Training Zones Explained

Heart rate training zones explained
Zone 1. Active recovery 65% of THR
Zone 2. Endurance Zone 70 - 83% of THR
Zone 3. Tempo / Sweetspot 84 - 95% of THR
Zone 4. Lactate Threshold 95 - 105% of THR
Zone 5. Vo2 Max 106 or more of THR
Zone 6. To difficult to go by however should be sustainable for only 30 seconds
Zone 7. No parameters, efforts should be at about 10 seconds

THR = Latate Threshold Heart Rate

How to determine THR
To determine THR I recommend using indoor rollers or a trainer.   You will also need a heart rate monitor and stop watch.

Perform a 30 minute time trail at race pace. Go hard for the entire 30 minutes.  10 minutes in, press the lap button, go hard and focused for the remaining 20 minutes.  After the final 20 press the lap button.  Your average HR is your THR.  It's important to be consistent and keep up the same lever over the entire 30 minutes.  If you slow down you will get inaccurate readings.

More on THR found here ....

Heart rate training zones explained
BikeRadar.com
2014-10-24
Link: http://www.bikeradar.com/road/gear/article/heart-rate-training-zones-explained-42818/