Exercise! - Working out before breakfast--pros/cons?

03-10-2004, 10:44 AM
I find that I am most likely to fit working out into my day if I do it first thing in the morning. However, once I have gotten up (7:30), hydrated, eaten breakfast (usually 200-300 calories of protein and complex carbs, like plain nonfat yogurt, Fiber 1, & blueberries), and given breakfast 45(ish) minutes to settle, it's no longer "first thing" and, despite the fact that I'm a graduate student and I set my own schedule, some crisis has likely popped up with work or home that I need to deal with, and then I've lost my momentum.

I know people who work out before breakfast, but I've never tried this. I usually wake up hungry, but of course I know from experience that cardio usually suppresses hunger (until you're done anyway). Is this a good plan, though? Will you burn more/less/different calories if you exercise on a completely empty stomach? Is there a danger of feeling faint (if I'm not normally hypoglycemic)? Women's fitness magazines will tell you that you need food to "fuel" a workout, but I know all too well that I have plenty of stored fuel around my tummy and thighs!

Anyway, if people have had good or bad experiences with working out before breakfast.....



03-10-2004, 03:36 PM
Iíve always worked out very early in the morning (5 Ė 6 a.m.) before eating breakfast. The main reason Iíve done this is that if I eat and then work out, I ďfeelĒ that food and sometimes even feel like Iíll regurgitate it from all the movement Iím doing (I donít mean to be gross, but thatís what it feels like). I donít have the time to eat & then wait until my food settles because I have to walk my dogs, get ready for work, etc.

Anyway, my experience? Iíve never had a problem. People have issued dire warnings to me about getting ďfaintĒ and have recommended that I drink a glass of juice or eat a banana, etc. , before working out. However, I just canít see eating something or drinking juice before working out if Iíve never had a problem on an empty stomach. I do drink plenty of water both before and during my workout (about 24 oz. total).

Although the above-stated reason is the primary one that I donít eat before working out in the a.m., another reason is that I donít want to consume those extra calories. Letís face it, Iím going to be working out and will probably burn 200-350 calories, so why would I want to make 100 or so of those calories null and void by eating before working out? Again, thatís not the primary reason, itís just a secondary reason. I eat when Iím hungry & if I really wanted to eat at 5:30 in the a.m., I would, but I donít, so why should I force myself? I much prefer getting my workout over with, getting dressed & ready for work, and then sitting down to relax a few minutes with a good breakfast and a hot cup of coffee. At that point of my morning, I feel as if I can really enjoy what Iím eating because I donít have the workout, dog walk, shower, etc. hanging over my head.

In short, Iíve never had a problem not eating before my morning workout, so Iíd advise you to try it. If you do feel dizzy or anything like that, then you may be one of those people who does need to eat a little something before working out.

03-14-2004, 09:46 PM
I exercise in the morning before I eat and have not had a problem. I do keep water handy because I get thirsty! DM

03-15-2004, 03:21 PM
Apart from the reasons already stated - feeling dizzy or faint - there is one other major physiological reaosn and that is that working in a carb depleted state means that your body is forced to work on it secondary fuel source - lean tissue!

This quite literally means that you are using your muscles as food! This is not only unhealthy it is inefficient and actually slows down your possible weight loss and increase in fitness levels.

This is the reason why I advise my clients to have something to eat before they exercise. A glass of watered down orange juice, a full fruit smoothie, a banana, anything that gives your body a handful of carbs to work on.

I am sorry to disagree with vmelo but the 100 or so kcals burned need to be fat not lean tissue so the 100 kcals consumed ensure the correct, efficient and beneficial burning of the right body fuel!

03-16-2004, 09:45 AM
Stef -

I thought that the body stored quite a bit of carbs in the body to make lean tissue burning an emergency state only...? In the liver, in the form of glycogen? Maybe I have to read up on this, but I thought when on, say, Atkins, it takes 2-3 days of super strict low-carb eating to push your body to the point where you'd go into ketosis. I figured from this that exercising in the morning on an empty stomach would be ok, since I'd eat only an hour later.

But, maybe this explains why I have no energy exercising on an empty stomach at 6 am! ;)

03-16-2004, 12:31 PM
Hi Sarah. Yep that Atkins certainly gets around. Ketosis is different from carb depletion.

