Every guide on this page answers a buying question. The upgrade guides are for people who already own a watch, tracker or bike computer and want to know whether the new model is worth the move from theirs. The comparisons put two or three named products side by side and say which to buy. The best-of guides rank a whole category. All of them are written for athletes, so they lead with what a product lets you do in training and racing rather than its specification sheet, and each ends with a verdict rather than a shrug.
Upgrade guides
Each guide takes every current model of a product line in turn and says whether its owners should move to the newest one, what they would gain, what they would lose, and when to wait. They are updated as new models launch.
- Garmin Edge upgrade guide: whether to move to the Edge 1060 from a 1050, 1040, 1030 Plus, 840, 540 or older.
- Garmin Enduro upgrade guide: Enduro 4 against the original Enduro, Enduro 2 and Enduro 3.
- Apple Watch Ultra 4 upgrade guide: from Ultra 1, 2 or 3, and from Series watches.
- Apple Watch Series 12 upgrade guide: from Series 6 through 11 and the SE.
- Coros Pace upgrade guide: Pace 4 and Pace 4 Pro against the Pace, Pace 2 and Pace 3.
- Samsung Galaxy Watch upgrade guide: Watch 9 and Ultra 2 against Watch 4 through 8.
- Fitbit tracker upgrade guide: Fitbit Edge against the Charge 6, 5, 4 and 3.
Comparisons
Two or three products, the differences that decide it, and which to buy. Predecessor comparisons come first after a launch, then the range, then rivals.
Garmin
- Edge 1060 vs Edge 1050
- Edge 1060 vs 850 vs 550, with the 1040 Solar
- Fenix 9 vs Fenix 8: which to buy
- Fenix 9 vs Fenix 9 Pro: hardware compared
- Enduro 4 vs Enduro 3
- Enduro 4 vs Fenix 9 Pro Solar
- MARQ Gen 3 vs Gen 2
- Fenix 9 vs Apple Watch Ultra 4
- Varia RearVue 820 vs RTL515
Apple Watch
- Ultra 4 vs Ultra 3
- Ultra 4 vs Series 12
- Series 12 vs Series 11
- Apple Watch Ultra 4 vs Samsung Galaxy Watch Ultra 2
Samsung
- Galaxy Watch 9 vs Galaxy Watch 8
- Galaxy Watch Ultra 2 vs Galaxy Watch Ultra
- Galaxy Watch 9 vs Galaxy Watch Ultra 2
Suunto
- Race 3S vs Race S
- Race 3S vs Race 2 vs Run 2
- Race 3S vs Garmin Forerunner 570 and 970
- Race 3S vs Coros Apex 4
- Race 3S vs Coros Pace 4 Pro
- Run 2 vs Run
Coros
Amazfit
- Balance 3 and Balance Ultra vs Balance 2
- Cheetah 2 Ultra vs Cheetah 2 Pro
- T-Rex Dual Solar vs Garmin Instinct 3 Solar
- T-Rex Dual Solar vs Garmin Fenix 9 Pro Solar
- Helio Strap Pro vs Helio Strap
Huawei
Fitbit, Whoop and recovery bands
Cycling
Best-of guides and brands compared
When the question is which product to buy in a category rather than between two named ones, the best-of guides rank the field, and the brand comparison weighs the nine sports-watch brands against each other as an owner would experience them.
- Best sports watch, with guides for triathlon, running, marathon, cycling, hiking and women’s watches.
- Best Garmin watch, with guides by Forerunner, Fenix, smartwatch, running, triathlon and budget.
- Best wearables, including recovery trackers and fitness trackers.
- Best cycling products, including cycling computers, smart trainers, power meters and heart rate monitors.
- Sports watch brands compared: the pros and cons of owning each brand.
How these guides are written
Every verdict rests on the site’s own testing where a product has been tested, and on the manufacturer’s published specification where it has not, with the two kept separate. Prices are given in pounds and dollars at launch, and a discounted outgoing model is treated as a live option rather than ignored. Buy links on these pages are affiliate links, which cost the reader nothing and fund the testing.
Explore the full resource library
This site covers endurance sport technology across a range of dedicated reference sections. Each one collects the most relevant articles, tests, and analysis on its topic in one place.
