Wearable thermal intelligence for sleep, recovery, and performance
Master your body's thermal rhythms and learn when to rest, recover or push.
Join a community of athletes and fitness enthusiasts.
Wearable thermal intelligence for sleep, recovery, and performance
Master your body's thermal rhythms and learn when to rest, recover or push.
Join a community of athletes and fitness enthusiasts.
Pro-level thermal science made accessible
In elite sports, heat patterns are measured with infrared cameras to monitor recovery and performance.
Larcz makes this wearable; giving you pro-level science you can use everyday.
Train and recover in tune with your body
Each morning, guided by your thermal rhythms and body clock, Larcz highlights when your body is primed for endurance or strength training, and when it's best prepared for sleep and recovery.
→ Know your optimal training windows
→ Identify when your body needs recovery
→ Align effort with readiness to train smarter
Learn the nuances of your training
Go beyond basic fitness tracking. Larcz translates your thermal patterns into actionable signals that guide adjustments to pacing, hydration, and cooling to elevate performance.
→ Real-time performance optimization
→ Track cooling efficiency post-workout
→ Prevent overheating before it impacts results
Discover your left–right balance
Larcz’s dual-wearable system measures power output on each side of your body, revealing how evenly your muscles are working. By comparing left and right muscle power, you can identify imbalances that affect efficiency, fatigue, and injury risk.
→ Correct asymmetries before they cause injury
→ Refine technique with objective feedback
→ Train more effectively with balanced development
Track your training load and performance
Larcz translates your body’s heat signatures into power and energy metrics, providing a clear view of training load and efficiency as it builds over time.
→ Quantify training intensity objectively
→ Track efficiency improvements over time
→ Balance load and recovery effectively
Decode the subtle shifts in thermal balance that occur while you sleep
Larcz tracks how your heat signatures change through the night, revealing signs of thermal imbalance that may affect sleep quality and recovery.
→ See how efficiently your body releases heat during sleep
→ Identify periods of thermal stress that may disrupt rest
→ Understand which changes support better thermal balance
Two pods, worn together, enable accurate circadian and heat flow tracking
Larcz has two tracking modes. In both modes, you wear two pods at the same time to track temperature and heat signatures at different zones of your body and how heat moves across those zones.
Circadian mode
Wear one pod on your chest and one on your arm. The chest pod captures temperature signals from the core region, while the arm pod measures surface temperature changes.
Together, they reveal how heat moves through your body during training, recovery, and rest.
Muscle balance mode
Wear two pods on matching muscle groups (left and right), such as your biceps or quads.
By comparing heat signatures and power output on each side, you can spot muscle imbalance, helping you train smarter by adjusting load, technique, or recovery.
Built for comfortable wear, day to night
What is included
Larcz pods
Discreet, lightweight pods with a refined form factor designed for all-day and all-night comfort.
Smart dock
An elegantly designed dock that charges and protects your pods while quietly monitoring your bedroom environment.
Hypoallergenic patches
Ultra-soft, breathable patches engineered for secure, comfortable wear for up to seven days.
Charging cable
USB-C to USB-C charging cable for fast and reliable charging.
Who Larcz is designed for
Made for athletes and performance-driven individuals who want to improve performance, track training load and recovery, and use sleep and circadian timing to gain a competitive edge.
Improve athletic performance
Optimize performance and recovery by aligning training and sleep with your body's natural rhythms. Track key performance and readiness signals to train when your body is primed.
Manage muscle balance and recovery
Identify muscle imbalances and asymmetries using heat and power insights. Refine training load, technique, and recovery to support balanced, efficient performance.
Understand what’s disrupting sleep and recovery
Reveal what's interfering with recovery, from circadian misalignment to thermal inefficiency, so you can correct timing and restore high-quality rest.
Latest insights
Science, stories, and strategies from the world of thermal performance
Mar 8, 2026
Is your sleep and fitness tracker misleading you?
Sleep, recovery, and performance are whole-body processes. Here's why multi-zone tracking matters
Feb 15, 2026
Your clock is your superpower: How circadian rhythm drives better sleep and performance
Timing beats effort. When you train or sleep in sync with your body clock, everything becomes easier.
Jan 6, 2026
Unlocking the hidden language of heat for smarter sleep and training
Heat is your most honest performance metric—learn to read your thermal rhythm to train and recover smarter.
Common questions, clearly explained
Larcz is a dual-wearable system designed for continuous, everyday use. Larcz reads your heat signatures across key zones of your body throughout the day, building a thermal profile unique to you. From this, it reveals your body clock and readiness windows for sleep, recovery, energy, and performance, so you can time daily activities in sync with your circadian rhythm.
Interested in exploring thermal intelligence for performance and recovery?
Reach out to learn more about early access, partnerships, or media.