It occurs after a number of days and means your body has burned a large amount of fat in response to the fact that it didn't have sufficient glucose available for energy needs. Under everyday conditions, the carbohydrates you eat are converted to glucose, which is the body's primary source of energy. Whenever your intake of carbohydrates is limited to a certain range, for a long enough period of time, you'll reach a point where your body draws on its alternate energy system, fat stores, for fuel.

Being carb depleted after a night's sleep means that your body does not have enough stored glycogen to support the work you are trying to do BUT is not deprived enough to switch to using fat STORES for fuel. So your body burns the next best/easiest thing - lean tissue, muscle, just the opposite of what you actually want to do!

Obviously there is a lot more physiology and nasty science to all of this, and even the two statements above are open to contradiction (I would willingly contradict them both in another thread and still be correct) but the fact remains that your body needs carbs to burn fat. Only in extremis can your body switch to a non carb based fat burning mode. This is probably one of the 3 basic flaws in the low carb weight loss explanation!

And even if you don't go for the scientific explanation a lot of people do feel drained and lifeless or dizzy and sick if they exercise on an empty stomach. Some people who feel no side effects say they feel better and more lively when they try to eat first. Others honestly seem to work better without!

03-17-2004, 01:42 PM
Hi, Stef. I certainly don't mind you disagreeing with me. I don't know your credentials, but you sound like you know what you're talking about! :) Personally, I just haven't found any negatives to not eating before working out. When I'm on program (i.e., 1500 calories a day, working out, etc.), I lose a pound a week, which is what I expect to lose, so I don't think exercising on an empty stomach has slowed down my weight loss (going off program has, though - LOL). Additionally, I don't feel dizzy or faint or anything at all when I work out on an empty stomach. Since I don't have time in the morning to let my food settle, eating or drinking juice and then exercising seems to make me feel as if I'm going to give up the contents of my stomach (sorry!). Also, I hate shoving down food when I'm not sitting down and enjoying it. But, that's just me. I'm sure that you are correct in your explanation; everybody's got to do what makes them feel best.

03-18-2004, 03:27 PM
Hi there,
Gotta agree with Steph on this one. You may lose more weight working out on an empty stomach, but it may not be fat. You will eventually lose the fat that way too, but your overall bf% will be higher and lean mass lower if you are burning off lean tissue. That being said, I have often done short high intensity interval cardio before eating with no loss of lean tissue mass. Short is the key- 20-30 minutes. The few times I've tried to do weight workouts, I can't lift for more than about 10 minutes, get dizzy, klutzy and dangerous. Also cannot lift nearly the weights that I can in a "fueled" state. Since I lift to build and maintain muscle (which looks better than and helps burn fat) this is important to me.

If you are not low carbing, your liver stores enough glycogen for about a 45-60 minute workout under any conditions. After that is depleted, your body uses lean tissue (catabolic pathway) before it uses fat (lipogenesis) as a fuel source. That is why body builders try to keep their workouts to an hour or less, and why marathon runners look like beef jerky.

My credentials are that I'm a certified personal trainer, and currently working on a certification in performance nutrition.


03-18-2004, 03:28 PM
Hi vmelo,

I'm with you on that one. Personally I hate eating before a work out, I too have problems keeping it down, but I struggle to eat something, cos I was taught I should.

If you don't get any problems and you are on taget then hey ho - keep on keeping on, I would.

I just can't advise other people to exercise empty - it's my job. I am a Healthy Living Worker with an advanced degree in Health and Physical Activity so I am a group fitness instructor, stop smoking facilitator and a weight management counsellor and lots of other things all rolled up in one.

I can't begin to tell you how many big and small trianing sessions I go on in a year!!!

Good luck staying "on programme"! I'm feeling smug at the minute cos I too am managing a steady 1lb per week loss. And I must admit I rarely get to breakfast within 2 hours of waking up!!

Still, it's a "Do as I say not as I do" world!!!!

03-18-2004, 04:03 PM
"a lot of people do feel drained and lifeless or dizzy and sick if they exercise on an empty stomach" That's me. And I sometimes get a throbbing headache as well. I might just have half a slice of toast with a smear of peanut butter, or a few sips of a smoothie : eaten 30 minutes before I exercise, that's enough to keep me going.

