Quantcast
    MAIN INDEX RULES & LEGEND LOG IN  

Slowtwitch Forums: Triathlon Forum:
Garmin 405 Calorie Counter - How Accurate?

 

   


flipmypancake

Mar 15, 10 14:11

Post #1 of 11 (4162 views)
Garmin 405 Calorie Counter - How Accurate? Quote | Reply

So I did a 50 mile ride with 4500 ft of climbing yesterday in 3 hours with an average HR of 133. My Garmin says that I burned over 3300 calories? I'm highly doubting that to be the case. I know that through testing I burn 2200 calories doing nothng and another 250 through minimum activity for a base of 2450 calories a day. I'm trying to drop 10 lbs so I'm trying to have a caloric deficit of around 3500 per week which is about 500 calories a day. So correct me if I'm wrong but if I really burned 3300 calories then I could have taken in 5,250 calories yesterday and still been at a deficit? That seems a bit silly so I'm thinking that my Garmin 405 calorie counter is wrong when I ride. I'm 6'0 and about 190 to 195. My weight and height on my Garmin are correctly inputed. If anyone has a better way to estimate calories burned while running, riding and swimming that would be great! Ironman Canada will be my first Ironman and I'm really trying to nail the nutrition but I'm finding it very, very difficult to figure out how much to eat. I know when to eat (4 hrs before, 30 mins after) and what to eat (Carbs for fuel, etc.) and I know how my body burns calories at the different zones (70% fat @ zone 1, 55% @ zone 2, etc.). However, I'm having the toughest time trying to figure out how many calories I burn during training and if I just add that too my base matabolic rate?


Kevin in MD

Mar 15, 10 14:19

Post #2 of 11 (4157 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

The 405 cx uses heart rate variability calculations from firstbeat and is supposed to be much better than anything else.

Not sure if that is what you have, if you have the 405cx, make sure that if it uses the max heart rate and resting heart rate those are accurate.

I use a suunto that also uses the firstbeat formulas and it seems good. However not that the calories burned includes your basal metabolic rate.

So for example if your basal rate is 100 calories per hour, then the calories burned will include 300 calories of normal metabolic rate.


flipmypancake

Mar 15, 10 14:31

Post #3 of 11 (4145 views)
Re: Garmin 405 Calorie Counter - How Accurate? [Kevin in MD] [In reply to] Quote | Reply

Ahh!! Good point. I never thought about that. So I should just add about 3000 calories which is about 1000 calories an hour which is probably pretty close. So I do 5400 - 500 for 4900 calories I needed to fuel properly. That still seems like soooooooooo much food! However, if I don't eat that much will body start to "store" the food? I mean I would be totally fine putting down 3500 calories and still doin that ride? I still have no idea how much food I should eat a day..............sigh


Kevin in MD

Mar 15, 10 14:45

Post #4 of 11 (4137 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

I think you misplaced a decimal. 2450 calories per day basal rate is about 100 calories per hour, not 1,000.

The number still seems way high, 1,000 calories per hour while riding is pretty darn hard though not impossible. That's averaging something like 250 watts for the entire 3 hours.


flipmypancake

Mar 15, 10 14:51

Post #5 of 11 (4133 views)
Re: Garmin 405 Calorie Counter - How Accurate? [Kevin in MD] [In reply to] Quote | Reply

I wish I could average 250 watts for 3 hours. I'm probably closer to 190 watts with average HR of 133 for the 3 hours yesterday. It was a zone 1 - 2 ride. I think I would be more accurate if I just did 100 calories per 10 minutes which is about 1,800 calories.


Sausagetail

Mar 15, 10 16:16

Post #6 of 11 (4103 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

Way, way off. Divide by 2 and you'll be closer to the actual value. The elevation is probably incorrect, too.


ericlambi

Mar 15, 10 16:56

Post #7 of 11 (4089 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

 
For my last run my 405CX estimated I burned 1175kCal over 19.7mi. That's less than 60 calories per mile and less than 500 calories per hour ( was running 7:16 pace). I hope it isn't that accurate.


Francois

Mar 15, 10 17:33

Post #8 of 11 (4073 views)
Re: Garmin 405 Calorie Counter - How Accurate? [ericlambi] [In reply to] Quote | Reply

While running on the flat, distance in km x weight in kg is usually a relatively good approximation of calorie expenditure (there is also a coefficient based on speed, but it doesn't change the results much). So 60cal per mile, unless you're incredibly light, is highly unlikely.

The cal. from the garmin devices are way off. I have the 705 and it always gives values that are way too high (and are NOT related at all to power output).
-------------------------------------------

http://www.fmcoaching.com / http://elpasotricoaching.wordpress.com / currently accepting new athletes.


stevearnold422

Nov 10, 11 19:49

Post #9 of 11 (2850 views)
Calorie Counter Iphone [In reply to] Quote | Reply

Hi Flower, you should check out http://www.caloriecounteriphone.com/ and if you go up pretty close to the top on the righthand side, you can search for any food. It is very complete and helpful.


Titanflexr

Nov 10, 11 20:03

Post #10 of 11 (2843 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

flipmypancake wrote:
I wish I could average 250 watts for 3 hours. I'm probably closer to 190 watts with average HR of 133 for the 3 hours yesterday. It was a zone 1 - 2 ride. I think I would be more accurate if I just did 100 calories per 10 minutes which is about 1,800 calories.

Considering that Torbjorn set a Kona bike split record on 280W for a bit over 4hrs.; 250 for three hours would be pretty good (esp. at 131 HR). The 190 average might even be a bit high (I don't know how fast you are) given the climbing (and thus the freewheeling on the descents).

HR-based calculators are highly inaccurate for calorie count. Powermeters are much closer. If you have a bike with power (or even an indoor bike with calories/watts) you can get a general feel for how many Kcal/hr. you burn at given perceived effort levels. Note that you will burn ~30% more calories on an indoor bike/hr. due to the lack of stops/coasting (per Chris Carmichael).


__________________________________________________
In theory, there is no difference between theory and practice.


schafjet

Nov 10, 11 20:34

Post #11 of 11 (2837 views)
Re: Garmin 405 Calorie Counter - How Accurate? [flipmypancake] [In reply to] Quote | Reply

I use my power meter. Kilo joules is what I use to figure my calorie burn. I learned from the book "Training and racing with power". I burn about 600 calories an hour + or - depending on effort around 200 watts. The 600 seems pretty consistent on many of my training rides. When I compare it to calories burned on my Garmin settings, calories burned is really high. I stick to kilo joules to determine calorie burn and used it for IMMoo and it worked out great.

   
 
 
 



New Product Intros
Is there a specific event you most closely associate with new product coverage and intros?
Sea Otter
Eurobike
Interbike
Hawaiian Ironman
I'm oblivious