The FastDay Forum

Just read this on exercise and fitness:

"MYTH: YOU BURN THE MOST FAT WHEN WORKING OUT HUNGRY.

FACT: Exercise on an empty tank and your body will tap its stores of fat for energy, right? Nope. A 2011 study in Strength and Conditioning Journal found that the body burns the same amount of fat whether the stomach is full or empty. 'Exercising without eating is not good,' Maryland nutritionist Sue James says. A small snack can help fuel muscle."

I’m disappointed and don’t really believe this. The author of the 8-Hour Diet recommends exercise before opening the eating window and I always try to fit in at least some exercise while fasting and/or prior to eating my first meal of the day. I still think this works really well. Does anyone agree or disagree? And who is Sue James, anyway?????

Hi well what a bummer! I usually do 5/6 mile walk on my fast days x3
Still won't stop it coz it takes my mind of food and when I return I can't face food don't know why probably coz I'm bit knackd. So it's a kind of double whammy, don't see any reason to change Sue

Who cares? I like to do a very brisk walk early in the mornings on an empty stomach. I feel bettter for it, I feel invigorated by it and when I do eat I enjoy my food more so if it's not,scientifically speaking, the best thing to do, well, shucks, too bad! Don't worry, there will be some expert along next week to dispute this latest finding, just do what works for you and ENJOY it!

Ballerina x

Hmmm. I find that if I have had a little something to eat I have more energy, ergo I exercise harder and burn off more. Saying that, I can't exercise for ages after eating a full on meal.

Wow. What a (worthless) study.

It has nothing to do with whether or not you are hungry when you exercise.

It has to do with blood glucose levels. You can have high blood glucose levels and be hungry. If you have high glucose levels and exercise, you will burn little fat.

Fasting reduces glucose levels, and if you exercise the body converts fat to glucose to fuel the exercise. That is why intermittent fasting leads to high fat loss (compared to muscle loss).

Think of runners when they 'carbo load' before a race. They don't eat all of their pasta right before running. They do it the night before. They get up and are 'hungry' (I know), but their blood glucose levels are high enough to fuel them through their race. The process is so much more complicated than having a full or empty stomach, or feeling hungry or not.

I used to jog on an empty stomach too, but after a couple of weeks it started to get too difficult. I could only manage about twenty minutes before feeling drained and exhausted.

So now I will have a little snack like a salad in a slice of brown bread or a few celery sticks about thirty to forty minutes before running. As Ballerina said it is just about personal choice.

[carorees]

The science I've seen says that exercising in the fasted state is more beneficial. I think I've posted some of the studies before...try searching for them.

Here's one: http://www.ncbi.nlm.nih.gov/pubmed/23313101

Vix89 - you illustrate an interesting and common observation.

My guess is that if you would have walked for the same amount of time as you jogged, you would have had no problems with feeling drained and exhausted.

The point is blood glucose levels fuel 'active' exercise, and if you try to run with low glucose levels you will not be successful for very long. The body cannot convert fat to glucose quickly. That is why runners need to carbo load to finish their races as quickly as they can.

But if you walk, the body can keep up and you will not feel bad at all. It is also why walking for reasonable amounts of time with low glucose levels can actually burn more fat than running.

Vix89 - you illustrate an interesting and common observation.

My guess is that if you would have walked for the same amount of time as you jogged, you would have had no problems with feeling drained and exhausted.

The point is blood glucose levels fuel 'active' exercise, and if you try to run with low glucose levels you will not be successful for very long. The body cannot convert fat to glucose quickly. That is why runners need to carbo load to finish their races as quickly as they can.

But if you walk, the body can keep up and you will not feel bad at all. It is also why walking for reasonable amounts of time with low glucose levels can actually burn more fat than running.

Interesting. I looked up Sue James and she advises professional athletes. I wonder if she's referring to or maybe even extrapolating from the more active exercise that a pro athlete is doing.

But I confess, I'm suspicious of anything a nutritionist says.

That study wont be changing my way of exercising 4 x week, 45-60 mins power walking on an empty stomach, as I just feel fantastic for it.

Great advice from everyone, and I can understand eating would be necessary before strenuous excercise.

Every one should do what works best for them, as for myself, I need a small snack before my morning workout otherwise i feel terrible and my workout is not the same. I excercise 6 days a week in the mornings in feast and fast days and A small low carb high fiber muffin of 80 cals with coffee and a bit of almond milk for a total of 90 cals make a huge difference.

This may be a blast from the past...but here in the US there used to be a commercial about the Army doing more before breakfast than most people do all day. (definitely paraphrased as this was way back in the day.) Historically, it is also very common for ranchers and farmers to do much of their chores (labor) before eating breakfast. I think it is a natural thing for humans to do. If you think way back prehistoric man had to hunt or gather the food before they could prepare and eat it. I enjoy a brisk walk in the morning before eating. I honestly think most studies are pointless, biased and continuously conflicting anyway. How does one decide which study to believe as you can find almost always find a pro and an anti stance on any given subject.

Just read this on exercise and fitness:

"MYTH: YOU BURN THE MOST FAT WHEN WORKING OUT HUNGRY.

FACT: Exercise on an empty tank and your body will tap its stores of fat for energy, right? Nope. A 2011 study in Strength and Conditioning Journal found that the body burns the same amount of fat whether the stomach is full or empty. 'Exercising without eating is not good,' Maryland nutritionist Sue James says. A small snack can help fuel muscle."

I’m disappointed and don’t really believe this. The author of the 8-Hour Diet recommends exercise before opening the eating window and I always try to fit in at least some exercise while fasting and/or prior to eating my first meal of the day. I still think this works really well. Does anyone agree or disagree? And who is Sue James, anyway?????

This is a nightmare. I liquid fast and what I love to do is exercise on these days. I am not going to stop though. It feels good, so it must be good. Even my hubby has started running on an empty stomach and he says that he gets further and has more energy!!!

[carorees]

As I already said above, there is plenty of evidence that exercising while fasting is a gooo thing. We have discussed studies on exercise and fasting here: viewtopic.php?f=10&t=4906

Wow. What a (worthless) study.

It has nothing to do with whether or not you are hungry when you exercise.

It has to do with blood glucose levels. You can have high blood glucose levels and be hungry. If you have high glucose levels and exercise, you will burn little fat.

Fasting reduces glucose levels, and if you exercise the body converts fat to glucose to fuel the exercise. That is why intermittent fasting leads to high fat loss (compared to muscle loss).

Think of runners when they 'carbo load' before a race. They don't eat all of their pasta right before running. They do it the night before. They get up and are 'hungry' (I know), but their blood glucose levels are high enough to fuel them through their race. The process is so much more complicated than having a full or empty stomach, or feeling hungry or not.

I don't think it is quite that simple. When we exercise reasonably hard we use circulating glucose for energy. When glucose levels begin to drop we start to use stored glycogen from muscle and liver. This can be converted to glucose really quite quickly. Normally we would store enough glycogen to keep us going for several hours and as soon as we eat carbohydrates we replenish glycogen stores. Only after glycogen is used up will we really start "fat burning" which is actually functioning on a mixture of fuels including glucose which our body synthesizes by a process called gluconeogensis form a variety of substrates.

The entire system is in a state of dynamic equilibrium. It s the balance over time that matters.

Sorry, was that too much detail