Garmin fenix 5S Owner's Manual

Select a cycling activity.

Hold MENU.

Select Training > FTP Guided Test.

Follow the on-screen instructions.
After you begin your ride, the device displays each step 

duration, the target, and current power data. A message 

appears when the test is complete.

After you complete the guided test, complete the cool down.
Your FTP appears as a value measured in watts per 

kilogram, your power output in watts, and a position on the 

color gauge.

Select an option:
• Select Accept to save the new FTP.
• Select Decline to keep your current FTP.

Lactate threshold is the exercise intensity at which lactate (lactic 

acid) starts to accumulate in the bloodstream. In running, it is 

the estimated level of effort or pace. When a runner exceeds the 

threshold, fatigue starts to increase at an accelerating rate. For 

experienced runners, the threshold occurs at approximately 90% 

of their maximum heart rate and between 10k and half-marathon 

race pace. For average runners, the lactate threshold often 

occurs well below 90% of maximum heart rate. Knowing your 

lactate threshold can help you determine how hard to train or 

when to push yourself during a race.
If you already know your lactate threshold heart rate value, you 

can enter it in your user profile settings (

).

This feature requires a Garmin chest heart rate monitor. Before 

you can perform the guided test, you must put on a heart rate 

monitor and pair it with your device (

). You must also have a VO2 max. estimate from a 

previous run (

).

TIP: The device requires a few runs with a chest heart rate 

monitor to get an accurate maximum heart rate value and VO2 

max. estimate.

From the watch face, select  .

Select an outdoor running activity.
GPS is required to complete the test.

Hold MENU.

Select Training > Lactate Threshold Guided Test.

Follow the on-screen instructions.

If you are training with wrist-based heart rate or a compatible 

chest heart rate monitor, you can check your recovery heart rate 

value after each activity. Recovery heart rate is the difference 

between your exercising heart rate and your heart rate two 

minutes after the exercise has stopped. For example, after a 

typical training run, you stop the timer. Your heart rate is 

140 bpm. After two minutes of no activity or cool down, your 

heart rate is 90 bpm. Your recovery heart rate is 50 bpm (140 

minus 90). Some studies have linked recovery heart rate to 

cardiac health. Higher numbers generally indicate healthier 

hearts.
TIP: For best results, you should stop moving for two minutes 

while the device calculates your recovery heart rate value. You 

can save or discard the activity after this value appears.

Training Effect measures the impact of an activity on your 

aerobic and anaerobic fitness. Training Effect accumulates 

during the activity. As the activity progresses, the Training Effect 

value increases, telling you how the activity has improved your 

fitness. Training Effect is determined by your user profile 

information, heart rate, duration, and intensity of your activity.
Aerobic Training Effect uses your heart rate to measure how the 

accumulated intensity of an exercise affects your aerobic fitness 

and indicates if the workout had a maintaining or improving 

effect on your fitness level. Your EPOC accumulated during 

exercise is mapped to a range of values that account for your 

fitness level and training habits. Steady workouts at moderate 

effort or workouts involving longer intervals (>180 sec) have a 

positive impact on your aerobic metabolism and result in an 

improved aerobic Training Effect.
Anaerobic Training Effect uses heart rate and speed (or power) 

to determine how a workout affects your ability to perform at 

very high intensity. You receive a value based on the anaerobic 

contribution to EPOC and the type of activity. Repeated high-

intensity intervals of 10 to 120 seconds have a highly beneficial 

impact on your anaerobic capability and result in an improved 

anaerobic Training Effect.
It is important to know that your Training Effect numbers (from 

0.0 to 5.0) may seem abnormally high during your first few 

activities. It takes several activities for the device to learn your 

aerobic and anaerobic fitness.

From 0.0 to 0.9

No benefit.

No benefit.

From 1.0 to 1.9

Minor benefit.

Minor benefit.

From 2.0 to 2.9

Maintains your 
aerobic fitness.

Maintains your 
anaerobic 
fitness.

From 3.0 to 3.9

Improves your 
aerobic fitness.

Improves your 
anaerobic 
fitness.

From 4.0 to 4.9

Highly improves 
your aerobic 
fitness.

Highly improves 
your anaerobic 
fitness.

5.0

Overreaching 
and potentially 
harmful without 
enough recovery 
time.

Overreaching 
and potentially 
harmful without 
enough recovery 
time.

Training effect technology is provided and supported by 

Firstbeat Technologies Ltd. For more information, go to 

You can update your gender, birth year, height, weight, heart 

rate zone, and power zone settings. The device uses this 

information to calculate accurate training data.

Hold MENU.

Select Settings > User Profile.

Select an option.

Knowing your heart rate zones can help you measure and 

improve your fitness by understanding and applying these 

principles.
• Your heart rate is a good measure of exercise intensity.
• Training in certain heart rate zones can help you improve 

cardiovascular capacity and strength.

• Knowing your heart rate zones can prevent you from 

overtraining and can decrease your risk of injury.

10

Training