In this episode of the All-In podcast, Whoop CEO Will Ahmed discusses how his company uses continuous physiological monitoring to provide personalized health insights. Ahmed explains the technology behind Whoop's core metrics—including heart rate variability, sleep analysis, and strain tracking—and shares examples of how baseline deviations have helped users detect serious health conditions like cancer before symptoms appeared.
The conversation covers Whoop's evolution from a premium hardware company to a subscription-based platform, a shift that removed cost barriers and accelerated growth. Ahmed also discusses the company's regulatory challenges with the FDA over blood pressure monitoring, the role of AI in delivering personalized health guidance, and how behavioral journaling helps members understand how lifestyle choices affect their recovery and performance. With over 50 billion hours of health data collected, Whoop is positioned at the intersection of consumer wearables and proactive health management.

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Whoop distinguishes itself in the wearables market through comprehensive physiological monitoring, personalized analytics, and continuous data collection that translates into actionable insights for users.
Will Ahmed explains that heart rate variability (HRV)—the measurement of intervals between heartbeats—is central to Whoop's technology. Higher HRV indicates better health and stress adaptability, reflecting the balance between the body's activating and calming nervous system functions. Whoop tracks HRV alongside respiratory rate, resting heart rate, skin temperature, and blood oxygen levels around the clock, establishing personalized baselines for each user. Ahmed notes that HRV typically declines with age, from 80-100 in one's twenties to below 30 in the sixties, making it a valuable indicator of fitness and longevity.
The Recovery Score synthesizes HRV, sleep quality, and other physiological data into a color-coded daily metric that tells users whether they're ready for strain or need rest. Ahmed describes it as the most screenshotted feature in the app, driving user engagement and helping members make informed decisions about training and lifestyle.
Whoop delivers detailed sleep analysis tracking total hours, sleep stage proportions, circadian rhythm, and consistency. Ahmed emphasizes that consistent sleep schedules are crucial for optimizing both sleep quality and Recovery Scores. The Strain Score captures cumulative physical and psychological stress throughout the day, derived from HRV and other physiological sensors. This proprietary metric, grounded in medical research, helps users correlate their activities with recovery needs and make lifestyle adjustments to improve performance and health.
Continuous monitoring through devices like Whoop is transforming how people detect health issues before symptoms appear.
Jason Calacanis shares how his Whoop alerted him to elevated respiratory rate and skin temperature before he felt sick, leading to the discovery of lung inflammation and chest issues. Will Ahmed recounts a baseball player whose sleeping heart rate spiked from 50 to 120-130 beats per minute, prompting a doctor visit that revealed stage four lymphoma. In another case, a user's HRV drop from 100 to 50 led to a testicular cancer diagnosis.
Ahmed explains that Whoop's value increases with longitudinal data, as the device builds robust physiological baselines that help detect significant deviations indicating disease. With over 50 billion hours of physiological monitoring, Whoop identifies novel disease patterns. Calacanis notes that rapid alerts enabled him to get COVID testing and Paxlovid treatment within a day, demonstrating how early detection facilitates timely intervention.
Whoop's transformation from a premium hardware brand to a subscription-based health platform unlocked significant growth and shifted the company's focus toward continuous improvement.
Ahmed recalls that when Whoop launched in 2017 at $500, the high price limited adoption despite strong engagement from existing users. Shifting to a $15-30 monthly subscription in 2018-2019 lowered the entry barrier and transformed Whoop from a hardware business to one driven by recurring revenue. Calacanis points out that at roughly a dollar a day, Whoop offers exceptional value for personal health monitoring.
This model shift changed Whoop's incentives entirely. Rather than pushing annual hardware upgrades, Ahmed explains they now prioritize software updates and feature additions to retain members. Recent additions include ECG monitoring, AFib detection, lab integration, blood pressure insights, and HealthSpan longevity scoring. The company now focuses on engagement metrics, behavior change, and churn rates rather than hardware sales cycles.
The results speak for themselves: Whoop took 12 years to reach one million members, but added the next million in 18 months, then another million in 6 months. Ahmed notes that members wear the device an average of 23.6 hours daily, demonstrating genuine product value and sustained engagement.
