Actionable
Know when, what and how much to drink
HDROP GEN 2
Reusable sweat sensor. Real-time sweat testing.
Track sweat loss, sweat rate and sodium loss as you train, with one reusable hydration sensor built for running, cycling and race day.
Fully reusableNo disposable patchesNo subscription required
Explore hDropPartners & Clients:
Your body. Your data.
Nail Your Personalized Hydration Plan
Muscle cramps, heat exhaustion, fatigue… Dehydration can impact your well-being before you even realize it and impair your athletic performance. The hDrop biosensor analyzes the biomarkers on your sweat and transform them into valuable data to take care of your performance.
Affordable & Sustainable
Say goodbye to disposable patches
Flexible
Clip it to your heart rate monitor, or use our arm-straps
Measured during real exerciseThe science behind the signal
Independently Scientifically Validated
hDrop is the only reusable sweat sensor that has been independently scientifically evaluated during real exercise in the heat, demonstrating ~92% accuracy for sweat-loss tracking and ~87% accuracy for sweat sodium-loss across running and cycling trials. Since that 2025 study, our team has continued improving the sensor and algorithms, with ongoing validation showing preliminary sodium-concentration accuracy approaching 95%.
~92% Sweat-loss tracking
~87% Sweat sodium-loss
Reusable sweat sensor. No disposable patches.
One sensor.
Session after session.
Wipe it. Clip it. Go!
hDrop offers a new slick design, purposely crafted to fit your current workflow, being flexible with the tools and clothing you normally wear during your activities.
Select a view to explore the sensor.
Reusable Electrode Sensor
Reusable electrode sensor Sweat loss tracker Sweat rate sensor Sodium and Potassium losses Temperature monitor Easy to wear Rechargeable battery Integrates to your workflow
Sweat, decoded
What does the hDrop sweat sensor measure?
hDrop gives you real-time insights into your fluid loss, sweat rate, sodium loss, potassium loss, and sweat composition, helping you understand what your body is losing during training or racing.
hDrop measures sweat rate and electrolytes through its reusable electrode sensor and analog readings from your sweat. These physical measurements are used to calculate fluid and electrolyte losses throughout your session.
Total Fluid Loss34.6fl oz
Total amount of fluid lost through sweat during your active activity.
Avg Sweat Rate38.2fl oz/haverage
Your average rate of fluid loss per hour during intense activity.
Sodium Loss963mg
Sodium lost through sweat during your active activity.
Potassium Loss126mg
Potassium lost through sweat during your active activity.
Sodium Conc.28mg/fl ozaverage
Sodium concentration in your sweat during intense activity.
Sweat Onset1.2minquick onset
Time until first sweat drop was detected during intense activity.
Personalize your hydration preparation and recovery
Fluid loss
This refers to how much liquid your body loses when you exercise. Used to calculate hydration needs.
Sweat rate
This is how much you sweat in an hour. It's useful for figuring out your fluid loss.
Sodium loss
This is the amount of salt that you lose when you sweat. Used to calculate electrolyte needs.
The hDrop app
Get individualized hydration tips based on sports science
The hDrop app
Morning Activity
54:20
Sensor location: Chest
Total Fluid Loss34.6fl oz
Total amount of fluid lost through sweat during your active activity.
Avg Sweat Rate38.2fl oz/haverage
Your average rate of fluid loss per hour during intense activity.
Sodium Loss963mg
Sodium lost through sweat during your active activity.
Potassium Loss126mg
Potassium lost through sweat during your active activity.
Sodium Conc.28mg/fl ozaverage
Sodium concentration in your sweat during intense activity.
Sweat Onset1.2minquick onset
Time until first sweat drop was detected during intense activity.
Hydration Recovery Plan
- Fluid Intake Goal
- 13.6fl oz
- Sodium Target
- 457mg
Recovery Timeline
- First 30 Minutes
Consume 1/3 of your recommended fluid intake with electrolytes
- 1–2 Hours
Take another 1/3 of fluids along with a light meal containing salt
- 2–4 Hours
Complete your recovery with the remaining fluid intake
The device delivers personal results based on your sweat, workout type, and body physiology. Linked with our hDrop App, it allows you to craft a personalized hydration plan.
Know what you’re losing.
Your sweat data, your preparation, your recovery. Together in the hDrop app for iOS and Android.
Make it personal
Are you getting the right amount of sodium?
hDrop compares your sweat sodium concentration with popular hydration drinks, helping you see whether your current drink is too low, too high, or a close match for your needs.
Hydrate smarter with personalized sweat and hydration insights.
- Your current drink
- 533 mg/L
- Avg. sweat sodium
- 942 mg/L
Understand the difference.
Too little sodiumToo much sodium
Every session tells a story
Track sweat sodium concentration throughout your workout.
Follow how your sweat sodium concentration changes during training and racing, alongside your fluid- and sodium-loss data. Build a sweat profile across different sessions, intensities and conditions, not just a single test.
