some excerpts:
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.
I really don’t like training before breakfast, no matter what the workout. Even before I go swimming I have a bowl of cereal. But in the build up to my A race this year I normally trained before breakfast, which I believe was a big contributing factor to getting down to race weight. Not something I like to do all year round though.
I like training before breakfast. In fact, now that I came home from my swim at the Y to make sure my daughter and wife aren’t sleeping through their alarms (an all too often occurence), I’m heading back for my run, and then after that I’ll have breakfast. Of course, I do drink coffee when I first wake up.
some of us reserve our caffeine intake for race end sections and night driving. i always recall the advice from a grizzled old ultramarathon cyclist i received once: “success at 200 miles and above is 50% training, 25% luck with the weather and 25% the judicious application of caffeine”. with such power to hand, why would you want to dilute it by using it every morning?
x2. Just back off the coffee about 4-5 days before your long “A” race. Then start the caffeine about mile 10-18 of the run leg. That’s my approach, though I’m timed by sun dial, and my words have forked no truths.
I have coffee and a cliff bar pre workout. I could get away without eating for shorter workouts, but I think I would probably overeat later. Better to eat earlier so you have the CHO to burn, I think.
I could never do the coffee pre-workout. Especially on weekdays when my alarm goes off minutes before I need to be out the door headed for the pool. After my morning workout though…you better believe it.
Interesting, thx for posting. I never much liked eating before morning workouts, although occasionally, during a high volume build period for example, I might chug a Boost before a longer morning session. Now that I have a dog, I find that I have no desire to eat even after my morning run with her. I find my appetite is suppressed at least another hour or two, I often eat breakfast at my desk at work at ~9am (and I’m up by 6 or earlier).
In my experience, the benefits of training before breakfast have to be weighed with the possibility of increased recovery time.
Their routines sound like they were around 5 hours per week (skimmed the article). This is only 20-50% of what alot of us do (hence an issue like longer recovery would go unnoticed during the study).
As a side note, the only VO2 max test I ever did was done somewhat semi-fasting, as I hadn’t eaten in maybe 4-5 hours and was pretty hungry. I drank a little gatorade prior, but would not have trained in that state. I reached failure at an RER of 1.08, which is quite low for that intensity and may indicate slightly less carbohydrate burn.
I have also seen some other data that suggest a low RER for a given intensity with less cho available. What this means to all us and our training is probably yet to be determined- after all, there are other ways to lose weight, and if this method comes with a reduction in training efficacy, then it may not be appropriate.
My morning sessions are no different than race mornings. ~100 calories (Hammer Gel or Banana) and a little water within 10 minutes of starting and that is it. Breakfast is later. This works very well for me.
That was a pretty interesting read! I think over the winter break I’m gonna give that a try. I almost always eat before my morning workouts, so I’m gonna do a little self experiment and try doing workouts before I eat and see what kind of results I get. As an Health Sciences major, perhaps I can get some research creds with my professors.
Interesting study. I’d like to see more scientific scrutiny before I start doing (or TRYING to do!) 21-mile runs on water alone with no prior breakfast, though. Although I’m not trying to lose weight, the supposed improvement in fat-burning efficiency would certainly be an important benefit for marathon training. In my part of the country, it would also be a major benefit to be able to start a long run in the summertime earlier, without have to wait until after breakfast has digested.
