What do biomarker trends mean, and why do they matter more than one blood test?

Jim Davis has spent decades in lab diagnostics helping scale one of the biggest testing networks in the U.S., so when he talks about trends in blood work, it comes from a rare vantage point: seeing how biomarkers change over time at population scale. In his WHOOP Podcast conversation with Will Ahmed, he explains why health data works better as a movie than a snapshot, how wearable trends can influence lab outcomes like A1C and CRP, and which tests matter most if you want to get more proactive about long-term health.

A single lab result tells you where you are today. A trend tells you where you are heading. Davis's core point is simple: one number is a still frame, and most health stories only show up when you watch the entire film.

"What's really important in lab testing is never just one point in time." (Jim Davis)

He describes this as velocity: the rate of change in a biomarker over months or years. That matters because many health problems develop gradually. Your A1C might still sit inside the reference range, for example, but if it keeps climbing test after test, the direction itself is the early warning. The same logic applies to lipids, kidney markers, and inflammation.

This is also where trends are more useful than reference ranges. A range is a screening tool. It tells you whether you fall inside a population window, but it does not tell you whether your personal health is improving, drifting, or stalling.

Practical takeaway

• Keep past lab results in one place so you can compare over time.
• Read for direction, then flag the outliers.
• If you are making changes to sleep, training, stress, or nutrition, trends help you see whether those changes are actually working.

Listen to the full episode for Davis on velocity and why one number is rarely enough.

How do wearable trends connect to biomarker trends?

Davis frames it like an equation: Y is a function of X. Your biomarkers are the outcomes (the Y variables, things like A1C, ApoB, LDL, and CRP). Your behaviors and wearable data are the inputs (the X variables, things like sleep, HRV, stress, activity, and nutrition).

That is the bridge between wearables and blood work. Your lab panel shows the result, and your daily physiology helps explain why.

What this looks like in real life

• Poor sleep trends can make it harder to train well, recover well, and make consistent nutrition choices. Over time, that can show up in glucose regulation and A1C.
• High stress trends can drive chronic low-grade inflammation, where CRP (C-reactive protein, a marker linked to inflammation) becomes useful context.
• Better fitness and recovery trends can support healthier lipid and metabolic patterns over time, especially when paired with good nutrition.

This is where existing trend views on WHOOP become more valuable. If you can already see how your sleep consistency, strain, resting heart rate, or HRV are moving, the next step is connecting those daily-physiology trends to your biomarkers.

Practical takeaway

Pick one lab outcome you care about most (say A1C or ApoB), then track two or three wearable inputs that likely influence it. That keeps the feedback loop clear and actionable.

Listen to the full episode for the Y = f(X) framing and how to map wearable data to lab outcomes.

Which biomarkers are most useful to trend for long-term health?

If your goal is longevity-focused screening, Davis keeps the priority list grounded. Start with markers that help you understand cardiometabolic health, inflammation, and foundational body function.

Trend these regularly

• A1C: a 2 to 3 month marker of average blood glucose, useful for spotting early glucose dysregulation.
• ApoB: apolipoprotein B, a measure of the number of cholesterol-carrying particles linked to cardiovascular risk. Often more informative than LDL alone.
• LDL and HDL: still useful, especially when read alongside ApoB.
• CRP: a practical marker of inflammation, especially when lifestyle basics are off.
• Complete metabolic panel (CMP): assesses liver, kidney, and metabolic function.
• Complete blood count (CBC): gives insight into blood cells and immune system status.

Check this once, then use it as context

"Lp(a) is largely genetic, 'one and done.' You just need to check it once in your lifetime." (Jim Davis)

Lp(a), or lipoprotein(a), is a genetically influenced cardiovascular risk marker that is not always included in standard care. It is valuable, but it usually does not need the same repeat cadence as A1C or ApoB. One careful baseline measurement is usually enough.

That nuance matters. Trends are powerful, and the smart move is knowing what to trend, how often, and why.

Practical takeaway

• If you have only ever looked at standard cholesterol, ask whether ApoB and Lp(a) would add clarity.
• Use repeat testing for changeable markers like A1C, ApoB, and CRP.
• Use one-time markers like Lp(a) to refine your baseline risk picture.

Listen to the full episode for Davis on which markers to repeat and which to check once.

How often should you repeat blood work if you are trying to improve your health?

The right cadence depends on your goal. If you are doing basic maintenance and feeling well, annual testing may be enough for some markers. If you are actively trying to improve sleep, body composition, glucose control, or cardiovascular risk, a full year between tests can be too slow.

"There's certain things you're fine to check once a year, but if you're trying to improve your health, some markers are worth checking once a quarter or every six months so you can see the trend." (Jim Davis)

Lifestyle changes take time, but rarely a full year. Quarterly or semiannual testing gives you enough distance to see meaningful movement without guessing in the dark.