03-18-2004, 05:22 PM
Here's my question. Let's say some morning I can actually get up in time for a nice hour-long workout. I can tell you I am so not going to make it out of bed in time to eat something and wait 1/2 hour to work out. Can I just eat and start right in on my workout if I promise not to puke or do I need to wait for some of that to digest?

03-18-2004, 05:42 PM
It takes 20 minutes for the nutrients to get from your mouth to your blood stream. You should have at least 20 minutes of stored glycogen. So if you promise not to puke, go right ahead :lol: If you have a protein shake, the nutrients hit the blood stream within 10 minutes.

In the end, we are all an experiment of 1, and you have to do what works for YOU and do what you will do consistently.


03-18-2004, 09:11 PM
Hi, Meliris. That's so interesting what you said about bf% being higher if my body burns lean muscle mass. I think you're on to something. Even when I've been the weight I want to be, I always seem to have a high body fat percentage. I blamed it on genetics and my lackluster lifting routine, but now I'm wondering if working out on an empty stomach might be a contributer.

So, here's my question (sorry to highjack your thread, BellyDancer!) to Stef & Meliris or anyone else who wants to chime in: what would you suggest someone like me --who works out in the a.m. & wouldn't have time for my food to settle-- eat/drink before my workout? I haven't tried eating/drinking anything before working out in years after having a negative reaction to it (as explained in previous posts). I guess the key would be something that would digest quickly.

03-18-2004, 10:01 PM
vmelo- If you really can't workout with anything in your stomach, then the next best thing IMO is to get lots of good lean protein and a fast acting carb into your system within 15 minutes after lifting. You need the carb to help transport protein for muscle repair. The only other thing I can suggest is my standard early morning breakfast when I have to be at the gym super early for an earlybird client: 1/2 cup dry oatmeal nuked with 1 cup water for about 2 minutes, then stir in 1 scoop of protein powder. It's fast, tastes good and is warm, but if you can't tolerate anything in your stomach, it's not going to be much help. How about a protein/fruit shake? You can drink it on the way to the gym on lifting days.

03-19-2004, 01:56 PM
Can I ask a question also. I am just starting to plan my lifestyle change and since I have a underactive thyroid I have to take my meds and weight an hour before I can eat. I was going to do this. Take my meds, do cardio only, eat go to work.......day goes on......do weights in the evening after dinner with hubby. is that OK??? Also if I eat dinner then do weights, what should I have after I work out but don't want a meal is it protien or carbs I am looking at putting in my system.

Sorry to ask stupid questions but I am finding this all confusing and interesting at the same time. Could someone just invent a pill that has all the stuff your body needs and that can be released at the right times??? Wouldn't that make life easier....lol

Thanks for all the expert advise I have read here

03-19-2004, 01:56 PM
Sorry did quick response and now I am not subscribed.... :lol:

03-19-2004, 04:33 PM
Hockeychick- If you are lifting after dinner, you still need to get protein and carbs into your system after lifting. If you don't, you have nothing to repair the broken down muscle tissue. At the very least, have a shake with a scoop of protein powder and some fruit. The fruit is a fast acting carb because of the fructose.

03-19-2004, 06:32 PM
Hockeychic, I have that pill... just send your check for $19.99 to this address.....

Seriously, Meliris has some good suggestions. I am not American so I can't comment on all of those protein shakes etc, we just don't do them so much over here. But from a nutrition point of view a glass of watered down fresh OJ would be a good thing to start with.

Watering it down enables it to be transported across the gut lining and into the bloodstream more quickly, and makes it less acidic and therefore less likely to upset your digestive/urinary systems.

I just can't do chewing if I have been awake less than 2 hours, so I drink my first breakfast, workout then eat a second breakfast. This adds 150kcals to my daily total and ensures I get at least 3 of my 5+ fruit and veg for the day!

Breakfast 1: A fruit only smoothie. Blend a handful of frozen fruits with apple juice and drink!

Breakfast 2: Branflakes and milk, dried fruit and nuts. OR wholemeal bread and jam (preserve?) and coffee

Breakfast 1 only has to serve for the workout, number 2 has to sustain me until lunch, hence the slower less refined carbs.

As for your meds, I am pretty sure that you can drink juice at the same time, it is just solid food type food that you can't - this is to allow the meds to hit your bloodstream effectively. Check it with your specialist, ask if watered down juice and some exercise would slow down or impair your med take up!

