Understanding healthspan through WHOOP Age and Pace of Aging

Podcast episode originally published on May 13, 2025

Healthspan is the part of your life spent healthy, mobile, and independent, and WHOOP now measures it with WHOOP Age and Pace of Aging. In this episode of the WHOOP Podcast, Emily Capodilupo, Senior Vice President of Research, Algorithms, and Data at WHOOP, explains how the feature turns nine behavior-sensitive metrics into a practical view of long-term health.

The discussion also covers why WHOOP worked with the Buck Institute for Research on Aging, why the model uses expert reference values instead of population averages, and why the gap between lifespan and healthspan deserves more attention from anyone who wants to stay strong, active, and independent later in life.

To hear Capodilupo explain why WHOOP now tracks long-term health alongside performance, watch Episode 323 of the WHOOP Podcast on YouTube.

What is healthspan, and why does WHOOP measure it?

Healthspan is the part of life lived in good health, while lifespan is the total number of years lived. Capodilupo's core argument is that modern medicine has extended lifespan faster than it has extended the years when people can move well, think clearly, and live independently.

She describes healthspan as a more useful lens for day-to-day behavior. The question is whether current habits are protecting the years when daily tasks still depend on strength, cardiovascular capacity, mobility, and cognition. That framing was influenced in part by Peter Attia's centenarian decathlon concept, which asks people to think ahead to the activities they still want to do in later life, from climbing stairs to carrying groceries to getting up from the floor.

That shift explains the design of Healthspan. WHOOP built the feature around nine repeatable, behavior-sensitive metrics that people can track week after week. Capodilupo said many biological age tools based on one-time blood or DNA measures can identify an older or younger signal, yet still leave people with an unclear next step. Healthspan focuses on metrics that are tied to long-term risk, measured repeatedly, and heavily shaped by daily behavior.

Capodilupo also tied the feature to the broader mission at WHOOP. Performance in your 20s or 30s may mean training harder or recovering better. Performance later in life can mean driving safely, climbing a flight of stairs, carrying laundry, or staying in your own home. In that sense, healthspan is still a performance question. It simply follows performance across a full life.

Capodilupo summed up the problem in one sentence:

"There's about a decade gap between health span and lifespan."

What you should take away

• Healthspan refers to the years you stay healthy, mobile, and independent, while lifespan refers to total years lived
• WHOOP built Healthspan around behaviors people can change, instead of around a one-time age test with unclear next steps
• The feature is designed to help people protect long-term function, including strength, mobility, and cardiovascular capacity later in life

How do WHOOP Age and Pace of Aging actually work?

With the goal established, the next step is understanding how WHOOP converts familiar metrics into a long-term health signal. WHOOP Age is a six-month picture of how your current physiology compares with the risk profile expected for your chronological age. Pace of Aging is the shorter-view signal that asks what would happen if your last 30 days continued for the next five months.

The model begins with nine metrics that research has linked to all-cause mortality: sleep consistency, sleep duration, time in heart rate zones 1 to 3, time in heart rate zones 4 to 5, strength activity time, steps, VO2 max, resting heart rate, and lean body mass. For each one, WHOOP established a reference value based on what experts would recommend for good health, rather than on what the average person currently does.

That reference-value choice matters. Capodilupo said population averages can be misleading because average health is different from healthy behavior. Healthspan uses a break-even point that aligns with good long-term health. Metrics above that line can make WHOOP Age younger. Metrics below that line can make it older.

She used sleep consistency to explain the logic. If a reference value were 85, someone averaging 60 would carry a risk profile that looks older, while someone averaging 95 would look younger. WHOOP applies that same structure across all nine inputs, then adds the positive and negative contributions together to arrive at WHOOP Age.

Pace of Aging solves a different problem. Six-month averages do not move much after a single good week or a rough travel stretch. To give people faster feedback, WHOOP compares the last 30 days with the longer baseline and estimates where WHOOP Age is headed if current habits continue. That is why the feature can show a strong six-month WHOOP Age even when the last month has been rough, or the opposite.

Capodilupo also described the scale in plain terms. A Pace of Aging of 1x means you are aging at the same rate as your chronological age. A score of 0 means you have effectively held WHOOP Age steady. Negative territory means the short-term trend is moving younger.

Her clearest definition in the episode was this:

"At one you're keeping pace with chronological age. At zero, you've essentially halted aging. And at negative, you're reverse aging."

Because the algorithm is transparent, the page is meant to be read from the inside out. Start with WHOOP Age, then look at Pace of Aging, then look at the nine inputs. The six-month view tells you where you are. The 30-day view tells you whether recent behavior is moving in a better direction.

