A lot has been made of the importance of the heart rate zone you train in. Mostly that zone 2 is good & that zone 3 is bad! A grey zone, which should be avoided. But why? What’s the reason for this? And should you avoid the grey zone when trying to improve your fitness levels? Mark is here to investigate!

Useful Links
Submit your Photo and Video to us 👉 https://gtn.io/UPLOAD
Check out the GTN Shop 👉 https://gtn.io/TeamKit
GTN Training Plans 👉 https://gcn.eu/gtntp

Watch more on GTN...
📹 Why Is Everyone Talking About Zone 2?! 👉 https://youtu.be/tqTYJg2mnT0
📹 Watch our Editor’s Choice Playlist 👉 https://gtn.io/editorschoice
📹 Watch our weekly show, The GTN Show 👉 https://gtn.io/GTNshowPlaylist

Photos: © Triathlon / Getty Images

🎵 Music - licensed by Epidemic Sound / Artlist 🎵
Ten Days - Dylan Sitts
Still No Wifi - Dylan Sitts
368 - Jobii
The Aftermath - Dylan Sitts

#gtn #triathlon #swimbikerun #swim #bike #run #fitness #health

The Global Triathlon Network (GTN) is the world's biggest triathlon YouTube channel, with new videos every day! GTN is for anyone who loves triathlon: from seasoned triathletes to first-timers – and everyone in between!

With the help of our former pro and Olympic medal-winning team, we’re here to inform, entertain and inspire you to become a better triathlete; including videos on:

- How to swim, bike, and run faster with expert knowledge
- Try our session ideas
- Investigations into wide-ranging topics
- The best triathlon bike tech and gear with pro-know-how
- In-depth, entertaining features from the heart of the sport
- Chat, opinion and interact with us across the channel and on social media!

Join us on YouTube’s best triathlon channel to get closer to the sport and to become a better, faster and fitter triathlete!

Welcome to the Global Triathlon Network.

Thanks to our sponsors:
Canyon bikes: http://gtn.io/canyon-bikes
THEMAGIC5: https://gtn.io/TheMagic5
MET Helmets: https://gtn.io/MET
ON Running: http://gtn.io/On-Running
Orca: http://gtn.io/Orca
Park Tool: http://gtn.io/parktool
Precision Fuel & Hydration: https://gtn.io/PrecisionHydration
Selle Italia: https://gtn.io/SelleItalia
Trimtex: https://gtn.io/Trimtex
Wahoo: https://gtn.io/Wahoo
Zwift: http://gtn.io/zwift

Watch our sister channels:
Global Cycling Network - https://www.youtube.com/gcn
GCN Tech - https://www.youtube.com/gcntech
GCN Racing - https://www.youtube.com/gcnracing
GCN Italia - https://www.youtube.com/gcnitalia
GCN en Espanol - https://www.youtube.com/gcnenespanol
GCN auf Deutsch - https://www.youtube.com/gcnaufdeutsch
GCN en Francais - https://www.youtube.com/gcnenfrancais
GCN Japan - https://www.youtube.com/gcnjapan
GCN Training - https://www.youtube.com/gcntraining
Global Mountain Bike Network - https://youtube.com/gmbn
GMBN Racing - https://gmbn.eu/GMBNracing
GMBN Tech - https://www.youtube.com/gmbntech
Electric Mountain Bike Network - https://www.youtube.com/embn