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2008-05-25 9:48 PM

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Subject: Calories per hour?

Ok... the thread about drinking sports drinks and gu packs together got me thinking. I've been reading, and according to research I'm supposed to take in 250-300 calories. Currently I've been drinking Accelerade and taking a gu pack every 45 minutes. This comes to about 250 calories an hour.

I typically do ok with the combination of gus and accellerade, but I'm wondering if I'm taking in too many calories. I ran tonight for 1:15 on just water and was just fine, but I'm nervous that if I do only water with gu on long rides/runs (1:30+) I may crash or under-perform.

So my questions are:

1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently.

2. Are you supposed to take in calories throughout the hour, or all at once when you reach 60 minutes? Meaning... Does the requirement start at minute 1, or should you wait until a specific time during your training session? I'm assuming the distance is a big factor with this.

3. What's the optimal number of calories per hour needed? Is heat a factor in this?

4. What are signs that you are under your calorie requirements? How are these different than dehydration signs?

5. If you go with just gu and water, should you consider salt tabs or anything else?

Sorry for the length of this... I was turning this in my head during my run, and figured I'd turn to my BT brothers and sisters.



2008-05-25 10:07 PM
in reply to: #1424108

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Edited by JeepFleeb 2008-05-25 10:07 PM
2008-05-26 12:31 AM
in reply to: #1424108

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Subject: RE: Calories per hour?

Great questions as I've wondered the same.

I know when I'm not  taking in enough calories when I get that "bonk" feeling.  When I stop I get shaky, have waves of nausea and lightheadedness, and get some cramps.  But, that's me.  I've changed many habits since learning through a couple of experiences this year.  I don't want those experiences again, and I'd rather be slightly more calorized than under.

For me (I'm 165lbs, 6'1"), I bring water to my swim sessions that are 30 min +, and gatorade for 45 min +.

Biking 60-75 min I bring a 16oz water and 16oz gatorade and usually use them both.  More than that and I bring a clif bar as well, or two if much longer ride.

Running: I seem to do better with running in that I haven't had the need to bring anything extra along mainly because I don't/can't run longer than an hour. (I am cursed with running).

Heart rate does play a factor as well I've noticed in addition to heat, wind, terrain, etc.  You could always pack a couple more Gu packets or an energy bar for backup if you feel that you're subject to hunger pangs.

2008-05-26 5:44 AM
in reply to: #1424108

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Subject: RE: Calories per hour?
Here is a start.

1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently.
Yes. And this can vary a lot. Someone 150ish burns about 100 cals per mile when running while someone 205ish burns abour 150 cals / mile running.

2. Are you supposed to take in calories throughout the hour, or all at once when you reach 60 minutes? Meaning... Does the requirement start at minute 1, or should you wait until a specific time during your training session? I'm assuming the distance is a big factor with this.
I like to spread my cals out. Of course I'm drinking all mine so its a little easier to do. Eating a gu will give you 100 cals at once.

3. What's the optimal number of calories per hour needed? Is heat a factor in this?
will depend on too many variables. Pace, distance, weight, course and fitness are the major ones. I don't believe heat factors into a cals equation but it does for hydration.


4. What are signs that you are under your calorie requirements? How are these different than dehydration signs?
well you will bonk if you go completely empty

5. If you go with just gu and water, should you consider salt tabs or anything else?
yes

2008-05-26 8:07 AM
in reply to: #1424236

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Subject: RE: Calories per hour?

ohiost90 - 2008-05-26 5:44 AM Here is a start. 1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently. Yes. And this can vary a lot. Someone 150ish burns about 100 cals per mile when running while someone 205ish burns abour 150 cals / mile running. 2. Are you supposed to take in calories throughout the hour, or all at once when you reach 60 minutes? Meaning... Does the requirement start at minute 1, or should you wait until a specific time during your training session? I'm assuming the distance is a big factor with this. I like to spread my cals out. Of course I'm drinking all mine so its a little easier to do. Eating a gu will give you 100 cals at once. 3. What's the optimal number of calories per hour needed? Is heat a factor in this? will depend on too many variables. Pace, distance, weight, course and fitness are the major ones. I don't believe heat factors into a cals equation but it does for hydration. 4. What are signs that you are under your calorie requirements? How are these different than dehydration signs? well you will bonk if you go completely empty 5. If you go with just gu and water, should you consider salt tabs or anything else? yes

Good info... it sounds like it's just a lot of experimenting to see when/how much. I've played around with different combinations, and was hoping there was an easy calculation or something. I know, it's crazy given that this sport has nothing really easy about it.

2008-05-26 8:07 AM
in reply to: #1424108

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Subject: RE: Calories per hour?

Here are a few replies based on long-term marathon experience and a few ultra-distance (50mile) runs, but no triathlon experience (yet!). Warning - this is long. (The questions are complicated!)

1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently.


