Contrast: Sauna & Plunge Log

Contrast times your sauna, hot bath and cold plunge rounds — and the rest in between — so you can see exactly how long you spent where, and how your heart responded. WITH AN APPLE WATCH • On an Apple Watch Ultra or Series 10 (any watch with a water temperature sensor), getting into water starts a round on its own. Cold or hot is read from the temperature. • Heart rate for every round, with the average, min and max. • Water temperature live on your wrist, and time in each temperature range. • Water Lock comes on when you get in, so splashes don't tap the screen. • Other Apple Watch models work too: pick each round by hand. • Walk off without tapping End and the session closes itself after a long rest, timed from when you actually stopped. ON YOUR IPHONE • A calendar of your sessions — day, week or month — with each day as a ring split into hot, cold and rest. • Per-session breakdown: rounds, heart rate over the session, water temperature, time in each temperature range, and heart rate zones. Pinch to zoom the charts. • No watch? Time a session on your iPhone as you go, or log a past one: when it started, each round, and the temperatures if you know them. • Hold a session to pick several to archive or combine; swipe to archive one. APPLE HEALTH Every session is saved to Health as a Cooldown workout with its heart rate and water temperatures. Contrast also keeps its own copy of each session on your iPhone, so a workout deleted from Health stays in your history and can be saved back. Nothing leaves your devices or your own iCloud account. Settings and edits sync between your phone and watch through iCloud. ANALYSIS • Sessions and your nights: how your HRV, deep sleep, REM, total sleep, breathing rate, wrist temperature and next-morning resting heart rate compare after a session with your other nights, each against your own usual • Broken down by hot and cold, heat only or cold only, evening sessions, ending on cold, and training days with a session against training alone • How much: whether more minutes of heat or cold go with better nights • When you do it: after waking, after a workout or before bed, on a 24-hour clock, and which workouts come before • Over the months: weekly sessions next to HRV, resting heart rate and VO2 max • How your body is adapting: cold settle and cold shock at the same water temperature, heat strain at the same heat, a heat adaptation estimate, and heart rate by water temperature • Your habit: this week's heat and cold, 12 weeks at a glance, and sauna and hot-bath frequency set against long-term Finnish and Japanese studies Everything is worked out on your iPhone from your Apple Health data. Every metric shows how it's measured, its limits, and how strong the evidence is. They describe your data; they aren't a diagnosis. CONTRAST PRO Free: all watch tracking, every session saved to Apple Health, logging by hand, your last 7 days of history, your weekly sauna, cold and heat next to published research, and an explanation of every metric. Pro: your full history, the heart rate and water temperature charts, time in each temperature range, heart rate zones, sauna temperature, combining or archiving sessions, and the Analysis tab beyond your weekly amounts. Contrast Pro is a yearly subscription (new subscribers pay a reduced price for the first month), a monthly subscription (new subscribers get a 1-week free trial), or a one-time lifetime purchase. Prices for your region are shown in the app before you buy. Payment is charged to your Apple Account. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period; manage or cancel them in your Apple Account settings. Terms of Use: https://fluctusltd.info/terms/ Privacy Policy: https://fluctusltd.info/privacy/ Contrast is a timer and a record. It doesn't give medical advice. Talk to your doctor before starting cold exposure or sauna use.