Excercising Before or after you eat.

It depends what time I am exercising. I try to run in the morning before I eat, but I do evening circuits classes so obviously I have to eat at some point during the day before them. On those days I don't eat after 4pm. Exercising on a full stomach makes me vom.

<sorry for the long post, just one article from the NY Times regarding working out before breakfast>

Phys Ed: The Benefits of Exercising Before Breakfast
By GRETCHEN REYNOLDS

The holiday season brings many joys and, unfortunately, many countervailing dietary pitfalls. Even the fittest and most disciplined of us can succumb, indulging in more fat and calories than at any other time of the year. The health consequences, if the behavior is unchecked, can be swift and worrying. A recent study by scientists in Australia found that after only three days, an extremely high-fat, high-calorie diet can lead to increased blood sugar and insulin resistance, potentially increasing the risk for Type 2 diabetes. Waistlines also can expand at this time of year, prompting self-recrimination and unrealistic New Year’s resolutions.

But a new study published in The Journal of Physiology suggests a more reliable and far simpler response. Run or bicycle before breakfast. Exercising in the morning, before eating, the study results show, seems to significantly lessen the ill effects of holiday Bacchanalias.


For the study, researchers in Belgium recruited 28 healthy, active young men and began stuffing them with a truly lousy diet, composed of 50 percent fat and 30 percent more calories, overall, than the men had been consuming. Some of the men agreed not to exercise during the experiment. The rest were assigned to one of two exercise groups. The groups’ regimens were identical and exhausting. The men worked out four times a week in the mornings, running and cycling at a strenuous intensity. Two of the sessions lasted 90 minutes, the others, an hour. All of the workouts were supervised, so the energy expenditure of the two groups was identical.

Their early-morning routines, however, were not. One of the groups ate a hefty, carbohydrate-rich breakfast before exercising and continued to ingest carbohydrates, in the form of something like a sports drink, throughout their workouts. The second group worked out without eating first and drank only water during the training. They made up for their abstinence with breakfast later that morning, comparable in calories to the other group’s trencherman portions.

The experiment lasted for six weeks. At the end, the nonexercising group was, to no one’s surprise, super-sized, having packed on an average of more than six pounds. They had also developed insulin resistance — their muscles were no longer responding well to insulin and weren’t pulling sugar (or, more technically, glucose) out of the bloodstream efficiently — and they had begun storing extra fat within and between their muscle cells. Both insulin resistance and fat-marbled muscles are metabolically unhealthy conditions that can be precursors of diabetes.

The men who ate breakfast before exercising gained weight, too, although only about half as much as the control group. Like those sedentary big eaters, however, they had become more insulin-resistant and were storing a greater amount of fat in their muscles.

Only the group that exercised before breakfast gained almost no weight and showed no signs of insulin resistance. They also burned the fat they were taking in more efficiently. “Our current data,” the study’s authors wrote, “indicate that exercise training in the fasted state is more effective than exercise in the carbohydrate-fed state to stimulate glucose tolerance despite a hypercaloric high-fat diet.”

Just how exercising before breakfast blunts the deleterious effects of overindulging is not completely understood, although this study points toward several intriguing explanations. For one, as has been known for some time, exercising in a fasted state (usually possible only before breakfast), coaxes the body to burn a greater percentage of fat for fuel during vigorous exercise, instead of relying primarily on carbohydrates. When you burn fat, you obviously don’t store it in your muscles. In “our study, only the fasted group demonstrated beneficial metabolic adaptations, which eventually may enhance oxidative fatty acid turnover,” said Peter Hespel, Ph.D., a professor in the Research Center for Exercise and Health at Catholic University Leuven in Belgium and senior author of the study.

At the same time, the fasting group showed increased levels of a muscle protein that “is responsible for insulin-stimulated glucose transport in muscle and thus plays a pivotal role in regulation of insulin sensitivity,” Dr Hespel said.

