I have two related question about when one should eat relative to working out.
First, I’ve know that you should eat a small snack, like half a banana, before working out. I generally don’t do this, since I often go to the gym before work and I don’t remember to grab something to eat before I stumble out of the house at 6 a.m. Does anyone have suggestions for pre-workout munchies?
Secondly, and more importantly, how long should one wait to eat after a workout? A friend told me that you should wait an hour so that your body is burning the fat it has already stored, rather than your newly ingested meal. However, a trainer at my gym said that you should eat about 15 minutes (and no more than an hour) after a workout. He said that your body burns muscle before fat and that if you don’t eat right away, you’ll mostly burn muscle. I’m more inclined to believe the trainer, but we all know that fitness professionals can be wrong. (Bouncing while stretching, anyone?)
I wouldn’t recommend anything other then a very light snack before working out. A piece of fruit, toast or even a “power bar” should do it. Remember to drink a lot of water though.
I have always heard that you should eat as soon after a work out as you feel like it. The reason I have heard is that your metabolism is higher right after a work out and you will burn more calories out of the meal. I am looking for a site for that.
Your trainer is full of crap in at least one respect. You don’t burn muscle, you use carbohydrates and fats, not muscle fibers.
As far as my own personal experience goes, how much I work out and how much I eat seems to be the major factors in weight loss and condition. When I eat has never seemed to matter. I dropped 40 pounds over 8 years ago and have kept it off. I do two miles on the treadmill and 1 1/2 hours of weights four nights a week. I eat a light meal just before I work out most of the time.
(error fixed - Jill)
If you eat a snack shortly before working out, the only way that snack can provide any energy is if it’s a liquid sugar drink, which should not be a part of a routine to burn fat anyway.
In other words, eat healthy meals balanced throughout the day (good complex carb/starches (pasta), low fat, hi-protein, low on simple and refined sugars(candy, soda) and you’ll be fine…keeping calories “low”, which is relative to your size. research your caloric intake on the net. Your height, weight and fat ratio will have a bearing on it.
Complex carbs hang around for a while, so they should be eaten at lunch for a evening routine. Drink fluids in prep for workouts, and make sure aerobics are part of any workout that intends to burn fat with some degree of efficiency.
After a work out, you can eat light amounts of complex carbs, like small serving of rice, and modest amounts of protein. Keep away from simple sugars -soda, candy- and away from fats. The meal should be light, but provide just enoughn complex carbs and some protein for body repair.
Drink water, of course.
The emphasis is on a slight recharge for your body, with as few calories as possible.
I found it is best NOT to eat at least 2 hours prior to working out. Now you must establish what you are trying to do.
For instance are you trying to lose weight? Strengthen your heart? Your body?
If you are trying to lose weight
current theory holds NOT to eat. It is said that you will first burn carbs then about 20-40 minutes into your aerobics you will switch to fat burning. How do you know when this happens? It is called getting your second wind. Fat is a much more efficent fuel so when you are burning it you will know. So if you are running and you feel like you can’t go on and then suddenly you get your second wind and can go on, chances are you are now burning fat. You will continue to burn fat about 1/2 hour to 2 hours after you STOP.
If you eat before you run you are first burning the food you eat. This is why studies show working out before breakfast you lose more weight. (note the difference is a matter of a couple of pounds, not enuff to make you switch if you perfer night time work outs but enuff to be consistant with morning work out data)
If you find you run out of energy the best thing to do is eat a piece of fruit 1/2 hour BEFORE working out. Avoid carb drinks. One drink can contain 300 calories.
If you are only worrying about raising your heart rate then it is perfectly fine to eat before aerobic activity. (if it doesn’t effect you - nausea etc)
And if you are only lifting weights current theory hold very small protein amounts up to 10 grams before working out and up to 20 grams after working out (1/2 to 1 hour after)
Just a minor clarification.
‘Second wind’ is generally held to refer to the aerobic threshold, which is where the body has sorted out the blood flow, energy/waste transport and heat transfer for the muscles being used. The time at which second wind is reached varies depending on the athlete, and many non-athletes will never reach this stage, with some anaerobic metabolism occurring throughout an entire hour run. This is not to say that no fat is being burned during the entire hour session, just that the body hasn’t yet managed to switch over exclusively to fatty acid oxidation. If you never reach this second wind stage don’t worry, the amount of calories (and ultimately fat) consumed will actually be slightly higher than if you had reached it.
