Once you have done the two step test and properly determined your Lactate Threshold you will be able to set your training zones as follows:
Equip your watch (and connect your heart rate straps) to record data for zone training.
Re-testing lactate threshold every 2-3 months (depending on the fitness age of the athlete) is required as zones will need adjusting as fitness improves, meaning your field tested data stays accurate and allows for fully robust training sessions.
As you improve your aerobic fitness, you would expect your average heart rate during a 30 minute lactate threshold time trial to decrease.
This is because the heart becomes more efficient at pumping blood and oxygenating the muscles as cardiovascular fitness increases.
There are a few key reasons why heart rate at lactate threshold pace decreases with training:
The cumulative effect is that the cardiovascular system can sustain a given pace with less effort and lower heart rate.
So if you see your lactate threshold heart rate dropping over time, it’s a good sign you are building robust cardiovascular fitness.