Wahoo Fitness announced on 2 June 2026 that a firmware update for its ELEMNT V3 bike computers will stream live sweat and sodium data onto the head unit, putting hydration alongside power and heart rate as a real-time race metric for the first time.
The update adds native support for four physiology sensors – CORE, FLOWBIO, Tymewear and hDrop – but the headline development is on the sweat side: FLOWBIO's real-time feed delivers exactly the capability the company had been promising.
We were first to report in April that live sweat measurement was heading for the WorldTour, when FLOWBIO confirmed its Project RT real-time feature was close to launch. The pitch then was that hydration and sodium loss would move from post-ride summaries into live data during racing, joining power and heart rate as a metric riders, teams and eventually spectators could read in the moment.
CEO Stefan van der Fluit illustrated the stakes with data from a UCI WorldTour rider at Milan-Sanremo, who lost 5.1g of sodium and 4.3 litres of water over the race – more than two days of typical guideline intake in a single effort. Displaying that data on a head unit was described at the time as the first technical step. This Wahoo integration is that step going live.
The firmware requires no new hardware. FLOWBIO's sensor measures fluid and sodium loss continuously during exercise and streams readings to the Wahoo screen in real time, with output feeding its Advanced Hydration Intelligence (AHi) platform for pre-ride, in-ride and post-ride decisions. The 10g sensor can be worn on the upper arm or clipped to a standard heart rate chest strap. FLOWBIO confirmed its real-time stream will launch in late June 2026.
The FLOWBIO sensor
"Hydration has been one of the last parts of endurance training to rely on guesswork," said van der Fluit. "Power, heart rate and pacing are all measured and visible to the rider during the session. Sweat loss has typically been estimated afterwards, if it is measured at all." Bringing the data onto the ELEMNT V3, he said, lets the rider see what their body is actually losing in the same place as every other training variable, and respond to it during the ride.
FLOWBIO says its sensor has been adopted by WorldTour teams and performance centres including Red Bull High Performance in Salzburg. A peer-reviewed validation study published in Frontiers in Physiology found the sensor's estimated whole-body sweat loss was not statistically different from scale-based measurement in test conditions, though the authors cautioned that sweat sodium concentration results should not yet be treated as equivalent to laboratory-grade analysis. A separate lab review by Precision Fuel & Hydration found the FLOWBIO S1 underestimated sweat rate by 0.44 litres per hour and overestimated sweat sodium concentration by 413 milligrams per litre in its testing, a reminder that real-time numbers on the bars still carry meaningful error bars.
FLOWBIO is not the only sweat sensor in the update. hDrop also gains native ELEMNT support, translating sweat composition into real-time hydration and electrolyte guidance, with co-founder Adria Abella framing sweat as "the next biosensing signal" for in-the-moment performance decisions.
The remaining two integrations sit outside hydration: CORE adds continuous, non-invasive core body temperature and heat-strain readings for pacing and heat management, while Tymewear's VitalPro measures breathing to flag ventilatory thresholds for setting individualised training zones.
All four integrations are scheduled to go live later in June across the ELEMNT BOLT 3, ROAM 3 and ACE, for existing and future owners.
Photo credits: FLOWBIO
