How Many Calories

sugametal131

Hi, I'm a constant biker and i saw you calories per mile. I just found out that when foods list calories, 1 calorie actaully equal 1000 calories (energy needed to heat 1 gram of water 1 degree celcius). Now i'm worried, are you talking food calories or true caloies?

dhk

Yes, unfortunately, we are talking kcal, or kilo-calories in food. The food labels should say kcal, but they usually leave out the "k", at least here in the US. Isn't the rest of the world now using kilojoules for food energy...believe I've seen that on biscuits from the UK.

Power output can also be expressed in kcal/sec, ie, 1 kilowatt=1 kj/sec=.2388 kcal/sec, or 860 kcal/hr. So, if we know power, and the food energy conversion factor, we should be able to calculate calories burned directly.

According to a velo calculator I found online, 150 watts is good for around 17 mph in level, no wind, smooth road conditions. Guys with an accurate power meter hub may be able to validate this number. Anyway, the 150 watt output level converts to 129 kcal of work on the pedals in an hour.

I've seen factors of 20-25% for the energy efficiency of a trained endurance cyclist. Using this range would mean 516-645 kcal/hr are burned at the 150 watt output level. These values bracket the 600kcal/hr @ 17 mph figure....obviously with lots of room for variation!

Jim's ride

I am 5"11 and 90 kilograms(((FAT)))... Sometimes I ride for 50kms in the hills and the most is 100kms around Adelaide in Australia.
The bike I ride is a $500 Mongoose Mountainbike (Heavy thing it is)
If I remeber correctly my doctor said I should eat 800 calories per day and it's mainly what you eat during the ride.
Example when i stop at a Red traffic Light and I look like I went for a swim I know the calories are vanishing.
I find it very hard to know what amount of calories I eat during the day. The labels on food products look like i need a degree to understand what's in the product.
Cycling is more like a science these days.
I can't wait to follow the Tour Down Under....

2LAP

800 calories amounts to about 2.5 chocolate bars, the minimum that is normaly recomended to people who are losing weight 1200 calories (more for men or larger people).

When calculating how many calories you eat, all you need to know are the number of calories per 100g or 1g and the amount you eat. From that you can calculate how many calories have passed your lips.

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dhk

The "LA Performance Plan" book states that Lance got a scale and weighed everything he ate when he was losing 12 lbs for the '99 TdF. That would certainly be the disciplined approach.

Concerning calorie levels for dieting and training, I've got a 1981 book called "Coaching Young Athletes", which recommends a calorie deficit of not more than 500-1000 calories per day for someone on a training program, a level which would equate to 1 to 2 lbs/week weight loss.

2LAP

The same 500 to 1000 calorie advice is still given and works on the basis that a pound of body fat contains 3500 calories. Of course the calorie defocite can be completed by increasing exercise, reducing food intake or both.

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dhk

Yes, this book proposed that a 500 calorie/day workout, plus 500 calories diet restriction could produce a healthy weigh loss of 2 lbs per week. Seems to be sound advice for long-term results.

Rather than weighing food, I just try to use the serving info on the packaging as a guideline for calories, carbs and protein.

TTguy

During aerobic exercise your body can only handle (about) 300 cals. / hr. REGARDLESS of exercise intensity. So, you should not look to replace all the calories expended during exercise...rather strive to replace glycogen expended as it is used. Sorry for brief 'splaination but this is pretty well documented in authoritative places. Glad to point you in that direction if interested.

dhk

This 300 calories/hour intensity level would translate to something like 75 watts output, or around 13-14 mph. I've heard from a PBP finisher that this speed is the right pace to stay in energy balance for the 1200K.

2LAP

Thats an important consideration when 'refueling on the go'. At high intensities people are sometimes unable to tolerate any water, energy drinks or food at all. This causes problems when riding; as it means you can't take in energy at intense times in races or long climbs, etc. during touring or training.

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