The Foundations of Heart Rate Variability course enrolment is closing in March. There’s a discount code if you want to sign up to it (Coupon code ‘TFK’). This could be an interesting course if you’ve ever wanted to take your use of HRV to the next level.
https://hrvcourse.com/learn-more
As you may be aware, the Autonomic Nervous System (ANS) is a key player in your health and performance and one of the primary contributors to Heart Rate Variability. The problem is there are dozens of values that fall under the umbrella of “HRV” and dozens of devices/apps/systems that measure it one way or another. Oftentimes HRV is a complex, pro-like subject and many consumers take different routes to get the same data such as those looking for sporting readiness insights from WHOOP 4.
The course presents a logical progression from the ground up on the key science and mechanisms underlying HRV, as well as how to actually use this powerful biomarker in real-world situations. It is completely app/platform neutral, so whichever platform you use, you’ll have a much clearer path forward.
The curriculum is said to be geared towards health professionals, coaches, trainers, and even athletes who want to quantify and improve their own systemic condition.
As mentioned, it’s closing soon and is not open often:
https://hrvcourse.com/learn-more
Use coupon code “tfk” to get 10% off at checkout.
Last Updated on 2 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.
Reader-Powered Content
This content is not sponsored. It’s mostly me behind the labour of love, which is this site, and I appreciate everyone who supports it.
Support the site: Follow (free, fewer ads) · Subscribe (paid, ad-free) · Buy Me A Coffee ❤️
Written by real people, with AI assistance. Fact-checked and verified for originality. See the Editorial Policy. FTC: Affiliate Disclosure — some links pay commission. As an Amazon Associate, I earn from qualifying purchases.
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
I can confirm the android app is (still) free… Been shifting around hard sessions around it and seems to work…
Cheers “AS”. After about 2 years of using it you’ll get bored and want a wrist-based 246 HRV monitor…if only one, other than WHOOP, existed.
I dont use a chest strap everyday. And yet i regularly forget to take off the Polar strap I use with Elite HRV when i am up and then go running with a Suunto watch… and since i am too lazy to pair that strap on that watch i basically end up runnning with a piece of “junk” on me…. Indeed we need an optical HRV…. sigh….
or a garmin where your strap can pair simultaneously to many things 🙁 I think the new versionof Bluetooth allows one to two pairing rather than one to one (could be wrong)