Know when your body starts sweating Track electrolyte changes in your sweat continuously Discover your hDrop hydration baseline and try to keep it inside your zone
Minutes
hDrop™ Sweat Zones
A new feature that allows you to understand your hydration in an easy and intuitive way during exercise. It is a tool to help you stay aware of your status, complement your hydration strategy, and be more prepared. It does not, in any case, replace the advice of a professional.
hDrop ScoreIllustrative
Minutes
Target ZoneConcentrated ZoneDiluted Zone
Concentrated Zone
This zone indicates that your sweat has less water and more salt. It could mean you might not be drinking enough plain water.
Target Zone
This is the zone where the concentration of salts and the volume of your sweat are balanced, indicating that your sweat levels are within your regular range.
Diluted Zone
This zone shows that your sweat has more water than usual. It suggest you might be drinking too much plain water, diluting the salts in your body and potentially needing more electrolytes.
Fits the way you train
Live sweat data on compatible training devices.
In-workout insights.
Post-session perspective.
Live data · Watches & Edge
See sweat loss, sodium loss and hDrop Score on compatible Garmin devices. Start in the hDrop app, connect to Garmin, then leave your phone behind during your workout.
Garmin setup guide Check compatible Garmin models
Live data · Karoo 2 & Karoo
Track sweat loss, sodium loss and hDrop Score during your ride. Install the hDrop Extension from the Extensions Library on Karoo 2 or the current Karoo.
Hammerhead setup guide
Live data · ACE, BOLT 3 & ROAM 3
View fluid and sodium loss live and record them in your ride’s FIT file. Start in the hDrop app, then connect to ELEMNT. Older ELEMNT generations are not supported.
Wahoo setup & software requirementsFor hDrop Gen 2. Start and finish recordings through the hDrop app; reconnect after using an external display for your complete session analysis. See each setup guide for requirements.
Post-session syncing
Your sweat data, alongside your training.
Link your accounts to automatically send completed hDrop sessions to your TrainingPeaks calendar as a Metrics card and a note on the matching workout. Garmin-recorded hydration data can also appear in Advanced Graphs through the hDrop Scores data field.
Set up TrainingPeaks syncingThe hDrop community
Athletes are using hDrop to stop guessing their hydration.
4.8 / 5 Based on customer reviews
Real customer feedback highlights why athletes use hDrop for sweat loss, sodium insights, training context, and personalized hydration planning.
Mentions & Awards
Made for your everyday
Operational Modes for our Sweat Sensor
Explore the ways to use your hDrop.
Thumb Test
Place your thumb on the sensor for 80 seconds and receive an immediate range hydration score, offering an estimated snapshot of your current hydration status. (Good, Medium, Low)
Light Activity
Designed for individuals engaged in less strenuous activities like working at a desk, resting, or taking a light walk. Simply place your hDrop on your upper arm, wait to allow sweat capture, and then receive notifications.
Intense Activity
This mode provides real-time feedback on sweat rate, sodium and potassium loss, and other crucial metrics, helping you understand how your fluid intake affects your performance.
Your sweat sensor questions, answered.
Who is hDrop designed for?
hDrop is designed for athletic training and racing. It is not intended for sedentary hydration monitoring, elder-care monitoring, or diagnosing, treating, or managing medical conditions.
Does hDrop need disposable patches?
No. hDrop is fully reusable and does not require disposable patches.
Does it require a subscription?
No, hDrop does not require a subscription.
How is repeated sweat testing different from a one-off test?
hDrop records your sweat throughout your activity. Use the same sensor across runs, rides and changing conditions to compare your sweat-rate and electrolyte data over time, building a sweat profile from your own training. Explore our guide to sweat testing.
How does hDrop measure sweat rate and electrolytes?
hDrop measures sweat rate and electrolytes using a reusable electrode sensor in contact with your skin. The sensor captures analog readings from your sweat; hDrop processes these physical measurements to calculate fluid and electrolyte losses throughout your activity. Correct placement and consistent skin contact help maintain reliable readings. Learn how hDrop’s electrode sensor works.
How do I clean and reuse the sensor?
Gently clean the electrode surface with an alcohol prep pad and let it dry. Do not use water on the sensor. Remove the straps before hand-washing them with water and soap, and let them dry completely before reattaching them.
Which watches and bike computers can I use?
hDrop Gen 2 supports live data on compatible Garmin watches and Edge devices, Hammerhead Karoo 2 and the current Karoo, and Wahoo ELEMNT ACE, BOLT 3 and ROAM 3. TrainingPeaks receives completed-session data rather than a live display. Check the device-specific setup guides for model and software requirements.
Does it work without internet?
The hDrop app supports offline mode. Start and complete your activity with your phone, then upload the data when connectivity returns.
Where can I learn more before buying?
Explore the hDrop Gen 2 product details or contact our team.
Your next session starts here
Start monitoring your hydration today
Reusable. Rechargeable. Ready to go again.