03-19-2004, 10:20 PM
Thanks for that info., Meliris & Stef. I love oatmeal, Meliris, so I may try what you suggested. I may also try that watered down OJ thing Stef suggested. If the OJ is watered down, I may be able to tolerate it. Thanks, again!

Jennifer 3FC
03-21-2004, 04:53 PM
Meliris, I have a question. You said

"After that is depleted, your body uses lean tissue (catabolic pathway) before it uses fat (lipogenesis) as a fuel source. "

Ok, if I go through my glycogen stores, I will burn protein before fat? I had learned years ago that you have to work out for 30 minutes before you get to 'fat burning'.
I thought the order was carbs, fat, protein in the exercise phase. If not, and the 'fat burning' was referring to calories burned, is a 60 minute cardio workout necessary? Would two 30-minute sessions at different times in the day do the same thing?

Did my question make any sense?

03-21-2004, 06:59 PM
[QUOTE=Jennifer 3FC]
Ok, if I go through my glycogen stores, I will burn protein before fat? I had learned years ago that you have to work out for 30 minutes before you get to 'fat burning'.
I thought the order was carbs, fat, protein in the exercise phase. If not, and the 'fat burning' was referring to calories burned, is a 60 minute cardio workout necessary? Would two 30-minute sessions at different times in the day do the same thing?


If you go through your glycogen stores, you'll burn lean tissue before fat. The fat is utilized last, unfortunately. A 60 minute cardio session at a moderate level (what most cardio machines call "fat burning mode") is the most that I'd recommend. You can accomplish the same or better results by increasing the intensity and doing intervals of high and lower intensity (walk-jog-walk-jog) and be done in 30 minutes. If you want to do continuous moderate cardio, 2 sessions are probably better if you have the time for all that. The fat eventually gets burned, but it's after the exercise session is over and your body is rebuilding itself, as long as you are in a caloric deficit.

Make sense?


Jennifer 3FC
03-21-2004, 07:50 PM
Ok, I think that makes sense. So, more than 30 minutes is not specifically required to burn fat. I've heard the phrase 'you're not burning fat until after the first 30 minutes' -that would be incorrect, right?

One 30 minute session that is higher intensity can burn the same amount of fat as a lower intensity, longer session? As long as I am in a calorie deficit.

Is that what you just said? :lol:

03-21-2004, 08:01 PM
Jennifer, the designation 'fat burning' is misleading.

In the context of aerobic exercise, scientists usually measure intensity using VO2max (a way of measuring your aerobic fitness) or heart rate. The harder you train, the higher your heart rate. You're also said to be working at a greater percentage of your VO2max.

When you walk, for example, you're exercising at around 40% of your VO2max. Turn that walk into a jog, and both your heart rate and the percentage of your VO2max that you're exercising at will rise.

Your body uses different proportions of its two main sources of fuel (carbohydrate and fat) depending on how hard it is working. The concept on which the fat burning zone is based is the idea that your body derives a higher proportion of its energy from carbohydrate the harder you train ó which is true.

For every 10 calories you burn during exercise at a high intensity (85% VO2max), up to 3 of those calories will come from fat.

For every 10 calories you burn during exercise at a moderate intensity (65% VO2max), up to 6 of those calories will come from fat.

So how did the fat burning zone myth thing get started. Well, yYour body is always "burning" a mixture of carbohydrates and fat for fuel. This mixture tends to contain a little more fat during lower intensity exercise. Somebody took this to mean that a lower intensity workout was best for losing weight.. not so!

1. It all comes from the same "pot". It doesn't matter if you're burning a little more fat or a little more carbohydrate at any particular time in your fuel mix. It all comes from the same calorie pool. The bottom line is, how many calories are you burning.

2. Moderate intensity exercise actually burns more calories in a given time period. For example, you may burn 200 calories during a 30 minute low intensity exercise session and 300 calories during a 30 minute moderate intensity exercise session. Bottom line.. burning more calories is better for weight loss.

3. Moderate intensity exercise increases your basal metabolic rate (BMR) more than lower intensity exercise. This means that you'll burn more calories 24 hours-a-day.

4. Here's the one I like! Moderate intensity exercise gives you a better "high"! You know, the "exercise high" you get when your body releases endorphins and adrenaline. This can really elevate your mood and is great for people who are depressed.

