Comparison

CORE Thermal Sensor vs circady

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

CORE Thermal Sensor

This app continuously monitors your core body temperature and thermal strain, providing critical data for heat training and optimal race performance. It helps athletes of all levels improve their training and achieve better results.

Highlights
  • Continuous core body temperature monitoring
  • Real-time Heat Strain Index
  • Heat Zones for training and racing
  • Heat Training Load and Adaptation Score
  • Passive heat training tracking
  • Data trends and historical analysis
  • Connectivity with sports devices
Features
Read full description

The CORE Thermal Sensor accurately measures your core body temperature and thermal strain on your body – continuously and non-invasively. Thermal data and insights are critical for facilitating safe and effective heat training and for performing optimally on race day. Designed for athletes at all levels, CORE will help to improve your training and performance in your personal adventures or races. IMPORTANT: The CORE app is designed to work with the CORE device which you can order at www.corebodytemp.com Here's how it works: • Set up your CORE sensor: connect your heart rate monitor and sports devices for optimal sensor use. • Measure your thermal vitals during training: mount the newly designed clip on your heart rate strap and snap in the CORE sensor. Shake the sensor to wake it up, wear it and track your thermal data. • Core body temperature: the interior temperature deep in your body, including organs and other tissues. A critical measure during sports, it can reach up to 40°C (104°F) during vigorous activity in hot environments. Be aware that hotter is not better – cooler is faster. • Heat Strain Index: A combination of your core body temperature and skin temperature representing the thermal strain on your body. The real-time feedback on how hard your body is working to stay cool, delivering a value from 0 (no heat strain) to around 10 (extremely high heat strain). • Heat Zones: Your Heat Strain Index divided into easy-to-use zones. Heat Zone 3 will likely lead to a performance loss, BUT it is the needed stimuli to create adaptations in your body. During heat training, strive for time in heat zone 3. During racing, stay cool and prevent a performance loss by staying in heat zone 1 or 2. • Heat Training Load: a cumulative daily metric of the heat strain on your body. A daily value of 10 out of 10 indicates ideal contribution to heat adaptations. More is not always better! • Heat Adaptation Score: Track your heat adaptations over time with effective heat training. Get a heat champion to perform best in the heat. Long-term heat training will most likely lead to improvements also in cool conditions. • Add your passive heat training: Supplementing your active heat training or general training with passive heat exposure in a sauna or hot bath. You can track your sessions in the app manually, contributing to your heat adaptation score. NOTE: do NOT take your CORE sensor into the sauna or hot environments. What else you can do in the CORE app: • Dig into the details: See a breakdown of your thermal data, and even see trends across days, weeks and months. • Share your CORE metrics with your friends through the social sharing feature, earning more kudos and likes • Connect your connectivity accounts (e.g. Garmin) to directly synchronize your data after the training. • Update your sensor to the latest firmware ensuring having the best sensor functionality. Note: CORE provides products and services designed for general fitness and training purposes. For accurate measurement readings during sports, a connection to a heart rate monitor is necessary. CORE products and services are not medical devices, not intended to treat or diagnose any disease, and should not be used as a substitute for professional medical advice, diagnosis or treatment. All content available through CORE products and services is for general informational purposes only.

About

circady

Features
Read full description

circady — Your Personal Longevity Protocol Longevity is not one habit. It is the science of keeping every system in your body performing at its best — sleep, movement, nutrition, mindfulness, social connection, and the molecules that support them all. circady tracks all six domains in one place, shows you where you stand right now, and tells you exactly when each routine is ready to be repeated. No questionnaire to fill out. HOW IT WORKS Every routine has a personal recovery window. After you log it, circady tracks the cycle: • Recovering — your body is still processing the last session • Ready — the optimal window to repeat • Needs attention — overdue; this domain is falling behind A Longevity Index score (0–100) summarizes your overall protocol coverage. The higher the score, the more domains you are actively maintaining within their ideal windows. This is supercompensation: come back when you are stronger, not on a fixed calendar date. BUILD YOUR PROTOCOL Start from expert blueprints or build from scratch: • Protocols distilled from leading longevity researchers and evidence-based guidelines • New frameworks added regularly via server-side updates — no app update needed • Fully customizable: rename, adjust recovery windows, set duration, and link to HealthKit • Up to 300 active routines across all domains SIX LONGEVITY DOMAINS • Movement — strength, HIIT, Zone 2 cardio, flexibility • Mental — meditation, journaling, breathwork, learning • Sleep — sleep schedule, no-screen wind-down, naps • Social — quality time, community, nature • Nutrition — fasting, meal timing, specific diets • Molecules — supplements, vitamins, peptides KEY FEATURES • Longevity Index — a single score (0–100) for your overall protocol health • Category tiles — per-category scores with Excellent / Very Good / Good / Fair / Needs Work labels • Daily Coach — surfaces the weakest domain each day with a targeted action tip • Streak tracking — a visual that grows through levels at 7, 14, and 21 consecutive optimal days • Timeline calendar view — see your full history at a glance • HealthKit integration — auto-complete routines from Workouts, sleep data, and more; write back to Health • Apple Watch companion — log and view your protocol from your wrist • iCloud sync — your protocol stays in sync across all your devices • Sign in with Apple — private, fast, secure account • 8 visual themes — personalize the look of your protocol tracker • Export — download your full history as CSV PRIVACY • Sign in with Apple (no password, no third-party login) • All data stored in your private iCloud container • Analytics are minimal and can be disabled in Settings • No advertising, no data selling DISCLAIMER circady is for general informational and educational purposes only. It does not provide medical advice, diagnosis, or treatment and is not a substitute for consultation with a licensed healthcare provider. Always seek the advice of a qualified physician regarding any medical condition.

Screenshots

CORE Thermal Sensor4 screens
circady4 screens

Verdict

The call

The clearest difference is iOS requirement: CORE Thermal Sensor at 15.1 against circady's 18.6. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Scorecard1 real difference · 9 level
CORE Thermal Sensor versus circady: the parameters behind the verdict, then further details
ParameterCORE Thermal Sensorcircady
PriceFreeFree
Rating2.5 (35 ratings) — better—
Positive reviews18.8% of reviews—
Number of ratings35 — better—
Update frequencyEvery 2 months—
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, Apple Watch
Requires iOS15.1 — better18.6
Further details — not scored
Size55 MB12 MB
Age rating4+17+
Developergreenteg AGMarkus Kant

In-app purchases

None

CORE Thermal Sensor

No in-app purchases

None

circady

No in-app purchases

Questions

Is CORE Thermal Sensor free?
CORE Thermal Sensor is free to download, with no in-app purchases.
Is circady free?
circady is free to download, with no in-app purchases.
Do CORE Thermal Sensor or circady have ads?
Neither CORE Thermal Sensor nor circady shows ads.

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