If you follow sports tech, your inbox fills up fast. Most of what lands is minor patches dressed up as news. This cuts through all that with one weekly post covering every feature addition across the major brands, nothing else. Trivial bug fixes are excluded. Subscribe via RSS at the5krunner.com.
Polar — Vantage V3 / Vantage M3 / Grit X2 / Grit X2 Pro / Ignite 3 / Street X — v6.0.18 — 30 September 2026
the5krunner insight: A worthwhile update across six watches, mostly for the trend graphs and the 80% charge limit.
The headline additions are seven-day trend graphs for sleep, HRV, running performance and weight, plus an 80% charge limit to protect long-term battery health. The LIGHT button also becomes a configurable Custom button. Coverage spans the Polar Vantage V3, Vantage M3, Grit X2, Grit X2 Pro, Ignite 3 and Street X.
- Seven-day trend graphs for sleep (Nightly Recharge, ANS charge, sleep duration), nightly heart rate variability, running performance index, weight and ECG test history
- Optical heart rate algorithm improvements to reduce inconsistent readings
- Charge limit of 80% to extend long-term battery life
- The LIGHT button becomes a Custom button, assignable separately for time mode and each sport profile (backlight is the default)
- Sport settings can now be changed on the watch during setup, before training or while paused
- Quick weight entry from the quick settings menu, with optional reminders
- Refreshed menu with new colours, smoother transitions and a reorganised structure
- Extra background styles for the digital watch face
Find your model’s release notes: Vantage V3 · Vantage M3 · Grit X2 Pro · Ignite 3 · Grit X2 and Street X
Hammerhead — Karoo — v1.658.2535 — 1 October 2026
the5krunner insight: A small release, only relevant if you ride with a bike radar or use Apple Health.
Hammerhead lists radar alert improvements and an extension to KGhost, its virtual rival feature, in this Karoo build. The notes give no further detail on either, so treat the specifics as unconfirmed until riders report back.
- Radar alert improvements
- KGhost extension
Full release notes: Karoo
No updates this week
Checked and nothing to report for the week ending 3 October 2026: Garmin, Amazfit, COROS, Suunto, Wahoo, Samsung, Huawei either had no release in the window or released stability and bug fix updates only.
Previous edition: #14 Deep Dive Feature Files: Week Ending 26 September 2026
Frequently Asked Questions
What is new in the latest Polar Vantage V3 firmware update?
The main additions are seven-day trend graphs for sleep, heart rate variability, running performance and weight, and an 80% charge limit. The LIGHT button can also be reassigned as a Custom button, and the optical heart rate algorithm has been improved.
Does the Polar Grit X2 Pro have a battery charge limit?
Yes. The latest update adds a charge limit of 80%, which caps charging to help the battery last longer over time.
Can I change sport settings on the Polar Vantage M3 without the phone app?
Yes. Sport settings can now be changed on the watch itself, during setup, before training or while a session is paused.
What is new in the latest Hammerhead Karoo software update?
The release lists radar alert improvements and an extension to the KGhost feature. Hammerhead has not published further detail on either.
Does the Polar Street X have a customisable button?
Yes. The LIGHT button is now a Custom button that you can assign different functions for time mode and for each sport profile, with backlight control as the default.
Last Updated on 3 October 2026 by tfk the5krunner
Small things I always use
- Garmin 90-degree charging adapter: Charges your Garmin from any USB-C cable. Essential when travelling. I use one.
- Body Glide: The blue anti-chafe stick swimmers and runners carry. I use it.
- Speedo earplugs: Fewer ear infections and no cold-water dizziness. I use them.
- Dryrobe Advance: My winter changing robe for open-water swims. I use one. A cheaper option is the AONYIYI changing robe.
- Maurten: Race fuel that stays easy on the stomach. I use them.
- Garmin charging puck: The quickest way to top up before a session. I use one.
- Injinji: Toe socks that stop rubbing, so you run more. I use them.
- Ultimate toe protectors: Stop black toenails on long runs. They work. I use them.
- Compressport R2 v2 calf sleeves: My calf sleeves of choice. I use them.
- Cellucor C4: My pre-workout before hard sessions.
- TPU tubes: Schwalbe Aerothan, Tubolito and Pirelli SmarTube. Light, tiny spares. I use all three.
- G8 insoles: Adjustable insoles that are good. I use them.
- Cycplus Cube: A 97g electric pump that gets a road tyre rideable in two minutes. I carry one. 5% off with code THE5KRUNNER.
Watches and sensors
- Polar H10: My daily driver for waking HRV.
- Polar Verity Sense: My backup arm-worn HR sensor.
- Nomad bedside charger: Charges my iPhone and Apple Watch overnight. I use it, and many of their bands.
- Train.Red: The best muscle oxygen sensor I’ve used.
- Tymewear: Accurate heart rate and reliable ventilatory zones. I use it to pace endurance rides over an hour.
- Garmin Forerunner 970: A pro-grade triathlon watch. I use this.
- Apple Watch Ultra 4: My daily smartwatch. No phone needed on rides.
- Garmin Fenix 9 Pro: I’ve just bought one.
On the bike
- Continental GP5000 for everyday riding, and Aero 111 on the front for special occasions.
- Helmets: Specialized S-Works Evade 3 for road riding, and Rudy Project Wing for TT-style races. I use both.
- Ravemen FR300: A front light that mounts under your Garmin or Wahoo. I use one.
- Wahoo TRACKR Radar: I use it on one bike and Varia on the other. They perform the same.
- Garmin Varia RTL515: Radar that warns you of cars from behind. I use this model.
- Wahoo ELEMNT Roam 3: The bike computer that’s easy to use. I use mine on most rides.
- Favero Assioma Pro RS2: Accurate power pedals that swap easily between bikes. I use this model.
Home and indoor training
- NPE Runn: Makes my basic treadmill smart, sending more accurate speed and distance to my watch and Zwift. I use it.
- Google Wifi: Keeps Zwift connected in my pain cave. I use it.
- Apple TV 4K: Zwift on the big screen. I use two.
- Google Nest Doorbell (wired, 2nd gen): My video doorbell, running in both Google Home and Apple Home. I use it.
Health, recovery and sleep
- FreeStyle Libre 3 Plus: Shows how my blood sugar responds to diet.
- hDrop: Measures my sweat loss in summer and indoors.
- Fourth Frontier Zone: Checks my heart under load in hard sessions.
- Oura Ring 5: My partner’s recovery tracker of choice.
- Kineon MOVE+: Red light therapy for niggles. It works.
- Eight Sleep: A cooling mattress cover my partner and I use nightly.
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tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID
