Calorie counting

[gbs]

I am trying to develop some rules of thumb to ensure that I do not succumb to the dreaded bonk. So far my experience has been limited to rides of 125k - about 5 hrs in the saddle with ample opportunity to stop/refuel. This year I plan some longer unsupported group rides and do not want to be a drag on the group.

The following conclusions are based upon limited data gathered this year and so may be unreliable and indeed my analysis may be flawed - all comments welcome!

As a 85kg rider at an average speed of say 22.5kph in the Surrey Hills or RP I seem to burn about 520kcals/hour (accrding to my Polar HRM). This result is not out of line with a fellow rider's Garmin derived estimate. So that, for the moment, is my output estimate.

Input values derived from manufacturers' data

• 750ml of SIS GO energy drink 219kcal
• 750ml of Isoenergy drink 228kcal
• 750ml of Hi 5 270kcal
• 1 MULE bar, 65g 233kcal
• 2 trail mix bars, 60g 236kcal

I just do not consume enough to match the output requirement altough I have not yet suffered a bonk. Presumably the starting level of blood sugars etc is filling the gap.

So, I do feel a need an energy plan:
Q1 is the rough conclusion that 2x750ml of energy drink are required each hour to stay in balance?
Q2 how much calorie deficit is sustainable?

Please resist answers that begin "it depends" or counter-questions re the lengh of a piece of string! I do not have a need for precise/race efficient estimates. Rule of thumb response please.

 

[Aperitif]

Morning Geoffrey, I was thinking that you would be loading up on calories prior to a longer ride and therefore have a quantity 'in the bank' non?
I don't purposely eat for riding, but nightimes that have lasted well into the next day (I mean the riding ones - not the Lushketeer ones btw) I would have a plateful of something , invariably covered in cheese...
Particularly on a hot day, fluids are the thing I enjoy. A stop and drink, without the rationing that happens on the bike is bliss. Bit of a puzzler this as I would have thought you had plenty of reserves. I'm also 85kg + a bit...the 'bit' weighing 17kg
Maybe the difference lies in the 'relaxed muscle' after all.

 

[gbs]

Top of the mornin' Apero.

Yes, I do load up the night before but how much is that worth in the bank?

I guess my concern is the unknown; the step up from 120km to an Imperial Century charity team ride in May is new territory for me. Since the team is drawn from my major client's small HO I am not expecting a great deal of experience around me. Indeed I may be a one-eyed king or co-regent for the day. I will plan on the basis that the ride will be unsupported for all practical purposes. Hence my attempt to put some dimension to the feed requirement.

I doubt that will be free to join the HaloJ foodfest this month but hoping for the March ride if it happens in the second half of the month. Even if that gives me a practical answer I would like to understand the theory.

PS understand that the latest advice is that carbo loading should take place 48-72 hrs before the big effort.

 

[Dan B]

An imperial century at 22.5 km/h is about seven hours riding, so your 520kcal estimate would be inside the 35-45 kcals/mile rule of thumb.
Wikipedia suggests that " typical untrained individual on an average diet is able to store about 380 grams of glycogen, or 1500 kcal, in the body, though much of that amount is spread throughout the muscular system and may not be available for any specific type of exercise. ". As you know, you can add to that with carbo loading before the event. You will also have energy available in fat reserves (about 3500 kcals per pound) but that's only really available for low-intensity work. What does your Polar give you as an average heart rate on your rides, and how does it relate to maxhr?

