METHODOLOGY
HOW WE TEST KYLA.
References covers what the published science says. This page covers what we have measured ourselves: what we found, how we found it, and what we have not measured yet.
What we measured
Results below are reported as ranges, with the conditions and sample size for each finding stated underneath.
RECOVERY
Up to 50%
Deeper heart-rate recovery between efforts at matched workload.
How we tested this
FATIGUE
Up to 25%
Lower blood lactate at matched pace.
How we tested this
OUTPUT
5 to 12%
Estimated sustainable output gain across a session of repeated efforts.
How we tested this
In detail
01The question
Does using KYLA in the rest between repeated efforts produce measurable improvements in recovery, fatigue accumulation, and sustainable output across a session?
Three markers. Heart-rate recovery between efforts. Blood lactate at matched workload. Perceived and modeled output across repeated efforts. Each addresses one part of the question. We report them separately.
02How we test
Three protocols, each designed to control for a different confound.
Within-session counterbalanced. Every second rest uses KYLA. Alternating rests within a single session. Controls for warm-up effect and accumulated fatigue, because KYLA and non-KYLA rests are interleaved.
Between-session A/B. Same athlete, same protocol, one week apart. One session without KYLA, one session with. Controls for individual variation and pacing strategy.
Longitudinal in-training. Trained athletes use KYLA across multiple weeks in their normal training, comparing against their established personal baseline. Controls for novelty and short-term placebo.
Workload is held constant where possible (SkiErg pace, treadmill speed and gradient). Heart rate is recorded continuously. Lactate is measured by finger-prick sample at standardised timing. Output is measured where the modality allows. Perceived effort is captured on the standard Borg scale.
03What we found
Across every athlete tested to date, the direction of effect has been consistently positive. We have not observed a single case of decreased recovery, increased fatigue, or no measurable change. The pattern is not yet statistically significant at current sample sizes. It has been directionally stable.
04Who tested it
Testing to date has included athletes across HYROX, mid-distance running and functional fitness.
A selection of the first 50 athletes using KYLA in pre-launch are featured below.
Jeppe Risvig. Mid-distance running. 1500m in 3:41, 10k in 29:30. Treadmill threshold sessions.
Pelayo Menendez Fernandez. HYROX Elite 15 athlete and performance coach. Three weeks of in-training observation.
Kenny Steger. HYROX Swedish record holder. Higher-intensity sessions.
Athletes tested in their normal training blocks, not in a lab. Some named with permission. Others remain private. See the first 50 →
05What we have not measured
We have not run a placebo-controlled trial against a non-cooling object of the same weight and grip.
We have not measured core temperature directly. We infer thermal load from downstream markers.
We have not measured long-term adaptation effects across training blocks longer than four weeks.
We have not tested in extreme heat or extreme cold environments.
We have not tested for effects in disciplines outside the formats described above.
These remain open questions. We will publish what we learn as testing expands.
06What we are testing next
Independent testing in collaboration with Umeå University. Aiming to start before summer 2026, with initial results expected at the end of Q3 2026. Longer studies on protocol and timing to follow.
Direct power and pace measurement on the next testing block, to convert the estimated output range into a measured one.
Counterbalanced protocols on additional athletes, to move single-athlete findings into multi-athlete confirmation.
Lactate replication across multiple sessions for each measured athlete, not just one.
Skin temperature on a subset of sessions, to anchor the mechanism in directly observed thermal load.
07The science behind it
KYLA is built on decades of peer-reviewed research into palmar heat extraction, arteriovenous anastomoses, and thermoregulation during exercise. This page documents what we have measured ourselves. The references page documents what the published science says.
This page is updated as testing expands. Last updated: 16 May 2026. For questions, requests for raw data, or partnership enquiries: hello@getkyla.com
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