Whoop's blood pressure measurement feature sparked a regulatory debate that ultimately influenced FDA policy on wellness applications.
Ahmed explains that Whoop developed a blood pressure algorithm using data from 70,000 participants but launched it as a wellness feature rather than seeking medical device clearance. The FDA responded with a warning letter, asserting that all blood pressure monitoring required regulation. Following this public disagreement and industry feedback, the FDA updated its guidelines to acknowledge wellness applications for blood pressure monitoring, allowing Whoop's feature to remain available.
Whoop pursues a hybrid strategy, seeking FDA 510k clearance for features like ECG monitoring through clinical trials while offering other features as wellness applications. Ahmed views this as a healthy exchange between innovators and regulators, with companies like Whoop helping shape policy through constructive challenge.
Whoop leverages AI to help members understand how lifestyle choices impact their physiological outcomes and provides personalized health guidance.
Whoop's journaling tool tracks over 100 daily behaviors including alcohol consumption, hydration, sleep habits, and emotional states. Ahmed notes that about 50% of members journal daily, creating rich datasets that link behaviors to outcomes. Calacanis explains that just five instances of a behavior can yield actionable insights—for example, he discovered that warm baths improve his recovery by 7%.
The data consistently show that alcohol and late meals are detrimental, with Ahmed noting a 9% negative effect from alcohol on his own recovery. Conversely, consistent bedtimes, morning sunlight, and meditation provide measurable performance boosts.
Whoop's AI coach offers personalized recommendations through a conversational interface that learns from user feedback and reinforcement learning. Calacanis describes how the coach tracked his Japan trip, recommending optimal sleep timing and caffeine avoidance for jet lag. Whoop also developed a GLP-1 medication tracker that provides tailored guidance to preserve muscle during weight loss, addressing the finding that 50% of weight lost on these drugs is muscle rather than fat.
Ahmed explains that Whoop's AI strategy integrates physiological sensor data, blood tests, medical records, and behavioral feedback for predictive modeling. This enables Whoop to shift from reactive monitoring to proactive health optimization, potentially alerting members to abnormal biomarker levels before tests are needed.
1-Page Summary
Whoop stands out in the world of health and fitness wearables for its core focus on comprehensive physiological monitoring, personalized analytics, and actionable insights, anchored in continuous data collection.
Will Ahmed explains that heart rate variability (HRV) is a central pillar of Whoop technology. HRV measures the intervals between successive heartbeats, providing insight into the balance between the sympathetic (activating) and parasympathetic (calming) branches of the autonomic nervous system. Higher HRV means greater variability between heartbeats and is associated with better health and adaptability to stress. Sympathetic activity gears the system up, elevating heart rate, blood pressure, and respiration, while parasympathetic activity calms these functions.
Ahmed describes 24/7 HRV tracking as a key innovation that Whoop brought to market, particularly after his medical research at Harvard highlighted the importance of continuous HRV observation. Alongside HRV, Whoop measures respiratory rate, resting heart rate, skin temperature, and blood oxygen saturation. This round-the-clock data collection enables the system to establish personalized physiological baselines for each user, facilitating comparison against their individual trends. Notably, HRV is also used for stress monitoring and is a powerful indicator of health and longevity, with higher or stable HRV correlating to healthier aging. As averages tend to drop by decade—from 80–100 in the twenties to below 30 in the sixties—Whoop highlights the value of maintaining or improving HRV as a sign of fitness and long-term well-being.
One of Whoop’s main features is the Recovery Score, which synthesizes HRV, sleep quality, and physiological data to gauge daily recovery and readiness to perform. Displayed as a color-coded percentage (red, yellow, green), the Recovery Score is a daily ritual for Whoop users and is described as the most screenshotted feature in the app. It tells users where they stand within their personal baseline and whether they are primed for strain or need rest. Recovery Score drives engagement, helping users make informed decisions about their training, workload, and lifestyle.