 

[Aperitif]

You'll do a hundred easily Geoffrey! (Obviously I talk full fitness and not recuperation here). Last Sunday, Ian did a bit in Kent, and then we bimbled around London and that saw him polish off 85 miles on two cups of coffee and a bit of breakfast. I did 50 ditto...and no effort. You'll have no problem.
Hopefully someone like fossyant will come along and give the 'proper cyclist' approach, as I am but a butterfly sunning myself on the rim of a glass of carbohydrate, a Camembert muncher, Calvados guzzler - besides, your Regent status will see you through.
What about the others though? You can handle a bicycle, how will they be prepping for the big tour?
When we rode the M25, which was 148 miles +,(and a bit hot) I started with two bottles, a malt loaf rolled as flat as poss. and four Kellogs 'Elevenses'. On the way round we stopped a couple of times for some technicolour drinks from garages (Lucozade is best for me I suspect, because I can read the word 'Energy' on the label) and Kit Kats etc - The Sugar Riders! Then did 18 miles from St Pancras to bed without feeling low or down - exhilarated more like. No gels, but, for anyone feeling a bit low on the Friday Night Rides, I carry 'High 5' - which are good too, + a strip of Pro Plus (+ Aspirin, + Paracetemol etc...) and the gels have helped in the past...no idea of their calorific qualities but they should be sucked in and then take a glug of water. Space savers to - I cart all this stuff in the tri-bag on the top tube.

 

[the snail]

I think you're overdoing the energy drinks. I go for complex carbs (pasta, porridge for breakfast) then have hi-juice/fig rolls to top up during the ride. Complex carbs are better as they are 'slow release', simple carbs (sugary foods) are good for a boost, but too much can cause dehydration or lead to a crash later. I think psychology has a lot to do with it, if you feel you are flagging then eat something you enjoy. Generations of cyclists have managed fine without gels etc, so don't get misled by marketing hype. Don't get too hung up on what your computer tells you, calorie figures are based on rule of thumb formulae, YMMV. There's plenty of nutritional advice available if you google

http://www.bicyclesource.com/body/nutrition/

 

[gbs]

Thanks to every body for the comment, encouragement and data sources.

Dan, Yr data suggest consumption of 630kcal/hr v my estimlate of 520 kcal/hr and wishing to be consertive I will adopt yr figure for my plan. The glycogen bank at 1500 Kcals is v good news; +/- 2.5 hrs of riding.

Heart runs at average of 75% of MHR adopting much maligned 220-age formula. I peak at 105% of MHR without any sense of discomfort so I guess my heart age is somewhat less than chronological age.

Apero, Snail, I am a little wary of gels - I am the kind of rider who always travels with Immodium. I am a great fan of the Tribag for easy access to dried fruit and nuts.


What is the kcal value of a banana?

 

[Aperitif]

You can get your nuts in a tribag when seated on the saddle. Excellent news!

 

[Dan B]

Heart runs at average of 75% of MHR adopting much maligned 220-age formula. I peak at 105% of MHR without any sense of discomfort so I guess my heart age is somewhat less than chronological age.

There are many people for whom 220-age is a poor approximation. I've seen 205 on my HRM, and I haven't been 15 years old any time in the last two decades. Have a look at http://www.brianmac.co.uk/hrm1.htm and figure out where you are in that scheme and it'll probably give you some comfort that you can meet quite a lot of your energy requirement from fat. Assuming that you have any, that is (would you like some of mine?)

My gut(sic) feeling is to side with Aperitif - you're worrying too much. A litre and a half of energy drink per hour would leave me feeling bloated and burping at both ends - I doubt I'd consume that much over the entire ride, in fact. Don;t forget to brush your teeth at the end though if you do.

 

[gbs]

My gut(sic) feeling is to side with Aperitif - you're worrying too much. A litre and a half of energy drink per hour would leave me feeling bloated and burping at both ends - I doubt I'd consume that much over the entire ride, in fact. Don;t forget to brush your teeth at the end though if you do.

Not so much worrying as wishing to ensure that I don't appear as an old fool to the group who are 25-40 years younger. Any way who can worry when Apero chips in like that!

Agreed re vloume - even if one can carry it, it is a considerable hourly volume and if consumed frequent hedgestops would be compulsory.

 

[the snail]

What is the kcal value of a banana?

about 100 - 150, and more electrolytes than a sports drink apparently