Bonk 2

[Kano]

Great information in the first thread, and now, after sharing with DH, he asked a new question: So when does the FAT he's been saving up for years and years until he started biking start burning?????

Karen in Boise

[Dogmama]

When he lights a fire under his butt & starts riding...?

[brok]

Actually, if I remember my physiology of exercise class correctly - during the first 20 minutes of exercise (aerobic), carbohydrates are the primary energy source. Fat is broken down and becomes the primary source after 20 minutes. The longer you exercise past 20 minutes, themore fat you burn. And on that happy little note I'm off for a 2 hour ride:)

[Dogmama]

If you exercise at a higher rate, e.g., doing intervals, you will burn more calories and that will burn more fat.

[Cassandra_Cain]

I don't remember all the details - or maybe I never knew them - but anyway...

To use fat as a primary source of fuel, I think you have to be going at a rather low pace. Everything I've read suggests that the body much, much prefers carbs as its chosen fuel. Once you bonk....

Either that or the light a fire under your backside theory may apply :D

[velogirl]

So many myths surrounding fat burning, ladies.

Remember, you have dietary fat (ie the fat you eat) and adipose (the fat you store around your middle). We do not use adipose for fuel during exercise.

We are always buring a combination of carb, fat, and protein. While fat is burned in a higher ratio during lower-intensity exercise, you're also burning fewer calories for the duration, so the logic that there is a "fat burning zone" or that you'll melt away your middle by exercising at a lower intensity is a myth. Our bodies are very inefficient using fat or protein as fuel. Carbohydrate/glycogen is the preferred fuel source (and our bodies are very good at utilizing it).

We lose weight/fat by increasing our caloric expenditure (burning more calories through activity) and/or decreasing our caloric intake (eating fewer pints of Ben & Jerry's). It's that simple. It really doesn't matter what intensity exercise you do. Move more and eat less.

If you want to lose fat (or you want your husband to lose fat), you're referring to adipose (the stored fat). The only way to lose that fat (besides liposuction) is to deficit yourself 500-1,000 calories/day. This equals a weight loss of approximately 1-2 pounds a week (3,500 calories = 1 pound). If you deficit yourself more than 1,000 calories/day, you will also lose muscle mass and/or your metabolism will respond by slowing down.

Weight gain was a gradual process -- you don't become overweight overnight. Weight loss is also a gradual process, so be patient.

[Kano]

So, Velogirl, what you're saying is that the answer to his question is "the rest of the day," yes? And then, when he wonders what's the point of the biking, the answer is "to build muscle and what all that will burn the fat," AND "to build strength to cart it all around while we're burning it!"

I was sharing the information about how we need to keep "carbing" while we ride -- run out and we're done for, and then he wanted to know about the fat thing. The idea that "we start burning fat" part way into the session, well, that makes sense to a point -- but then, there would be no such thing as bonk, at least not for a lot of us, because there's just no way I could ride long enough to run out of that fuel!!!

Karen in Boise

[velogirl]

As long as he's burning more calories than he eats, he's chipping away at his subcutaneous fat. Gotta keep him moving, Kano -- that's the secret to weight loss. Calorie restriction + exercise is more effective together than either one alone in losing weight in a healthy fashion.

BTW, one of the greatest mistakes I see new cyclists make, especially those who begin cycling to lose weight, is thinking that riding a bike is a free license to eat anything they want. Because you burn more calories (than if you didn't ride), you're also more hungry. But you need a basic understanding of how many additional calories you're burning. Riding an hour a day doesn't merit increasing your caloric intake by 2,000 calories. I recommend using a tool such as FitDay.com (http://www.fitday.com)to estimate your caloric needs. And if you find you're gaining excessive amounts of weight, you might want to rethink your overall nutrition plan.

Oh, something else I found interesting is that when folks begin an exercise program (such as cycling), they also sleep more (at night) and take more naps. Remember, you burn roughly half as many calories during sleep as you do at rest, so by sleeping more, you reduce your daily caloric need. If you reduce it more than you've increased it by exercising, you actually need to reduce your caloric intake to offset the difference even though you're now exercising.

[Dogmama]

I found this on pub med:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8028502&dopt=Citation

If the sciences makes your eyes glaze over, here is the conculsion:

In conclusion, these results reinforce the notion that for a given level of energy expenditure, vigorous exercise favors negative energy and lipid balance to a greater extent than exercise of low to moderate intensity. Moreover, the metabolic adaptations taking place in the skeletal muscle in response to the HIIT program appear to favor the process of lipid oxidation.

In other words, high intensity training is actually better for fat loss than endurance training. High intensity training spares the muscles - and muscles burn fat at a faster rate than fat. Endurance training tends to use muscle mass - not something you want if you're trying to lose weight.

Also, the notion that a calorie is a calorie is being disproved. Studies are showing and all things being equal (energy expenditure and calorie intake) women who eat a hgher protein diet lose more fat weight and retain more muscle than other types of diets.

Your husband will not build appreciable muscle on the bike. He needs to be in a gym lifting weights to build muscle.

I love my endurance training. I'd much rather ride 3 hours than do anything else. But, these days I keep it at a minimum, 1 - 2 times/week. I concentrate on hills, sprints and short rides at tempo for most of my riding. And I lift weights to retain/build muscle mass. I don't want to be one of those menopausal women who can barely carry groceries to the car.

