Garmin Edge 605 kCals

[jimboalee]

I don't want to write an essay just yet, but......

I had a brainstorm this morning after riding to work after the break.
During the break, my GF and I did some hill walking and I recorded our trips on my 605.
I was amazed to see the 'Calories' was very close to what I would expect, although the 'Calories' count when I'm cycling is MILES out.

Then I got to thinking about the Speed Zones that can be configured by the user. Do they have kCals/s attached to them???

I think they do.

Can anyone else shed light on this because as per norm, the Garmin Instruction booklet is completely hopeless.

I have sorted some ad-hoc speed zones and been for a 'normal' 5 miler. The calorie count is not so 'way out' now.
Hmmmm... Lots of tuning to do with the Speed Zones.

The Rider and Bike profiles set a 'baseline' and there must be a math calculator to affix kCals/s referenced to the baseline for each Speed Zone.

I will search the net, but I really think it's going to be a personal thing ( provided the user knows his/her calorie usage in the first place ).

Confused? I am

 

[yello]

Go Jimbo!

Yep, the Garmin manual is useless - but then so are many other manuals. They tell you no more than the button/screen does anyway. For instance, say that you have a 'Set Pendramic Roving Mode? Yes/No' option or button. You think to yourself (not unreasonably) 'wtf is pendramic roving'? So you consult the manual. It tells you that you select this option to set pendramic roving. Frikkin' useless.

Sorry, a bugbear of mine. Now back to your scheduled program.

 

[jimboalee]

Aha...

First stab at some sensible Speed Zones.

Reduced Garmin's Calorie count from TREBLE to now DOUBLE what I would consider reasonable.

Journey length 22.35 miles
Journey time 1 hr 27 mins, or 15.38 mph avg.
Calories 1402.


My estimation for a 'Lab condition' of 16 C with NO wind is 752 kCals.


Now I've got to read the minds of Garmin's Doctors to hone down the Zones to perfect reality.


PS - After all my calcs, the figure for kCals/min at 24 kmh average riding speed is 8 kCals/min. Which is what the Doctor at Audax UK and I agreed fifteen years ago.

 

[jimboalee]

A further bit of thinking.

Regarding User and Bike profiles.
Don't enter what you ARE or what the bike IS.

Enter what you are aiming to be and what bike you would like.

So instead of a 192 lb bloater, I'm going to enter for a 160 lb svelte athlete.
And instead of a 24lb Dawes, I'm going to enter a 15lb SWorks Tarmac.

This way, the calories will be ( hopefully ) reduced and therefore assist my aspirations.

 

[bonj2]

I don't think you can hold out much hope of having a cat in hell's chance of having any confidence in the calories that the Garmin reports you to have used with how many calories you have actually used.
Largely i would imagine because not everyone will burn the same amount of calories for cycling the same distance at a particular speed.
Add to this the fact that the calories you burn from doing things other than cycling, such as talking, digestion, waving your arms about, etc etc will throw the calculation's accuracy out even more.
Add to this the fact that it's pretty much impossible to calculate how many calories you take in because each portion is always going to be of a different size, and it renders the calorie a pretty useless measure.

 

[jimboalee]

I don't think you can hold out much hope of having a cat in hell's chance of having any confidence in the calories that the Garmin reports you to have used with how many calories you have actually used.
Largely i would imagine because not everyone will burn the same amount of calories for cycling the same distance at a particular speed.
Add to this the fact that the calories you burn from doing things other than cycling, such as talking, digestion, waving your arms about, etc etc will throw the calculation's accuracy out even more.
Add to this the fact that it's pretty much impossible to calculate how many calories you take in because each portion is always going to be of a different size, and it renders the calorie a pretty useless measure.

Some good points here.

If I can get the Garmin within 10% agreement with my calc sheet, I'll be happy.
At the moment, Its 100% away.

But at the end of the day ( I really hate that saying ), I will believe my Calc sheets over Garmin.

My thoughts here were "Why have I spent £180 on this thing and I'm not utilising all its funcionality".

Indeed, when I've sorted out my Cals readout, it won't transfer across to any-one else. It will be up to them to sus it out by allocating Speed Zones for their style of riding.
Oh, wonderful Garmin.

 

[dodgy]

I don't think it really matters what the numbers are, as long as the numbers for a ride of 'x' intensity are proportionally greater than a ride of 'y' intensity ('x' being the hardest / longest / fastest ride).
Your garmin will never know what way the wind is blowing or the resistance of your tyres etc etc. But, there is a nice SportsTracker plugin that makes a good stab at calculating your power output by looking at speed, HR, incline, wind speed (by integrating with weatherunderground stations).

 

[jimboalee]

OK, so it's not 'life threateningly' important, but it's fun.

 

[dodgy]

Sure is, the amount of data that a cyclist in 2009 can collect 'on the cheap' is mind blowing!

 

[jimboalee]

Latest developments.

The 'Magic' number for a leisure/tourist cyclist has always been 8 kCals/min at 20 kmh.

To get this on my Garmin, I have had to tell it a couple of lies.

1/ I have input the User Weight equivalent to me having a BMI of 21. - A skinny whippet.

2/ I have input the Bike Weight at the UCI limit of 15 lb.

The resultant kCals readout is the energy that must be consumed for the skinny whippet to maintain weight.
If I eat this number of Cals, I'm sure to lose weight.

I'll go one step further and say my 'rough' mean heart rate indicates I am using Carbs to Fat at 50/50 ratio, so I'll eat 50% of the indicated Calories and I WILL lose weight - FAT weight.

I'll go one step even further and say that my commute this morning was less than an hour, so I won't eat any more than my Basal metabolic rate.

I could, of course, enter my true weight and divide the result by four.
But by using this method, I would need to update the data in the Garmin as my weight reduces.

 

[jimboalee]

The good news is:-

After 5 years of research developing a mathematical model of me on my bike, discussion with the doctor at Audax UK and variuos tweaking through the years as information came to light, I have a math package which covers any eventuality that might befall. Weather conditions including rain and sunshine are catered for, as well as variable amounts of clothing. I am fairly confident my spreadsheet is somewhere close to reality.

Many publications on the web, Machinehead and CTC's PowerCalc are in close agreement, or should I say, I am in agreement with them.

The web based calculators are somewhat basic, so I can only presume they baseline weather and clothing as 'summer typical'.
I tend to think Garmin have done the same.

On the Edge 605, I have entered my bodyweight as 10st 0lb, an equivalent 21 BMI, and the bike weight as 15lb.

On my spreadsheet I have told it I am wearing racing lycra, the temperature is 20C and there is no wind.

My calcs and Garmin are less than 1% apart.

That, I am confident to say, is a result.

Project over. Now what do I do with it?