For more on the scoring logic, reference values, and Pace of Aging, watch the full episode over on Youtube.

What you should take away

• WHOOP Age is based on six months of data, while Pace of Aging shows where your last 30 days are likely to move that long-term number.
• Healthspan uses expert reference values for good health, not population averages, to set the break-even point for each metric.
• A Pace of Aging of 1x means keeping pace with chronological age, 0 means holding WHOOP Age steady, and negative values indicate a younger short-term trend.

Why does WHOOP put so much weight on sleep consistency and sleep duration?

Once the model is clear, the inputs matter more than the label. Sleep comes first for a reason. Healthspan gives sleep two separate levers because timing and quantity affect long-term health through different pathways. Capodilupo argued that most people focus on hours of sleep first, even though the schedule of sleep may matter even more for healthspan.

Sleep consistency is the regularity of when you go to bed and wake up. When those times stay stable, your circadian system can anticipate food, activity, hormones, and repair processes. Capodilupo explained that this anticipation changes how efficiently the body handles daily inputs, including glucose. A consistent rhythm means the body is preparing in advance instead of reacting late.

That is one reason WHOOP treats sleep consistency as a major driver. Capodilupo said even small regressions can move WHOOP Age because the literature linking circadian disruption, poor mental health, metabolic dysfunction, and worse long-term outcomes is strong. Repeated time-zone disruption, shift work, and irregular schedules all make the metric harder to keep in the green.

She also said WHOOP data from the start of the COVID-19 pandemic showed that people with stronger sleep consistency going into that period handled stress better than people with less consistent schedules. Related WHOOP population findings on sleep timing and behavior also show up in Podcast 301: Year in Review: The Data Behind 2024's Wellness Trends.

Sleep duration still matters, but Healthspan frames it differently from daily Sleep need. Capodilupo noted that the break-even point for Healthspan is seven hours, which is lower than the sleep amount WHOOP may recommend on a given day for peak next-day performance. Healthspan asks what lowers long-term risk, while daily Sleep guidance asks what helps you feel and perform your best tomorrow.

Sleep duration also follows a curve. Capodilupo said the large longitudinal literature often shows lower risk as sleep rises toward roughly eight to nine hours, then worse associations beyond that point. Her interpretation was cautious. Very long sleep duration may reflect underlying issues such as depression, sleep apnea, or other chronic health conditions rather than sleep itself driving the risk.

Capodilupo used a concrete mechanism to explain why regular timing matters:

"When your circadian health is greater [...] the same food will have a lower spike in your blood sugar because if your body is expecting food, you've preemptively created insulin."

If you want another WHOOP discussion on behavior change around sleep and recovery, see Podcast 191: Emily Capodilupo Answers Questions on the Best Recovery Techniques, WFH, and More.

What you should take away

• WHOOP separates sleep consistency and sleep duration because schedule regularity and total sleep time affect long-term health through different mechanisms
• Sleep consistency helps set circadian timing, which affects hormonal preparation, glucose handling, and how efficiently the body responds to daily stressors
• Healthspan uses seven hours of sleep as a long-term break-even point, while daily Sleep recommendations in the WHOOP app can be higher when next-day performance is the goal
• Very long sleep duration can be a sign to look deeper at sleep quality or underlying health issues

Which exercise metrics in WHOOP have the biggest effect on healthspan?

Sleep sets the baseline, but Healthspan does not assume good sleep can make up for low fitness. The next group of metrics asks whether you are keeping enough cardiovascular and muscular reserve for later life. The exercise side of Healthspan is split into weekly time in heart rate zones 1 to 3, weekly time in zones 4 to 5, strength activity time, and VO2 max. Together, those metrics answer two long-term questions: how much do you move, and how much reserve are you keeping above the demands of daily life?

Capodilupo described moderate and high-intensity heart rate zone time as different but complementary signals. Zones 1 to 3 reflect steady cardiovascular work that supports endurance and metabolic health. Zones 4 to 5 reflect harder efforts that challenge the upper end of cardiovascular capacity and help push VO2 max higher. That upper range matters because the loss of capacity is slow enough to ignore for decades and then suddenly obvious in later life, when carrying groceries or walking up stairs becomes hard.

VO2 max is the clearest summary metric in that cluster. Capodilupo called it one of the strongest markers of cardiovascular health and one of the biggest contributors to WHOOP Age. In practical terms, VO2 max reflects how much headroom you have between ordinary daily effort and your true ceiling. The farther that ceiling falls, the closer routine life gets to maximal effort.