So? Well work out your training zone using the Karvonen principle - you do know it, honest! It's the heart rate one where you subtract your age from the magic number 220 to get your theoretical maximal heart rate (MHR). Then you work out 60% and 80% of your MHR. If you are just starting your exercise program, you should be at the lower end of the range. As you become more conditioned, you can move up in the range.

This will help you to get the most benefit from the exercise you do, cos you'll find it easy to start with giving you a chance to learn how to enjoy it. Then as you get more able you can push it up to get the 'high' in number 4!

The problem is that the science is REALLY scary and varies fromperson to person! In order to get the 'real dope' you need to read the execise physiology bible and that is a) very expensive and b) passes way over the heads of most students who have to read it to pass their sport and exercise exams!

But please be assured I passed those exams with flying colours and use this info on a daily basis. I myth bust for a living. In fact I might change my job title to "Grand Vizier and Exercise Myth Buster"

Oh! To answer your question about splitting sessions - don't panic about it. Evidence suggests that for the less than elite athlete as long as you accumulate the exercise minutes you get the benefit. Although there is a definite benefit to longer sessions this benefit is not big enough to force your body through a long and painful and injury inducing session instead of 2 more comfortable shorter ones! The shorter sessions make it more likely that you will enjoy it and be pain free and therefore, more likely to continue - win win in my book!

Jennifer 3FC
03-23-2004, 12:17 AM
Thanks to both of you, you've been a big help!!

03-23-2004, 12:50 AM
I am part of the group that exercises in the afternoon between meals 4 and 5 (I eat 5-6 times a day) I always have and always will exercise in the afternoon/evening because that is my preference.

I think that it's important to just do it and of secondary importance is what time of day that you do it.

Hockeychic - working out in the afternoon is ok!


03-25-2004, 04:39 PM
Ok, so I'm confused now. Do I need to eat something before EVERY workout? Or just in the morning b/c I haven't had anything to eat in about 8-10 hours? I usually do Pilates first thing in the morning and then I eat breakfast - should I switch this? I thought that I was doing more good b/c I was boosting my metabolism and heart rate before eating - meaning that the calories would burn quicker. I'm sure that I'm wrong as I have absolutely zero credentials :)

03-26-2004, 07:27 AM
Hi Emily,

No credentials doesn't mean you are wrong. Crikey, I have a bag load of them for my job and I often know absolutely nothing at all!

Physiologically you should eat something before you do your Pilates, although many people don't and don't seem to suffer for it in any way whatsoever. This is because, as you rightly said, you haven't eaten for 8 - 10 hours and it is likely that your body is in a carb depleted state.

Now I know I will always bump heads here because the HUGE amount of exercise information that is out there comes from all sorts of sources. BUT I will say, until someone I respect tells me different based on scientific trials, you CANNOT burn fat in a carb depleted state! You will only burn off the bits of your body that don't disturb you. You will still burn calories but not as many as you could have and not in as efficient and healthy a manner as you would have if you had eaten a litle first.

The good news is that a large glass of watered down orange juice is enough!

As for afternoon exercises, if you eat regular meals then you probably won't need to eat specifically for yor exercise. The chances are that you will have eaten within 2 hours of your session anyway.

Of course you could just ignore all the conflicting advice you are getting and do what feels comfortable for you! As long as you have a sensible balanced diet and aren't trying to run a marathon a day then you should be doing just fine as you are!

Good luck!

03-31-2004, 01:03 PM
Thank you Stef! Your advice was pretty much the same as my aerobics instructor (I was so intrigued by this thread that I asked her before class that day). She went on and on about something in the liver and all sorts of biological functions that a pre-law major doesn't really care about - then she said "but you'd be fine with just a glass of juice". SCORE! I can certainly do that!

05-22-2006, 01:16 PM
Hey Mel, you seem to know your stuff so here's my question.
Do I really need to go out and get a bunch of protein shakes in the morning if I only have 15-20 minutes to digest? Or will a glass of orange juice or an apple be enough?


05-22-2006, 01:29 PM
sorry one more question. should I change what I eat for a weight lifting workout and a cardio workout?

05-22-2006, 04:21 PM
An article I was just reading (it was about the most important meal of the day being your after-workout meal) said that a weight lifting workout requires more protein, and a cardio workout requires more carbs.