Data Field: estimated Fat and Carbs burned from time zones of heart rate

fuel sources...

Love this data field, and the fact it records the data in the fit file is great! (I assume the fit file is the summary of my run?

Out of interest, I'm on a low carb (less than 20g carbs per day) high fat diet. Weight loss going well so I'm pleased. After a hard run z4, it says I've burned 30g carbs, but it know I've not eaten than many to burn... What am I burning?

Well, even if you don't eat any carbs, you can be sure your muscles gonna burn glucose if you go higher in intensity.

Your liver has the ability to obtain glucose from proteins you eat.
Proteins are made of aminoacids, a part of them are glucogenic (the others are ketogenic, so only can become fat) and when the "amino" group is removed (and transformed to urea for excreting by your kidneys) the other part will become glucose to be used by your muscles and your brain.

Also if the athlete deplete totally the glycogen reserves (may occur even if eat carbs by regular) the body will use this metabolic route, that is a type of glyconeogenesis.
That's why I asked Peter to add calculations of carbs consumption from intensity of exercise based on the HR zones... so you can know aproximated spend of carbs to avoid the risk of total depletion.

The protein source can be "dietary", if you have eaten in a recent meal (around a couple of hours before, as much) or take aminoacids (suplements) in the hydration bottle, but usually that source is...YOUR MUSCLES.
Sure you can read lots about this if you seek for "catabolism" around the net.

Well, even if you don't eat any carbs, you can be sure your muscles gonna burn glucose if you go higher in intensity.

Your liver has the ability to obtain glucose from proteins you eat.
Proteins are made of aminoacids, a part of them are glucogenic (the others are ketogenic, so only can become fat) and when the "amino" group is removed (and transformed to urea for excreting by your kidneys) the other part will become glucose to be used by your muscles and your brain.

Also if the athlete deplete totally the glycogen reserves (may occur even if eat carbs by regular) the body will use this metabolic route, that is a type of glyconeogenesis.
That's why I asked Peter to add calculations of carbs consumption from intensity of exercise based on the HR zones... so you can know aproximated spend of carbs to avoid the risk of total depletion.

The protein source can be "dietary", if you have eaten in a recent meal (around a couple of hours before, as much) or take aminoacids (suplements) in the hydration bottle, but usually that source is...YOUR MUSCLES.
Sure you can read lots about this if you seek for "catabolism" around the net.

Thank you Susan, that's REALLY helpful! I appreciate you taking the time to reply.

Released v2.1:
* Fat and carbs total is now properly reset to 0 after ending the activity.

Graph showed but numbers don't anymore

Using 2.1 but since upgrading, the graphed still show, the actual numbers don't seem to show in the summary anymore. I'm sure they did in V2? What should I do?

the numbers never showed in the summary, it's already on my todo list to add them there, so the summary info will be in the next version ;)

for now you can mouse-over on the graph to see the numbers.

I can see the motivational value in the fat burned in grams for people who's primary reason to run is weight loss, but I'm not sure if the carbohydrate calculation is usefull, I could add it, but I don't know in which scenario's you would be using the figure.

You can't prevent depletion as you simply can not digest enough to keep up. It's not advised to digest more than 70 grams of carbo's per hour (as more is too much for the stomach to handle). (I use less than 70g/hour and even then my stomach starts complaining after a while)

From experience I can say that when I've been running for 5 hours I'm even not any more thinking of eating anything, usually I'm already glad if I can hold what I drink inside my body without having to throw up.

I regularly ride 200-300 km, but the carbs I burn (and the risk of glycogen depletion) on a ride can differ significantly significantly depending on terrain (obvious) or a headwind (less obvious). After hitting the wall once on a hilly ride, I installed a similar app on my Suunto to keep an eye on carb consumption, and it has helped me avoid this problem occurring again.

As this is no longer an "app idea" a dedicated Connect IQ Showcase thread has been created for this app, please continue the discussion in this other thread: https://forums.garmin.com/showthread.php?377823

Thanks! :)

Awesome Peter!!
Working really nice the previous ("early") version with only fat, I checked manually and working perfect.

For the users that want more accuracy, better if you use Karvonen formula using Garmin profile settings.
Karvonen method is more precise because is related to VO2 max for the most of people so I recommend it.

Go to your user profile and then HR zones configuration, choose %HRR and put your HR-Rest and set the zones as this:

Z1: 50-65
Z2: 65-75
Z3: 75-85
Z4: 95-95
Z5: 95-100(HR Max)

I will test the new version with carbs tomorrow. :D

I will give this formula a try. Is there some way to have the watch automatically enter (and keep updated) the HR Rest and HR Max figures or must you enter them manually?

Also about the zones. On Z4 I think you mean 85-95. But also I see some websites saying Z5 should be 90-100 not 95-100. For example here:

http://www.fitdigits.com/personalized-heart-rate-zones.html

Do you have some further info on this?