A simple cadence

• Once a year: general maintenance when things are stable.
• Every 6 months: useful if you are building better habits and want a clearer trendline.
• Every quarter: best when you are making targeted changes and want faster feedback.

The key is consistency. Similar timing, similar conditions, and repeated testing make trend interpretation much cleaner.

Practical takeaway

Match testing frequency to how aggressively you are trying to change the outcome. The more active the intervention, the more valuable the trend.

Listen to the full episode for Davis on test cadence and why consistency matters.

How do trends help you take action instead of just collecting more data?

The best use of trends is behavior change. Davis calls it "action from insights." That is the whole point. More data only helps if it changes what you do next.

One example from the episode: supplements. Test first, then supplement. If a baseline shows low vitamin D, low B12, or another deficiency, you can respond more precisely. Then re-test to see whether the intervention worked, and whether you overshot. That matters because some nutrients shift with seasonality, sun exposure, diet, and training load.

The same principle applies beyond supplements. If poor sleep and high stress keep showing up alongside rising CRP or worsening A1C, the next move is to tighten the basics: sleep consistency, recovery, training balance, and nutrition quality.

Practical takeaway

• Test before you supplement.
• Use trends to validate whether a change worked.
• Focus on the basics first when inflammation or glucose trends move in the wrong direction.

That is where wearable and lab trends become useful together: one shows your daily inputs, the other shows your downstream outcomes.

Listen to the full episode for Davis on action from insights and how to close the loop.

The bottom line on trends

Health data gets more powerful when you read it as a trendline. Direction shows trajectory. Velocity shows risk. Repeated feedback helps you make better decisions before a problem becomes a diagnosis.

If existing WHOOP trend views have already helped you make sense of your sleep, strain, and recovery, biomarker trends are the logical next step. They help connect what you do every day to what is happening under the surface.

Listen to the full episode with Jim Davis and Will Ahmed for the complete biomarker-trends framework.

Frequently asked questions

What is a biomarker trend?

• A biomarker trend is the direction and rate of change of a blood-work metric over time, rather than a single result on a single date. Trends matter because many health problems develop gradually and a value can sit inside a normal reference range while still moving in the wrong direction. Tracking the same biomarkers (such as A1C, ApoB, CRP) at consistent intervals lets you see whether your physiology is improving, drifting, or stalling.

How can wearables work with blood test results?

• Wearable data and blood work answer different questions. Blood work measures outcomes (Y variables) like A1C, ApoB, LDL, HDL, and CRP. Wearable data measures inputs (X variables) like sleep duration and consistency, HRV, resting heart rate, and training load. The most useful workflow pairs them: pick one lab outcome you care about, then track two or three wearable inputs that plausibly influence it. WHOOP Advanced Labs is purpose-built for this pairing, surfacing biomarker results alongside daily WHOOP data so the relationship is easier to see.

What is the benefit of combining wearable data with blood tests?

• Blood tests show the result, daily wearable data shows the why. A single low Recovery score and a single elevated CRP each tell you something. Together they can point at root causes (stress, sleep loss, training overload, illness) and at which lifestyle levers might move both. Repeated together over months, they show whether interventions are actually working.

How often should I get my blood work done?

• Annually for general maintenance, every six months if you are actively building better habits, and every quarter if you are running a targeted intervention and want fast feedback. The right cadence is the one that matches how aggressively you are trying to change the outcome. Consistency in timing and conditions makes trends easier to interpret.

Which biomarkers should I track over time?

• The most actionable repeat markers for longevity-focused screening are A1C, ApoB, LDL, HDL, CRP, a complete metabolic panel, and a complete blood count. A1C reflects average blood glucose over the prior 2 to 3 months. ApoB measures the number of cholesterol-carrying particles linked to cardiovascular risk and is often more informative than LDL alone. CRP is a practical inflammation marker. The CMP and CBC give baseline information about liver, kidney, metabolic, and immune function.

What is Lp(a) and how often should I test it?

• Lp(a), or lipoprotein(a), is a genetically influenced cardiovascular risk marker that is not always included in standard care. Because it is largely genetic and stable across the lifespan, one careful measurement is usually enough. Davis describes it as a one-and-done test in most cases. Use the result to refine your baseline cardiovascular risk picture rather than to track week-to-week change.

Should I test before taking supplements?

• Yes, when possible. Testing before supplementing turns a guess into a decision. If a baseline shows low vitamin D, low B12, or another deficiency, you can respond more precisely. Re-testing later confirms whether the intervention worked and whether you overshot, which matters because some nutrients shift with seasonality, sun exposure, diet, and training load.