Buyer guides
- Best sports watch: tested recommendations by sport and athlete type (triathlon, running, marathon, cycling, hiking, and women)
- Best Garmin watch: Forerunner versus Fenix by series, sport, and budget
- Best wearables: fitness trackers, recovery trackers, heart rate monitors, running power meters, and female athlete tech
- Best cycling products: computers, smart trainers, power meters, and cycling heart rate monitors
- Buying guides: every upgrade guide and product comparison in one place, by brand, for owners deciding whether to move to the newest model
- Gear I use: the watches, bikes, sensors, fuel and sleep kit tfk actually trains and races with, and what his partner uses
Brand and product guides
- Amazfit: the full Amazfit range from Balance to Cheetah to T-Rex, accuracy tests, HYROX partnership, and Zepp Health analysis
- Apple Watch: athlete-first coverage of Apple Watch across running, cycling, and triathlon
- COROS: watches, features, and firmware across the full COROS range
- Garmin: the company, the platform and the full range, and the starting point for choosing across every Garmin product line
- Garmin Edge: bike computers from entry-level navigation to flagship endurance and mountain biking
- Garmin Fenix: every model, feature, and firmware development for Garmin's flagship outdoor watch
- Garmin Fenix 8 Series: which variant to buy, upgrade advice, accuracy data, and the full Fenix 8 review and firmware coverage
- Garmin Forerunner: the full Forerunner line covered from entry level to triathlon flagship
- Garmin Instinct: rugged GPS watches for endurance and adventure athletes
- Garmin Features Explained: how Garmin's metrics work, from Training Load and Body Battery to Race Predictor and HRV Status
- Google Fitbit: Fitbit Edge, Fitbit Air, Google Health, Pixel Watch and the Wear OS platform
- Polar: watches, sensors, Polar Flow and training science across the full Polar range
- Runna: coach-written running plans that adapt as you train
- Suunto: Race, Vertical, Run and the SuuntoPlus ecosystem
- Strava: features, privacy, segments, and how Strava fits into a serious training setup
- Ride with GPS: route planning, navigation and how it works alongside Strava
- Wahoo: KICKR trainers, ELEMNT bike computers, and the Wahoo ecosystem
- WHOOP: strain, recovery, sleep and the full WHOOP ecosystem
Specifications database
- Full Specifications Database: detailed spec sheets, battery life, sensor lists and generation-on-generation comparisons for current Garmin, COROS, Amazfit, Samsung, Google Fitbit, Huawei, Polar, Suunto, Wahoo and Apple Watch models
Glossary
- Sports Technology Glossary: non-branded terminology across running, cycling, swimming, triathlon, hiking, strength training, HYROX, sensors, ecosystems, and brands
Sport and topic guides
- Running Watches: how to choose by discipline (road racing, trail, track, beginner, and multisport)
- Triathlon and Multisport Technology: watches, sensors, and race-day tools for swimmers, cyclists, and runners
- HYROX: training science, race analysis, and technology for the functional fitness race format
- parkrun: technology, training, and performance for the weekly 5K
- Hiking Technology: navigation, safety, and trail tech for walkers and hikers
- Heart Rate Monitoring: optical sensors, chest straps, accuracy comparisons, and how to set training zones
- Optical Sensors (PPG): the 40 things a wrist optical sensor could measure, from heart rate to glucose, ranked by evidence
- GPS Accuracy: how satellite systems perform across brands, terrains, and conditions
- Sports Watch Battery Life: battery claims, real-world tests, and how to manage battery life across Garmin, Apple, Amazfit and COROS
- Recovery Trackers: WHOOP, Oura, and the science of readiness scoring
- Muscle Oxygen Sensors: SmO2 and NIRS explained, Train Red and Moxy compared, and the category from BSX and Humon to Garmin and WHOOP
- Female Athlete Tech: wearables, physiology, and performance for female endurance athletes, covering cycle-synced training, RED-S, HR accuracy, and VO2max
- Sports Science: peer-reviewed research on HRV, VO2max, lactate threshold, running power, wearable accuracy, and supplementation
- Testing Methodology: how this site tests GPS accuracy, heart rate, battery life, and other performance claims
Content series
- Release Radar: confirmed launches, leaks, and rumours across Garmin, Apple, COROS, Polar, Suunto, and Wahoo
- Deep Dive Feature Files: weekly firmware feature updates across all brands (bug fixes excluded)
- Fix Files: weekly firmware bug fix tracking across all brands
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.
- Beet It Sport nitrate shots: Beetroot shots I take in the days before a race. 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.
- 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.