I also have to say that although there’s no problem with eating before working out, avoid high fat or high protein foods. The acidosis problems associated with trying to metabolise them during exercise can really cause problems.
Let’s start at the begining. You are exercising to burn fat (OP). So you want to be able to sustain a high-level workout to burn the most calories. For this you need carbs. Yes, it seems like a contradiction, but carb-fuel will allow you to burn more calories than you intake.
If you eat to soon (right before) a workout, the blood will still be in your gut digesting your food as you attempt to exercise. This will lead to ineffecent workouts, bad digestion and nausea while (or immediatly following) your workout. A balanced meal with a small amount of protien and a good supply of carbs about 2 - 21/2 hours before working out should be about right.
Just before starting, I would suggest a half of an energy bar - not a protein bar ( I like Cliff Bars[sup]tm[/sup]). While working out, drink plenty of fluids. To maintain your level of stamina I would recomend a highly diluted (with water) drink of a fluid replacement formula (e.g. Gatorade[sup]tm[/sup]).
Pick an exercise that you can do effectively so as not to reach anaerobic failure first. This might be running, biking, swimming etc.
A protien drink about 30 minutes after workouts ‘bathes’ your muscles helping them repair themselves so you can get progressively stronger (read: more efficient) workouts in the future.
Side note: Don’t over-train! This leads to fatigue which will sabatouge your efforts. Slow and easy (until your body gets used to it) wins the race!
Good luck.
I’d like to clear up a few misstatements. Fat is not a more efficient fuel than carbs. I do a lot of running, so I’ll use running as the exercise. When you first start to run, you will use (after the initial 20 seconds or so) mostly carbs, since your body can use carbs as the fuel without oxygen. Your body needs oxygen to be able to use fat. When you first start out, creatine is the source of energy, but that lasts only a few seconds. Until your metabolism is adjusted so you get enough oxygen, carbs will then be the main source of energy. Fats are slow to be digested, so if you eat at all before exercising, avoid fats. I do not eat before I run in the morning, just a glass of orange juice with powdered Vitamin C.
After you work out, ingest some carbs as quickly as you can, since they are more quickly absorbed right after a work-out. With the carbs, you should also have some proteins, not only because you need the extra protein, but it helps with the carb absorption. This is the theory behind a product called EnduroxR-4. It is a powder formulated 4:1, carbs to protein, and you are supposed to mix it with water and drink it right after a work out. The mfr states that numerous studies have demonstrated its efficacy in reducing fatigue.
I was doubtful at first. I have not seen his studies, but Roy Benson, an exercise physiologist who runs running camps, vouches for their validity. And, he says, other exercise physiologists who have seen the results of the study, concur. I run with a pharmacologist during the weekday mornings. I was discussing this with him, and, I was surprised to learn, that he takes it because of the studies he had seen.
That’s got to depend on what you mean by efficient. If you define effciency as the ratio of net energy production:net mass input, fats are a lot more efficient. In context I can’t think of another way of defining efficient. What definition are you using?
True fats are a bugger to catabolise anerobically, but that doesn’t make them less efficient as an energy source, just less versatile.
For the vast majority of people (I’ll stop short of saying all) after a workout all foods, including carbohydrates, will be absorbed more slowly than normal because blood supply is being redirected away from the gut and into the muscles, hence the reason why heavy meals following heavy excercise frequently leads to indigestion and cramps.
Again I’m puzzled as to how this coulld happen. The body isn’t going to be sythesising digestive enzymes or transport proteins using these proteins, protein/carbohydrate absorption isn’t paired AFAIK so how does it work?
A lot depends on how heavy my workout is. I walk 3 miles on an empty stomach every morning with no problem. If I run 3 miles after not eating for 12 hours or so I feel rotton and get the shakes. I can’t run right after eating so I have to wait at least three hours after a meal so I do all my runnng after work. I’ve been running for 24 years and the most important thing I’ve found is to listen to your own body. If it feels OK then it’s probably OK for you. The human body is really an awesome machine, the result of millions of years of evolutionary perfection. Yours to enjoy. My favorite pre-race food is very ripe cantelope, seems to sit well. As for eating after a workout, I walk the last half mile to my house, open the fridge, and have a beer, damn it, I earned it.
