preferred by preventive cardiologists and longevity experts. Instead of just measuring cholesterol levels, it counts the number of cholesterol-carrying particles in your blood — like trucks on a highway that can cause congestion. With WHOOP Advanced Labs, you can view ApoB results alongside your cardiovascular and recovery metrics like resting heart rate for a clearer picture of heart health.

3. High-Sensitivity C-Reactive Protein (hsCRP): Your Body’s Smoke Alarm

hsCRP is a marker of systemic inflammation and heart health. Because it can fluctuate day to day, it acts as a powerful early signal of how your body is responding to stressors. Chronic elevation is linked to fatigue, slower recovery, and long-term disease risk. WHOOP Advanced Labs helps contextualize hsCRP trends with your strain and sleep patterns so you can see how lifestyle choices may influence inflammation.

4. Cortisol: Your Stress Alarm Clock

Most commonly known as the stress hormone, cortisol affects recovery, sleep, focus, and energy regulation. Dysregulated cortisol can disrupt performance and slow recovery. WHOOP layers cortisol results with HRV and strain data to provide insight into how your stress may connect to your physiology.

5. Free Testosterone: Your Body’s Building Permit

Free testosterone is essential for strength, muscle growth, recovery, and sexual health. In both men and women, it plays a major role in libido and desire, making it a key marker of overall vitality. Low levels can contribute to fatigue, poor recovery, or plateaued training — and may explain difficulties in the weight room or the bedroom. WHOOP Advanced Labs helps you see free testosterone in the context of performance and recovery outcomes, including lean body mass, strength training, HRV, and more.

6. Estradiol: Your Internal Thermostat

Estradiol is a key sex hormone for both women and men, influencing sexual health, fertility, mood, energy, and metabolism. Imbalances can contribute to symptoms like irregular periods, low libido, or changes in recovery and training response — issues that may go unnoticed or feel hard to talk about. WHOOP Advanced Labs adds context by layering estradiol values into your broader health data, including patterns in sleep and weight, to help surface where imbalances may be affecting performance or well-being.

7. Thyroid-Stimulating Hormone (TSH): The Master Switch for Energy

TSH regulates thyroid function, which drives metabolism, energy, and mood. Impaired thyroid function, detected through elevated TSH, is one of the most common medical causes of issues like fatigue, sluggish performance, and weight gain. WHOOP Advanced Labs helps surface how thyroid function may connect to your recovery and readiness patterns.

8. Hemoglobin: Your Oxygen Delivery Service

Hemoglobin is essential for transporting oxygen from your lungs to your muscles and brain, supporting endurance and overall performance. Low levels can cause fatigue, shortness of breath, or poor exercise capacity. With WHOOP Advanced Labs, you can see hemoglobin results alongside strain and recovery data to better understand when low oxygen capacity might be affecting your energy.

9. BUN/Creatinine Ratio: Your Hydration and Filter Check

This kidney function marker gives insight into hydration status, protein metabolism, and overall renal health. Elevated ratios can indicate a need to replace fluids from training or inadequate hydration. WHOOP Advanced Labs helps you see this result in the context of strain and VO₂ Max, offering a clearer view of how your body manages fluid and protein balance under stress.

10. Ferritin: Your Iron Savings Account

This protein stores iron, essential for oxygen transport. Low ferritin is linked to fatigue, poor aerobic capacity and reduced cognitive sharpness, whereas excessively high ferritin can be seen in states of iron overload or bodily inflammation. WHOOP Advanced Labs shows your ferritin levels alongside VO₂ Max and heart rate zone data, giving you clearer context for how nutrient status may impact endurance and performance.

How Much Can You Really Change?

Most biomarkers don’t shift overnight. Depending on the biomarker, you could see meaningful progress in about 3–6 months, though the exact timeframe depends on the marker and your circumstance. For example, inflammation markers like hsCRP can change within days, while cholesterol and metabolic markers typically take several months to reflect new habits. Nutrient-related biomarkers, such as ferritin or vitamin D, may also take time to replenish if levels start low.

It’s also worth remembering that some biomarkers may require attention, despite being influenced by factors you can’t fully control. Lipoprotein(a), for instance, is mostly genetic, while others like certain blood cell counts don’t change much outside of illness. Even for highly coachable markers like HOMA-IR or ApoB, genetics and environment play a role in how much improvement is possible.

The goal isn’t just to hit a single “optimal” number, but to see patterns over time, understand how habits influence your results, and get context for the areas where you can make an impact.

Take the Next Step

Your health is more than numbers in lab results – it’s an ongoing story that changes regularly through your habits, stress, sleep, training, and more. With WHOOP Advanced Labs, you finally have the tools to understand that story and act on it.

Ready to understand your biomarkers? Join the waitlist for WHOOP Advanced Labs today.

Important information

WHOOP Advanced Labs does not provide medical advice or diagnoses, and the services and content in WHOOP Advanced Labs are not intended, designed, or implied to diagnose, prevent, monitor, treat, or alleviate any illness or medical condition or disease, to ascertain the state of users’ health, or to be a substitute for professional medical care. The information available through WHOOP Advanced Labs is provided solely for the purpose of improving wellness through education. You should consult your primary care provider or other healthcare providers if you have any questions about any implications of information or results in WHOOP Advanced Labs and before making any changes to your diet or exercise routine. Bloodwork testing offered through WHOOP Advanced Labs is not comprehensive and may omit tests that are relevant to you. WHOOP cannot verify the accuracy of third-party content. WHOOP uses artificial intelligence to generate information in WHOOP Advanced Labs. Artificial intelligence can make errors, and you are responsible for confirming the information provided by WHOOP Advanced Labs. WHOOP does not recommend any particular supplements or dietary changes. Regional restrictions may apply.