How much does energy weigh?

[Stig-OT-Dump]

OK - I know it is weightless, but what I'm after is how many calories are there in a poound / kilo of fat and what would be the weight of glycogen needed to provide the same amount of calories?

Then, when you use that energy, does the weight leave your body or do metabolytes (sp?) remain in your system?

I'm wondering because I'm contemplating hydration requirements during exercise and wondered if a straight forward weight balance (1kg of weight loss means 1L of re-hydration needed) would work.

Cheers

Stig

 

[ColinJ]

You won't go far wrong if you stick to 1 kg lost = 1 litre of rehydration required. If the principle wasn't true but you stuck to it anyway, you'd gradually turn to water!

When you burn fat, I don't think that it's like burning paper i.e. the bulk of the material being turned into hot gases which are lost, only leaving a small residue behind. There are well-documented exit routes from the human body for solid and liquid waste but I honestly don't think you should bother gathering the material and weighing it!

 

[jimboalee]

Hydrocarbons ( Combustible oils ) - 9 kCals / gramm

Carbohydrates ( Sugars ) - 4 kCals / gramm

Protein - 4 kCals / gramm

Ethanol absolute ( alcohol ) - 7 kCals / gramm.


1 lb bodyfat - 3600 kCals

Water - 0 kCals / gramm - IT WON'T BURN.

 

[jimboalee]

When your muscles use Glycogen, they convert it to H2O and CO2.

You breath the CO2 out and sweat the H2O out.

A simple rule is 1g of CHO gives 1 cm3 water. Its not exact, but a rule of thumb that is close enough.

If I ride gently at a HR that is well in the 'Fat burning' zone, I find I can ride for four hours without need to rehydrate or eat.

I can ride a 100km AUK Populair at average 15 kmh without eating or drinking. The ride is totally aerobic and I am running on Fat much more than recently ingested sugars.

Total kCals for the ride would be about 2500. I will have this much stored from the pevious two days eating.
I will be aiming to lose about 1/2 lb bodyfat on the ride = 1/4% bodyfat.

This would be a good distance Training ride to shed a little fat early season.
Remember - NO extra eating or the ride will be in vain.

 

[ColinJ]

If I ride gently at a HR that is well in the 'Fat burning' zone, I find I can ride for four hours without need to rehydrate or eat.

I wouldn't eat either on a gentle four hour ride. I definitely wouldn't advise not drinking when out on rides, but perhaps you just mean not having to drink extra when you get back?

I can ride a 100km AUK Populair at average 15 kmh without eating or drinking. The ride is totally aerobic and I am running on Fat much more than recently ingested sugars.

I'm not happy with that 'not drinking' comment. If you mean not drinking anything other than water - fair enough, if you can do it. Not drinking at all during 6 hours and 40 minutes of cycling (100 km @ 15 kph) is just plain daft, and potentially dangerous.

Total kCals for the ride would be about 2500. I will have this much stored from the pevious two days eating.

I will be aiming to lose about 1/2 lb bodyfat on the ride = 1/4% bodyfat.

Your figures are similar to mine. I find that I burn about one pound of fat on a '200'. I typically lose 6 or 7 pounds on the day but most of that is due to dehydration.

This would be a good distance Training ride to shed a little fat early season.
Remember - NO extra eating or the ride will be in vain.

I don't think that any 100 km ride is 'in vain', but obviously if you are aiming to maximise weight loss, then any calories you take in have to be subtracted from those you expend.

I wouldn't recommend doing longish rides without taking in any calories. I've had the hunger knock ('bonk') a couple of times in the past and it is such a horrible feeling that I don't risk it now.

 

[jimboalee]

Maybe my metabolism has been set by the day long rides with my school chums where we didn't have a penny to our names and rode to Stratford u A and back ( 40 miles ) without so much as a sip from a forecourt hose.

 

[fossyant]

Any rides over 2 hours, I use Isostar Long Energy. I aim to consume a bottle (700ml) about every 60-90 minutes. 2-3 hour rides will be two bottles...... if longer then it usually involves a refill / stop.

You need to drink....and eat - if at a fat burn pace then you'll get away with more, but not averaging 20 mph over 3-5 hours - you'll be shoving as much in your mouth as possible.....

 

[jimboalee]

Popped out yesterday. 35 mile round trip to deliver a letter.
3 oatie biscuits and a cup of coffee for breakfast.
The ride was just under 3 hours. NO drinks or food.
Got home. Another coffee and then some fried chicken with grated Mozzarella melted over it .

Later in the afternoon, decided to go jogging in the snow.
Morrisons Scottish Game pate with dry toast for tea. Some more of those oatie biscuits with single cream and a drop of brandy.

Out dancing till 11:30.

Note - NO drinks or food on bike ride.

 

[Stig-OT-Dump]

Cheers for the facts and figures there Jimbo, although can't one train one's body to burn off fat at a level of exertion that would let you get home a bit earlier than by going at 15 kmh? You need time to clean those dancing shoes, they won't do it themselves.

With the weather at the moment, I'm happy running >17 miles / 2.5 hrs without drinks or nutrition, but in warmer weather that'd do me right in.

 

[jimboalee]

If my maths are correct, 35 miles is 56 km, and that done in 2 hours 45mins is 20.5 kmh average.
Including a 10 min stop to deliver the letter and say Hello, my riding average was 22 kmh.

That's pretty good on a 33lb Halfords boneshaker with a 73" top.

Cool it

 

[Stig-OT-Dump]

I can ride a 100km AUK Populair at average 15 kmh without eating or drinking. The ride is totally aerobic and I am running on Fat much more than recently ingested sugars.

Total kCals for the ride would be about 2500. I will have this much stored from the pevious two days eating.

100k in 6hrs 40 on that one = dirty shoes at the disco, I reckon.

 

[jimboalee]

Where did you learn maths Stig ??

09:00 start. 6 hrs 40 duration.
Thats twenty to four finish. 1 hour to get home. 20 mins shower & 1 hr to fix supper.
That's 19:00 and the doors open at 20:00

Polish, buff and second polish before departing for boogie.

ps It takes me nearly 15 minutes to tie my bow tie.