Four pillars of steadiness
Build resilience through consistent practice across breathing, cold, heat, and stillness.
Guided routines, zero friction
Start with contrast therapy templates or build your own custom flows. Cold to heat to stillness—SISU sequences your practices seamlessly.
Customizable · Repeatable · Designed to remove friction
Your Steadiness Score
Track your progress across all four pillars of practice.
Every feature intentional
Minimal, beautiful, distraction-free. Every screen is designed to keep you present in your practice.
Apple Watch Integration
Heart rate syncs automatically via HealthKit. See your body's real-time response to practice.
Guided Audio Tours
Voice guidance keeps you focused during sessions. Choose from calming soundscapes.
Progress Tracking
Your Steadiness Score reflects consistency. See trends and insights as your practice deepens.
Got questions?
Sisu is a Finnish concept meaning calm determination and resilience in the face of adversity. Our app helps you build this quality through guided breathing exercises, cold exposure tracking, heat training, and stillness meditation. It's about developing steady composure through consistent practice.
Flows let you build custom practice routines by combining multiple practices into a single sequence. Choose from contrast therapy templates like Basic Contrast, Nordic Style, or Athletic Recovery—or create your own. Set durations for each step, arrange the order, and save your flow. When you run a flow, SISU plays each practice seamlessly in sequence with optional rest periods between steps.
Weekly Goals let you set target minutes for each discipline—Cold, Heat, Breathing, and Stillness. Choose from protocol presets like Huberman (11 min cold), Moderate (15 min), or Advanced (25 min), or set custom targets. Progress rings show your weekly completion without streak pressure—it's about sustainable rhythm, not daily perfection.
Practice Finder is a map-based tool that helps you discover cold plunges, saunas, float tanks, and wellness centers near you. When you're not sure what to do or where to practice, open the finder and see what's available nearby. It's a quick way to choose what to do when you don't know what you need.
Your Steadiness Score reflects your consistency and engagement across all four practice types: breathing, cold, heat, and stillness. Regular practice builds your score over time. The score isn't about perfection—it's about showing up consistently and building resilience.
SISU includes three core breathing practices: Paced Breathing (4-6 calming breaths for daily relaxation), Box Breathing (4-4-4-4 square breath for focus and stress relief), and Cyclic Breathing (30 breaths + hold for energy and resilience). Each includes optional guided audio and calming soundscapes.
No, SISU works great without a watch. Heart rate monitoring is an optional enhancement that provides additional insights during your sessions. If you have an Apple Watch, heart rate data will sync automatically via HealthKit.
Yes. Your session data is stored securely in the cloud using Supabase with strict row-level security—only you can access your data. We never sell data or share it with third parties. Biometric data captured during sessions (like heart rate) syncs to enable cross-device access, but raw HealthKit data remains under Apple's control on your device.