Yes. A heavier person must do more work to move that weight, though water, on wheels, on feet. Heavier people also have a higher metabolic rate (all other things being equal, which they never are.) Other things matter as well, such as efficiency and base metabolic rate. Your base metabolic rate is a VARIABLE, which is effected both short-term and long-term by many things, including:

  • genetic predisposition
  • gender (male -> higher BMR)
  • age (older -> lower BMR)
  • weight (heavier -> higher BMR)
  • body surface area (tall and thin -> higher BMR)
  • body fat percentage (lower -> higher BMR)
  • recent diet (taking in fewer calories reduces BMR -- the dieters' dilemma)
  • core body temperature (when you are sick or injured and body temp rises, BMR goes up)
  • air temperature (colder -> higher BMR; LONG exposure to heat does the same, but short-term exposure to heat lowers BMR)
  • stress (high stress -> higher BMR)

There are various formulas out there for determining an average BMR, but they tend to be based on body weight, height, % body fat, and the like, and as such will not take into account many of these factors, some of which can have a dramatic short-term effect. Some bathroom scales have a feature that tells you your 'metabolic age' and/or your maintenance calories. I'd take the absolute values it gives you with a grain of salt, but relative changes could be informative for teaching you under what conditions your BMR goes up and down. According to my scale, my metabolic age ranges from 17 to 35, and generally the changes do seem to reflect something that's happening physically with me at the time.


2. Are you supposed to take in calories throughout the hour, or all at once when you reach 60 minutes? Meaning... Does the requirement start at minute 1, or should you wait until a specific time during your training session? I'm assuming the distance is a big factor with this.


For a 60 minute workout, you don't need to take in any calories. Your muscles and liver (and to a far lesser extent, your blood) contain enough carbohydrates (around 1700-1800 calories' worth, mostly in the form of glyocgen) to get you through. Just drink water, then take in some quality carbohydrates after your workout to promote quick healing.

If you're talking about a longer workout (generally more than 60 minutes), then you should start taking in calories. I assume you begin your workout with your liver and muscles more or less full. You definitely don't want to wait until they are 'empty' before you start taking in carbs -- for one thing, muscle carbs and liver carbs are not equal. The muscle carbs primarily deliver energy. The liver carbs primarily regulate blood sugar. So you can get hypoglycemic before you run out of energy. Since the glucose in your blood is responsible for central nervous system maintenance, you will start to get dizzy, stupid, irritable, etc. if this happens. (You should stop exercising at that point...) But you don't really need to start eating at the beginning either -- after all, you're 'full' (by assumption). For example, if you plan to take a swig of sports drink every 10-15 minutes, then take your first swig 10-15 minutes into the workout or race. If you plan to take a gel every 30 minutes, then wait 30 minutes and take one. Piling carbs on top of carbs does not help - it just makes you hyperglycemic (=sick).

There is no clear answer to whether the 'carbo-drip' (small amounts frequently) or the 'carbo-blast' (large amounts infrequently) method is better, to a point. A continuous drip is obviously not convenient. A really big blast is easy, but will probably make you sick to your stomach (which can absorb the carbs only so quickly, and the more intensely you exercise, the longer it takes to absorb them). Experimentation is probably your best bet, starting with the recommendation on the package (of gu, sports drink - not the regular gatorade, please -- or whatever), and adjusting from there. Err on the side of continuous drip at first, and then see whether you can buy some convenience by moving towards the blast method until performance drops.

3. What's the optimal number of calories per hour needed? Is heat a factor in this?


Yes, and yes. Seriously, there is no 'optimal' number, except for you, in your particular current circumstances. That's the bad news. The good news is that you only have to be in the ballpark. Your body is very forgiving and smart. If you get anywhere close, it will make things right for you. A standard formula is 4-6 ounces of a 6-8% carbohydrate drink every 10-15 minutes. You want one with more of the faster-absorbed carbs (more glucose, less fructose). This is a moderate form of the 'drip' method. The moderate form of the 'blast' method is to take the gel every 30 minutes. If you follow the instructions on the packet, you should get around the standard 40-50 grams of carbo per hour.

You'll often see the range 30-60g carbs per hour (around 120-240 calories). That's a pretty big range, and you'll need to experiment a bit to find out what is best for you. You can make some initial adjustments based on how hard you plan to work (all-out climbing effort by a Clydesdale will put one closer to the top of that range, maybe beyond it, while easy spin by a 120-pound climber will put one closer to the bottom, maybe beyond it).

If I'm on a long bike ride, I like to eat something solid. Whether your stomach will take that is up to you, and the conditions on the day. I nibble on a Cliff bar or the equivalent (and drink water or sports drink). Makes me feel very good. I even do this while running sometimes. But on a really hard run, I can't eat -- makes me sick. I just take in sports drink.  But of course that's just an example; you may be completely different, and there's only one way to find out...

By the way, many gels and sports bars contain all sorts of fancy amino acids etc.. There is no solid evidence that these things do anything during exercise except raise the price of gels and sports bars. But some people swear by it. If it works for you go for it. (On the other hand, they are very important after exercise, to promote healing and growth of muscle tissue.)