WHOOP estimates VO2 max passively from activity data in the app, which removes the need for repeated lab testing. Capodilupo contrasted that with traditional testing, which usually requires a specialized lab, expensive equipment, and maximal or near-maximal effort. People who want more context on how WHOOP interprets the metric can also see the related discussion in Podcast 276: Listener Q&A: Tackling the Top Summer Fitness Trends and More.

Strength activity time matters for a different reason. Capodilupo said that after age 30, adults lose about 1 percent of muscle mass per year if they are not intentionally training for it. That decline affects much more than aesthetics. Muscle helps with glucose disposal, supports basal metabolic rate, protects against frailty, and adds literal padding in a fall. Over decades, the issue becomes whether you can still get up from the floor, lift a bag of groceries, or stand up from a chair without help.

Healthspan therefore counts more than classic weightlifting. Capodilupo noted that activity types such as Strength Trainer, weightlifting, powerlifting, Pilates, yoga, functional fitness, and similar sessions can contribute to strength activity time when logged in the WHOOP app. That matters for two reasons. First, it gives people credit for work they are already doing. Second, it helps WHOOP improve future auto-detection of those activities.

On strength training, Capodilupo gave the episode's clearest long-range number:"After age 30, if you're not intentionally strength training, you will just naturally lose about 1% of your muscle mass per year."

Capodilupo spends a large part of Episode 323 connecting VO2 max, heart rate zone time, and strength work to later-life function. Watch the full episode over on Youtube

What you should take away

• WHOOP separates moderate heart rate zone time, high-intensity heart rate zone time, strength activity time, and VO2 max because each reflects a different part of long-term physical capacity
• VO2 max is one of the strongest markers in Healthspan because it reflects how much cardiovascular reserve you keep above the demands of daily life
• Strength training protects muscle mass, metabolic health, fall resilience, and the physical independence needed later in life
• Logging strength-based activities in the WHOOP app helps Healthspan reflect the work you are already doing

Why do daily steps, resting heart rate, and lean body mass still matter?

Even with the major training metrics covered, Healthspan still includes simpler signals that many people overlook. Those metrics fill important gaps in the model. Capodilupo included them because every signal of long-term health does not come from a formal workout.

Steps capture movement that never reaches formal exercise intensity. Heart rate zone targets usually begin once walking becomes purposeful enough to move heart rate out of resting territory, but a large share of daily activity lives below that line. Capodilupo called steps a proxy for general movement and said WHOOP added the metric to the app in part because the literature tying steps to all-cause mortality is now too strong to ignore. She also noted that the break-even target can shift by age, with higher step counts expected in younger adults and lower break-even levels in older adults.

Resting heart rate answers a different question: how hard does your body have to work when it is supposed to be at baseline? Lower is generally better within a healthy range because it usually reflects better cardiovascular efficiency and lower physiological strain. Capodilupo made an important clinical point here. Traditional care may not intervene unless resting heart rate gets much higher, yet long-term risk can begin moving in the wrong direction before anyone would call it a medical problem. WHOOP therefore treats rising resting heart rate as an early trajectory signal, not only as a late-stage warning.

That does not mean resting heart rate lives in isolation. It responds to fitness, sleep quality, alcohol intake, illness, stimulants, stress, and breathing habits. In the WHOOP app, the metric is also measured during sleep, when the body is most stable, which helps turn resting heart rate into a cleaner baseline marker.

The last input, lean body mass, is handled conservatively. If WHOOP does not have lean body mass data, the metric is neutral and does not change your Healthspan score. Capodilupo said WHOOP can use data from supported smart scales such as Withings or manually entered values from methods such as a DEXA scan. That choice reflects a broader design principle. Healthspan should work without extra hardware, yet when people have body composition data, the algorithm can use it.

For a deeper discussion of why body composition adds context beyond body weight alone, see Body Composition: Unlocking the Complete Look at Health. For background on the feature itself, How Healthspan on WHOOP Helps You Optimize Longevity breaks down how the app surfaces these inputs week to week.

Discussing resting heart rate, Capodilupo highlighted the gap between clinical normal and long-term risk:

"A resting heart rate in the 70s, 80s, and 90s are correlated with [...] increased risk of morbidity, mortality, you know, all cause mortality."

What you should take away

• Steps matter in Healthspan because low-intensity movement throughout the day affects long-term risk even when it does not count as a workout
• Resting heart rate can flag a worsening trajectory before it reaches a level that would trigger clinical concern in routine care
• Lean body mass is optional data in Healthspan, but when available it adds useful context about musculoskeletal and metabolic health
• WHOOP treats missing lean body mass data as neutral, so the feature still works when no body composition data is entered

How should you use Healthspan from week to week?