[thatonegal]

Your husband doesn't lose weight because he hasn't been using up the energy his body has on standby and so doesn't use the energy his body has stored in adipose tissue(fat). A more scientific and biochemical explanation below might help, but no guarantees that I explained it well.


A calorie is a simple measure of energy. Our bodies use ATP for energy so the calories in food are calculated according the how many ATP the food can allow our body to produce. Our bodies digest food and run it through biochemical cycles at the sole purpose of producing the energy rich ATP.
Carbs tend to contain glucose which is the direct ingredient in the glycolysis cycle which has a product that is then directly put into the citric acid cycle to make ATP. So carbs are easy to convert into energy. Fats are made of long chains of molecules which can be easily modified to go into the ATP producing citric acid cycle, but they take the longest to put through. Proteins are broken into small fragments that can be used to produce ATP but because the process to put protein into glycolysis and the citric acid cycle is longer and doesn't produce as much ATP protein is more often broken down to Urea or used to provide protein building blocks to the body.
High protein low carb diets allow the body to use up available glucose(carb) stores in the blood and then when the body looks to make more ATP and the easy to cycle glucose is unavailable it opts for the harder to cycle protein and the longer to cycle fats, but protein doesn't produce as much ATP so the body prefers to use stores of fat in the blood. The trick with high protein diets is that your body can't effectively use all the protein consumed either because of time constraints or there is too much protein in the blood stream so any extra amount of protein in the blood is excreted instead of being stored or used up like a fat or carb would be stored or used.
The steady level of fat in your blood at any time is where your body will first grab fat to produce ATP, and the adipose cells(fat cells) of the body release more fat to keep the blood stream at a constant level. So when you lose weight you have been using up the fat in your bloodstream and the cells that store fat along your stomach, butt, or wherever have been releasing fats so they lose their filling and shrink.
The problem using fat is fat takes time to be released into the blood stream and it takes time to be processed to the proper form. So if you use up most of the carbs and proteins in your blood your body will begin taking protein from your muscles and tissues to make up for the smaller amount in your bloodstream until it can use the fat to produce more ATP.

Everything in the body is about balance.

I am such a nerd. I hope that explanation makes sense.

[Bad JuJu]

And I lift weights to retain/build muscle mass. I don't want to be one of those menopausal women who can barely carry groceries to the car.

Right! And the weight training also strengthens our bones and protects us from osteoporosis--no broken hips! :eek:

[Kano]

Okay -- so, a very simplified answer to DH's question asking if he's not burning the old stored fat while he's riding his bike is "the rest of the time" -- but only if he's not making up for the burning by napping or eating. Which is NOT exactly what to tell him, since he's a bit goofy about eating anyway...

But it's GOOD to eat a bit now and then while riding for a few hours because that keeps him from using muscle tissue as fuel if he runs out of glycogen, yes? Because if he uses the muscles as fuel while riding, then there's no muscle to burn fat the rest of the day, yes?

This has to be simple, and extremely logical for him... (maybe for me too, aside from the logic part) (somehow, I'm getting it: I have holes in my fat padding lately!)

Karen in Boise

[Dogmama]

It is difficult to say without knowing his fitness level and body fat percent. But here is some simple information:

Yes, on a moderate bike ride (he is breathing rather heavily but not out of breath) he should refuel every hour.

Right after exercising, he needs to take in carbs and protein. Low fat milk (preferably skim) with some protein powder and a banana shake would be good. Your muscles are primed to take in protein but they require glucose to do that. Keep the post-exercise meal simple with minimum fat so that it is absorbed quickly.

He needs to lift weights. Men can build muscles and muscles use fat to exist. He would burn more fat at rest by raising is metabolism This is very important.

His diet is extremely important. Why burn 300 calories and then replace them with a 500 calorie ice cream cone?

[velogirl]

Why burn 300 calories and then replace them with a 500 calorie ice cream cone?

Because we can?

:D

Just need to ride off 200 more calories!!!

[Bike Goddess]

What VeloGirl says has been proven by me!:) :) :) :)

During the course of a year I lost about 25lbs just from cycling and eating normally. I wasn't trying to lose weight, but I noticed as the months went by that my clothes were getting bigger on me. (We don't have a scale at home, so I never weigh myself anyway). I had an incident on the bike (touched a wheel and fell) . We went into the emergency clinic to make sure I hadn't broken any ribs. Turned out I was fine- just hurt to breathe. While there, they weighed me. That's when I found out I'd lost all this weight. (I'd been to the Drs. a year before and was last weighed at that time)

Now, two years later, I've gained 4lbs- not sure if that is from eating, time of day, or what. BUT I feel great, my clothes fit, and I'm not too worried. I've also been working out for the past two years so that might account for some of the weight gain.

So, as Lorri says, you can lose weight. It takes discipline, that's all! AND time. It aint going to go away tomorrow because you rode 60 miles today!

[velogirl]

A more scientific and biochemical explanation below might help, but no guarantees that I explained it well.


A calorie is a simple measure of energy. .........

<snip>

Everything in the body is about balance.

I am such a nerd. I hope that explanation makes sense.

Any chance you could share your reference for this explanation?