Heat is a factor, but much more for fluid and electrolytes than for calories.

4. What are signs that you are under your calorie requirements? How are these different than dehydration signs?


Bonking, of course. If you get hypoglycemic you may experience: palpitations, shaking or shivering, nervousness, uncontrollable sweating, unusual warmth, dizziness, dilated pupils, numbness. Of course, these symptoms can be brought on by other things -- some of them by dehydration. So please don't get hypoglycemic.

When you are bonking or dehydrating, you'll know something is wrong. And it's really too late then -- from a health perspective, you should just stop. A better approach (than worrying about telling whether you are dehydrated or bonking) is to find out what it feels like when you are optimally powered. Experiment. When you get it right, you'll know what it feels like to get it right, and then you'll know what it feels like to get it wrong (it isn't right!), and you can adjust on the fly.

5. If you go with just gu and water, should you consider salt tabs or anything else?

I haven't read the gu packet lately, but at one time, at least, they didn't have enough electrolytes, so yes, you'd need to take something with them. Some gels do have electrolytes. (I believe that PowerBar gel claims to have them in the right amounts.  But frankly I don't see how this is possible, since conditions can affect calorie needs differently from elecrolyte needs.  Heat, for example, will make you sweat a lot more, but will not affect your carloie needs nearly as much.)

Sorry for the length of this... I was turning this in my head during my run, and figured I'd turn to my BT brothers and sisters.

Ditto. I guess you reap what you sow...




Edited by mdickson68 2008-05-26 8:24 AM


2008-05-26 8:24 AM
in reply to: #1424324

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Subject: RE: Calories per hour?

Thanks for the detailed response mdickson68... I am a big guy (5'11" 195lbs) so I was curious how much that played into the equation. Some say they can go hours on just water and gu, and I'm wondering if these are the lucky guys who are 160lbs. It's my third tri season and I'm trying to refine my nutrition, so that my success/failure is not tied to that.

Now that the Texas heat is in full swing, I'm taking in a lot more fluids which is a major part of my calorie intake. So I think I'll try without accellerade (and increase gu intake) to see if that has an impact either way. I really don't want to take in excess calories if I can figure it out. 

 

 

2008-05-26 9:59 AM
in reply to: #1424108

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Subject: RE: Calories per hour?

As with most aspects of triathlon training, opinons and philosophies are a varied as our bodies and goals.  I biked 90 miles Saturday on three bottles of water - no fuel at all.  At 40 miles out my average speed was 18.12 mph.  At 90 miles my average had dropped to 17.31 mph so my performance suffered nominally on the second half of my ride.

Yesterday I ran 12 miles with no fuel and no water.  My pace slowed by about 30 seconds per mile on the back half of my run.

I am 245 lbs so I carry a lot of fuel with me.  My theory is that I need to train my body to use its own fat stores and, since I'm training for an IM, I need to be able to perform with a calorie deficit.

Just to caveat my radical methods, I never lose more than 3% of body weight while training.  I've been doing triathlons for over 10 years and I know my body and the limits of my body.  One of the reasons I love triathons is because it allows me to test the limits of my body.

~Mike 

2008-05-26 11:41 AM
in reply to: #1424108

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Subject: RE: Calories per hour?
I think a long workout on just water is fine for almost anyone (or rather, anyone who can do the long workout in any case). I've done many many runs that way, and for many years I raced
half marathons on just water. People who are thin and have high metabolism should probably not just go out and try it cold though (i.e., without some knowledge of how their body will react).  And if you have a good training eason to do it, why not?  You are unlikely to be performing at maximum capacity, but of course we train for all sorts of reasons, not just to be fast on that day.


Edited by mdickson68 2008-05-26 11:44 AM
2008-05-26 3:52 PM
in reply to: #1424236

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Subject: RE: Calories per hour?

ohiost90 - 2008-05-25 12:44 PM Here is a start. 1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently. Yes. And this can vary a lot. Someone 150ish burns about 100 cals per mile when running while someone 205ish burns abour 150 cals / mile running. 

Much easier: your weight in kg X distance in km.

If you do it with cal/hr it will depends on the speed and it will be different, depending on the weight. While going with the distance everything is easier in running calculations. 

2008-05-26 7:00 PM
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Subject: RE: Calories per hour?
Plissken74 - 2008-05-26 4:52 PM

ohiost90 - 2008-05-25 12:44 PM Here is a start. 1. Does weight factor into how many calories you need per hour? We all have different takes on this, but I'm curious if our interpretations are hindered because we all weigh differently. Yes. And this can vary a lot. Someone 150ish burns about 100 cals per mile when running while someone 205ish burns about 150 cals / mile running. 

Much easier: your weight in kg X distance in km.

If you do it with cal/hr it will depends on the speed and it will be different, depending on the weight. While going with the distance everything is easier in running calculations. 


Hence the reason I stated my cals by mile, not time.

and kgs / kms might be easier for the entire world but for us americans not on the metric standard it can be conversion nightmare


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