Once the inputs are clear, the practical question is how to use the page without overreacting to day-to-day noise. Healthspan works best as a weekly decision tool. Capodilupo repeatedly returned to the difference between the six-month view and the 30-day preview because the feature is built to reward consistency rather than short bursts.

Start with WHOOP Age. That tells you whether your recent months line up with a younger, older, or age-matched risk profile. Then look at Pace of Aging. If Pace of Aging is worse than the six-month view, recent habits are moving in the wrong direction. If it is better, recent habits are likely starting to repair the longer-term picture. Only after that should you drop into the nine inputs and look for the highest-leverage change.

Capodilupo's point was that the page is intentionally simple. Orange means the metric is pushing WHOOP Age older. Gray means roughly neutral. Green means it is moving younger. Because the inputs are behavior-sensitive, the goal is not to improve everything at once. The goal is to find the one or two orange metrics you can change most consistently. For some people that will be bedtime regularity. For others it will be steps, strength activity time, or more time in higher heart rate zones.

The six-month structure also protects people from overreacting to a bad week. Travel, a new baby, illness, or a stressful work period can push Pace of Aging up fast without erasing the longer-term habits underneath it. Capodilupo emphasized that this is a feature, not a flaw. Healthspan is supposed to reflect the score your body keeps over time.

That design is also why the behavior feedback has been strong. Capodilupo said people are responding because the page tells them exactly what to do next. There is no need to interpret a black-box biological age score that changes once or twice a year. The update cycle is frequent enough to reinforce good habits, yet slow enough to keep the signal tied to sustained behavior.

Capodilupo described the feedback she is hearing in one concise example:

"I can't tell you how many people have told me, 'I reduced my WHOOP Age by a year in 6, 8 weeks because I knew what mattered.'"

If you want to hear Capodilupo explain how people are using the page to change behavior, watch the full episode over on Youtube.

What you should take away

• WHOOP Age is the long-view score, while Pace of Aging is the short-view signal that shows where your recent habits are heading
• The most useful weekly review starts with the top-line numbers and then moves into the one or two orange inputs with the clearest behavior change opportunity
• Healthspan is designed to reward consistency, so one good day or one bad week should not be the main focus
• The feature is easiest to use when you treat it as a weekly habit check on sleep, movement, fitness, and baseline health markers

The bottom line

• Healthspan focuses on the years you stay mobile, independent, and cognitively engaged, rather than on lifespan alone
• WHOOP Age combines nine research-backed metrics over six months to show whether your current behavior profile looks younger or older than your chronological age
• Pace of Aging uses the last 30 days to show whether recent habits are likely to move WHOOP Age in a better or worse direction
• Sleep consistency is one of the strongest levers in the model because circadian regularity affects metabolic efficiency, mental resilience, and long-term risk
• VO2 max, heart rate zone time, and strength activity time matter because they preserve cardiovascular reserve and muscular capacity that later-life independence depends on
• Steps and resting heart rate add important daily context, even when formal training volume is high
• Lean body mass is optional in Healthspan, but when available it adds useful information about metabolic and musculoskeletal health

Frequently asked questions about things discussed in this episode

How does WHOOP calculate WHOOP Age?

WHOOP calculates WHOOP Age by combining nine healthspan metrics over roughly six months and comparing them with research-based reference values for long-term health.

What does WHOOP Pace of Aging mean?

WHOOP Pace of Aging shows where your recent behavior is heading by using the last 30 days to estimate how your longer-term WHOOP Age is likely to change.

How does WHOOP use sleep consistency in Healthspan?

WHOOP uses sleep consistency as a major Healthspan input because regular sleep and wake times support circadian timing, metabolic efficiency, and better long-term health.

What does WHOOP count toward strength activity time?

WHOOP counts logged strength-based activities such as Strength Trainer sessions, weightlifting, powerlifting, Pilates, yoga, and functional fitness toward strength activity time when those activities are recorded in the app.

How does WHOOP estimate VO2 max?

WHOOP estimates VO2 max from activity data in the app, giving you a passive view of cardiovascular fitness from your existing activity data.

What happens in WHOOP Healthspan if I never enter lean body mass?

WHOOP treats missing lean body mass data as neutral, so Healthspan still updates when no smart scale or body composition entry is connected.

How often should I check Healthspan in WHOOP?

WHOOP works best when Healthspan is checked weekly, because WHOOP Age is built on longer trends and Pace of Aging is meant to guide consistent behavior changes rather than day-to-day reactions.

Used well, Healthspan turns familiar WHOOP signals into a weekly check on whether your habits are protecting the years when strength, mobility, and independence matter most.