Whoop delivers in-depth sleep analysis, tracking not just overall time asleep but also sleep stage proportions (such as restorative slow-wave and REM sleep), circumstantial rhythm, and how time in bed converts into actual sleep. The system reports on when users fall asleep and wake up and measures sleep consistency—whether users maintain regular sleep-wake schedules.
Ahmed notes that most users start their day by checking their sleep data, including the sleep score and consistency metrics. Consistent sleep is emphasized as crucial for optimizing both sleep quality and the all-important Recovery Score. Whoop ...
Whoop's Core Technology and Product Features
Continuous physiological monitoring devices such as Whoop are transforming health prediction and disease detection. Both Jason Calacanis and Will Ahmed offer real-world examples illustrating how tracking metrics like respiratory rate, skin temperature, and heart rate variability (HRV) can signal underlying health conditions before symptoms are felt, allowing for early detection and intervention.
Jason Calacanis shares his experience of noticing a rise in his respiratory rate from 16 to 18 breaths per minute and an increase in his skin temperature by two degrees, detected via his Whoop device. He emphasizes the usefulness of HRV as an additional measure. Will Ahmed notes that respiratory rate is usually stable, so such an increase carries significant meaning.
Twice in a row, the Whoop device alerted Calacanis to these abnormal physiological changes before any other symptoms appeared. As a result, he became aware of an issue before he felt ill. When he later experienced chest pains, he visited the emergency room, where tests revealed lung inflammation and chest constriction, but not a heart attack. The early alert prompted him to seek medical care before his symptoms escalated.
Will Ahmed recounts a story of a fit and healthy baseball player whose sleeping heart rate, normally around 50 beats per minute, suddenly spiked to 120–130 beats per minute. Noticing the unexplained increase, the athlete visited a doctor. After further testing, he was diagnosed with stage four lymphoma. The early diagnosis enabled timely treatment and recovery.
Whoop’s value is amplified when users have long-term data, allowing the device to build a robust physiological baseline. Will Ahmed explains that this baseline helps detect any significant deviations from normal patterns, which are often early indicators of disease.
Ahmed cites an example of a long-time Whoop user who maintained a stable HRV of around 100. When his HRV abruptly dropped to 50 for an extended period, it signaled a significant problem. Follow-up medical testing led to a diagnosis of testicular cancer.
Health Prediction and Disease Detection Capabilities
Whoop's journey from a premium hardware brand for elite athletes to a broad-reaching, consumer health platform demonstrates how business model transformation can unlock new growth and drive product innovation.
Whoop launched its consumer product in 2017 with a one-time fee of $500, positioning itself as a performance brand targeting elite athletes and fitness enthusiasts. Despite high engagement from customers who did purchase the device and wore it extensively, Will Ahmed recalls they faced a persistent sales problem: relatively few people were buying Whoop due to the high upfront cost.
Realizing the barrier the high price created, Whoop shifted in 2018–2019 to a subscription model with entry plans from $15 to $30 a month, or roughly a dollar a day. This change immediately lowered the threshold to try Whoop and propelled significant growth. The company transformed from a hardware business to one driven by recurring revenue, which also appealed to investors and aligned Whoop more with consumer accessibility.
Jason Calacanis points out that, for less than a dollar a day, Whoop subscription offers one of the best investments in personal health, making advanced health monitoring affordable for a broad population.
Switching to subscriptions shifted Whoop’s business incentives. Ahmed explains they became deeply focused on innovating for and retaining existing members rather than cycling yearly hardware releases. Rather than pushing annual device upgrades, Whoop only launches new hardware when it offers major improvements, and instead regularly updates the membership experience and software capabilities.
This focus has resulted in continual enhancements for active subscribers. Over the past 18 months, Whoop introduced features such as ECG monitoring, atrial fibrillation (AFib) detection, advanced lab integration with blood work, daily Blood Pressure Insights (even aiming to replace the standard cuff by calibration), and HealthSpan longevity scoring, allowing members to get new health functionality with the same hardware.
The subscription model also changed Whoop’s internal culture and success metrics. Ahmed and Calacanis emphasize that the c ...