Outside Magazine had some excellent articles on sports nutrition a few months back. A lot of the suggestions apply only to top-level athletes, but there is also a lot of good info for ordinary folks too. Check out http://www.outsidemag.com/magazine/200105/200105.html --scroll down a bit to “Bodywork Special: Fitness 2001” and there is a long article and several shorter pieces.
If you are REALLY interested, there is some great info in the book, ‘Dr. Bob Arnot’s Guide to Turning Back the Clock’. He’s the senior medical correspondant for NBC news. Great book. Will answer most all your questions.
Carbos is to preferred over fats, in context, for two reasons: (1) It is more quickly digested. (2) It is more easily utilized for energy. True, fat has 9 calories per gram, while carb has 4 1/2 (IIRC), but it’s a matter of getting the energy out of that potential. You definitely don’t want to consume fat right before running or during running, but you do definitely want to consume carbos. Studies have shown that a solution of 10% carbos or less does not slow down the absorption of water while exercising. Tim Noakes, an exercise physiologist, has shown this in many studies in his book on running. This has been established by further studies and is now conventional wisdom in the running community.
The blood is being redirected to the muscles while exercising, but once the exercise is stopped, that redirection slows down and stops. I don’t have any cites off-hand (but I’ll look for them later), but its accepted knowledge that carbos are more quickly absorbed after a run and protein helps that absorption. I don’t know the mechanism, but I’ll look for some cites later. I’ve heard this from many nutritionists, have read it in Runners World, and in other sources.
[Q] Following training & competition an athlete’s glycogen stores are depleted. In order to replenish them the athlete needs to consider the speed at which carbohydrate is converted into blood glucose and transported to the muscles. The rapid replenishment of glycogen stores is important for the track athlete who has a number of races in a meeting. The rise in blood glucose levels is indicated by a foods Glycaemic Index (GI) and the faster and higher the blood glucose rises the higher the GI. Studies have shown that consuming high GI carbohydrates (approximately 1grm per kg body) within 2 hours after exercise speeds up the replenishment of glycogen stores and therefore speeds up recovery time. There are times when it is beneficial to consume lower GI carbohydrates which are absorbed slowly over a longer period of time (2-4 hours before exercise). Eating 5-6 meals or snacks a day will help maximise glycogen stores and energy levels, minimise fat storage and stabilise blood glucose and insulin levels. [/Q]
From http://www.brianmac.demon.co.uk/nutrit.htm
Actually muscle can be used as an energy source. It’s called gluconeogenesis, and it happens during prolonged activities and during severe caloric deficits, like with some diets. I was going to post a link to a good article, but for some reason a direct link doesn’t work… so go to http://www.madformountainbiking.com and type “gluconeogenesis” in the search engine. They say 10% or more of energy can come from muscle tissue.
That’s what i often hear, but i don’t understand why the average exerciser needs to quickly replenish glycogen stores. What harm would it cause to slowly restore glycogen? Recovery, it seems to me, is primarily a rebuilding of the proteins in the muscle tissue that were worn down during exercise. It would seem that this rebuilding needs to happen first before the new muscle tissue can properly accept glycogen. Otherwise it’s like a stocking a house with food before you’ve built the house! Rushing to replenish glycogen using tricks such as sugar-loading would only seem to lead to other health problems, like insulin resistance and diabetes.
A related question… Does glycogen that’s deposited into muscle immediately after an activity actually stick around until the next activity, perhaps 4-5 days later?? Or does it get converted to something else… perhaps fat?
…
“Cultivate peace and harmony with all” – George Washington
** LAO TZU ** That may be the reason that a ratio of 4:1 carbos to protein is recommended, to build back up the muscles. Quick recovery is important if you are going to exercise again that day. For example, this morning I ran 16 miles, but I had a tennis match at 3PM. I took EnduroxR-4 [supra] tm [/supra] and felt fine and not fatigued during the match.
barbitu8,
No-one is disputing that carbohydrates are the initial prefered energy source for muscles. However you stated that fat is a less efficient energy source than muscle. Fat is
a more efficient energy source. Less versatile perhaps but indisputably more effcient.
Similarly no-one is disputing that blood is eventually redirected back to the gut following excercise, but you said that food is absorbed most rapidly immediately following exercise, and this is not true.
Altho some fat is burned for energy when there are still carbs, most of the fat is not used until the carbs are exhausted. Hence, fat is less efficient.
It all depends upon the meanings of “efficient” and “immediately.”