In other words, working out before breakfast directly combated the two most detrimental effects of eating a high-fat, high-calorie diet. It also helped the men avoid gaining weight.

There are caveats, of course. Exercising on an empty stomach is unlikely to improve your performance during that workout. Carbohydrates are easier for working muscles to access and burn for energy than fat, which is why athletes typically eat a high-carbohydrate diet. The researchers also don’t know whether the same benefits will accrue if you exercise at a more leisurely pace and for less time than in this study, although, according to Leonie Heilbronn, Ph.D., a professor at the University of Adelaide in Australia, who has extensively studied the effects of high-fat diets and wrote a commentary about the Belgian study, “I would predict low intensity is better than nothing.”

So, unpleasant as the prospect may be, set your alarm after the next Christmas party to wake you early enough that you can run before sitting down to breakfast. “I would recommend this,” Dr. Heilbronn concluded, “as a way of combating Christmas” and those insidiously delectable cookies.

http://well.blogs.nytimes.com/2010/12/15/phys-ed-the-benefits-of-exercising-before-breakfast/

From what I was told when I was in the military, it really depends on your body type. If you are already a lean person, then you should probably eat a light meal so that your body has some energy store. But if you aren't lean, then you have your energy store already. I tend to carry mine in my hips and thighs .

I tend to not eat before a workout. Especially if its going to be a really hard one. Its easier for me to really press harder if I don't have to worry about hurling afterwards.

if you didn't eat a snack beforehand if you just wake up and work out would you end up eating more anyway?? You would be hungry from your workout plus it would be breakfast time. I eat a small breakfast eg toast an then work out then eat some protien after work out and I have lost 50 pounds

I am looking for a little bit of input on thoughts about working out before or after you eat.. I was watching Good Morning America yesterday and a personal trainer said that she tells her clients to work out before they eat so they can burn stored fat. from watching the biggest loser I thought you needed to fuel your body prior to excercising. I am wonder now how to choose what to do.

I believe this probably depends on what exactly you are doing. Are you doing light exercise, moderate exercise or heavy exercise? As a weight lifter of over 13 years I know my body very well. I have talked with good people, have information from books, DVD's, magazines and the internet. From "my personal experience" doing any heavy exercise you will want "some" energy in order to exercise. If I don't have something to eat at least an hour before I lift I cannot lift as effectively. Afterwards is a MUST to eat to replenish your system. Also when competing in martial arts it was a must to eat something prior; nothing heavy just something light as well through out the tournament.

There are so many things out there with it being one way or the other. I have always found to get all of the information and then through trial and error find what works for YOU. Nobody has YOUR body and they can only provide GUIDELINES.

That seems to coincide with much I said.

One thing I don't agree with, and I used to, is sports drinks. For the MAJORITY of people a sports drink is no great benefit and actually is no better then drinking pop (soda). WATER is the best thing for the majority of people as we can all do away with the excess of sodium we are taking in and these types of drinks are loaded with them.

You should not workout on an empty stomach, you should eat a snack/small meal. Then eat a full meal/protein shake after your workout. The sooner you eat after your workout, the better it is.

If in the AM: I eat afterwards
If in the PM: I've eaten throughout the day


Personally I cannot eat a meal before a workout, because I feel stuffed and cannot perform efficiently (crunches, walking, aerobics, yoga, pilates...).

Good Luck! :-)

I'll have breakfast 7-8am will work out 11am.

This evening i did work out 1hr20min after eating 480cal tea now got funny gut.

I'm with Good Morning America

working out in the morning before eating has been proven to burn 200% more than the same workout after eating.

Eeek. No energy especially after an 8 hour sleep fast? As long as you watch your heart rate. If you work too hard, your body will burn muscle, not fat. Less muscle = slower metabolism which also means less calories burned. You REALLY have to watch your heart rate if you are going to work out on an empty stomach. Make sure to stay in your fat burning zone.