Business Model Evolution and Growth Strategy
Whoop developed an algorithm for wrist-based blood pressure measurement using data collected from a 70,000-person study in which participants uploaded their blood pressure readings daily for several weeks. This dataset allowed Whoop to train its algorithm alongside other physiological data. Will Ahmed, CEO of Whoop, explains that historically, the FDA has viewed blood pressure measurement as a physiological function requiring regulation as a “medical device.” In contrast, heart rate monitoring is only treated as a medical device when used for medical purposes such as detecting atrial fibrillation or predicting heart attacks, but not when used for wellness applications like exercise or sleep.
Whoop launched its blood pressure insights as a wellness feature, arguing that blood pressure could have wellness applications and should not always be regulated as a medical device. However, the FDA maintained that all blood pressure monitoring required regulation and responded by sending Whoop a warning letter. This prompted a very public disagreement between Whoop and the FDA, highlighting the tension over how products should be classified.
Following this regulatory conflict and feedback from both industry and companies like Whoop, the FDA updated its guidelines to acknowledge that blood pressure monitoring can also serve wellness purposes. As a result, Whoop’s blood pressure insights feature remains available to consumers. Will Ahmed reflects on the process as a healthy exchange between innovators and regulators, suggesting that innovative companies like Whoop play a key role in shaping policy by navigating and challenging regulatory disagreements.
Fda Regulation and Medical Device Classification
Whoop leverages AI and user-driven behavioral tracking to personalize health optimization. Through journaling integration, insight analysis, an adaptive AI coach, and predictive modeling, Whoop helps members understand how lifestyle decisions influence their physiological outcomes and provides tailored health guidance.
Whoop's platform offers members a comprehensive journaling tool that tracks over 100 daily behaviors such as alcohol consumption, hydration, meal timing, sleep, meditation, travel, supplement use, and emotional states. Will Ahmed explains that popular journal items include logging alcohol intake, hydration status, travel, and daily mood indicators like happiness, sadness, or stress. About 50% of Whoop members journal daily, creating a rich data set that links behaviors to physiological and health outcomes.
Jason Calacanis notes that by consistently completing the journal—whether every day or a few times per week—users receive more valuable insights. Whoop prompts members each morning to log behaviors and then correlates these behaviors with changes in recovery scores. As Calacanis highlights, just five 'yes' and five 'no' entries for a specific behavior can yield actionable insights into how, for instance, creatine usage or other habits impact recovery.
The AI-driven insights Whoop provides can reveal counterintuitive and highly individualized relationships between specific behaviors and performance. For example, Calacanis discovered that taking warm baths—a practice he originally resisted—improves his recovery score by 7%. Will Ahmed adds that features like sauna use or cold plunge may have more neutral effects, though individual responses and personal preferences vary.
Conversely, the data consistently show that certain behaviors—particularly alcohol consumption and eating late meals—are strongly detrimental. Ahmed details that alcohol produces a negative 9% effect on his own recovery, and late meals (within three hours of bedtime) impair sleep quality and recovery across the user population, as digestion interferes with restful sleep.
In terms of positive influences, Calacanis lists consistent bedtime, morning sunlight exposure, caffeine avoidance, creatine supplementation, and meditation as behaviors that each provide measurable boosts to recovery and physiological performance.
Whoop's AI coach provides personalized engagement through a conversational interface, logging user interactions for contextual understanding. Initially simple, the AI coach has become increasingly sophisticated, adapting to user routines such as international travel. Calacanis describes how, during a trip to Japan, the AI coach tracked changes in his sleep patterns and activity, recommending optimal sleep timing and caffeine avoidance to mitigate jet lag.
The AI coach requests user inputs regarding goals and evolving routines, then delivers bespoke training and recovery recommendations. It learns and improves through both user feedback and reinforcement learning, enabling deeper personalization with each interaction. For example, it might notice when a user's sleep is misaligned during travel and prompt for relevant details to maintain accurate data and provide tailored guidance.
Recognizing the widespread need for circadian rhythm adjustment during international travel, Whoop formed a dedicated team to optimize guidance for this high-frequency use case. The AI provides specific recommendations related to sleep timing, light exposure, an ...
Ai-powered Personalization and Behavioral Insights
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