i’ve always heard that you have to eat within the window of opportunity after a exercising…
but i don’t understand it… perhaps it’s valid for a long activity, but:
suppose i run for an hour. suppose i ate well hours before the run.
according to another myth i should have about 2000 calories stored in my liver and muscles before the run.
an hour run would deplete about 800 calories…
at the end of the run i should have enough calories and to run for another hour
why should i eat?
that’s from the carbs perspective.
now from the protein perspective:
an hour run should use up about 5% of the calories from protein.
5% of 800 calories is 40 calories. if i’m not mistaken that’s what you get from eating 5 grams of protein.
so, 5 grams… isn’t that negligible? that’s like one quarter of a single slice of turkey breast…
so, i’m thinking of all these people that run for an hour and then indulge themselves in the feast
called “window of opportunity”…
isn’t that a myth?
Restoring those 2,000 calories in your muscles and liver isn’t as simple as eating dinner that evening. It can take several days to restore glycogen stores. That’s where the 30-min window comes in. Your cells are much more receptive to reuptake during that time, which is why you want to eat during that time.
edit: Also, your body isn’t a car, where all gas works as well at 90% as at 30% full. There are tons of physiological changes that start to happen when your body gets below x number of calories in glycogen (“Hangry” is the most obvious manifestation). Obviously, that number is different for everyone, and can be changed, but your body works best (in terms of recovery, performance, and strength) when it is close to fully fueled.
As for recovery food, chocolate milk is as good as some recovery drinks.
Think your body is supposed to be more receptive to using the protein in the places where it is needed more directly after exercising. Also your body is still working replenishing the muscles so eating then also speeds up recovery. Either of those or it really don’t matter a calorie burned is a calorie burned and likewise a calorie in is a calorie in.
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so, i’m thinking of all these people that run for an hour and then indulge themselves in the feast
called “window of opportunity”…
isn’t that a myth?
How often are you training? There is a measurable difference in muscle glycogen levels in the short term between those who fuel during the “window” and those who rely on regular meals.
At 24 hours after exercise, muscle glycogen levels are effectively equal, so, 2/days or more - eat a little snack. 1/days - just eat your meals.
There is a point after exercise that you body absorbs and stores glycogen the best, where that is, is debatable but I think most people agree it’s within 30 minutes.
I wouldn’t be concerned about where you get the calories from I would just be concerned that you get a couple hundred calories shortly after your workout.
After that I would eat balanced meals for the rest of the day.
You appear to be asking a lot of energy and nutritional questions lately. I would suggest that you read “The Lore or Running” by Tim Noakes. That will answer a lot of your questions and you won’t have to decifer between the BS, myth and the truth.
I, personally, find that if I do a big run or bike and then get distracted from eating for the next few hours, I feel like shit and get headaches. Usually the next day will suffer from my lack of proper recovery. Im not a doctor but I have improperly not listened to my body enough to know that I should be at least giving it something to munch on following a big workout.
In an evolutionary sense, most of the time you’d be running to catch your dinner. If you caught it and ate it quickly, then you’d be rewarded with a recovery benefit that would promote your survival relative to someone else that was too slow to catch their meal. They would not recover well From their run and be more likely to get weeded out of the population. Just an odd theory but maybe it has some merit.
Plenty of studies have been done that have shown that while the window of oppurtunity does exist, unless you are a performance athlete that needs to perform twice a day (eg elite athlete training twice a day), it is grossly over rated and simply eating a balanced when you feel hungry after your workout is good enough for most people and will refill glycogen stores before your next workout.
i’ve always heard that you have to eat within the window of opportunity after a exercising…
but i don’t understand it… perhaps it’s valid for a long activity, but:
suppose i run for an hour. suppose i ate well hours before the run.
**according to another myth i should have about 2000 calories stored in my liver and muscles before the run. **
an hour run would deplete about 800 calories…
at the end of the run i should have enough calories and to run for another hour
why should i eat?
that’s from the carbs perspective.
now from the protein perspective:
an hour run should use up about 5% of the calories from protein.
**5% of 800 calories is 40 calories. if i’m not mistaken that’s what you get from eating 5 grams of protein. **
so, 5 grams… isn’t that negligible? that’s like one quarter of a single slice of turkey breast…
so, i’m thinking of all these people that run for an hour and then indulge themselves in the feast
called “window of opportunity”…
isn’t that a myth?
Your body can only store about 2k calories in your liver and muscles before activity starts. think of it as a full tank, You can carb load all you want, but your body can only store so many carbs.
There are 4 calories of protein per gram, so 40 calories would be 8 grams of protein. The amount of protein you should take in depends on your body weight and what part of the season you are in. For example most triathletes are in a prep cycle right now so intake should be between 1.2-2.5 g/kg, roughly. Eat towards the lower end of that value if you want to maintain body weight, higher if you want to increase your weight.
As for the window of opportunity, think of protein as a repair system for your body. While you exercise you are damaging the muscle cells continually, and protein is the nutrient in your body that helps repair, recover, and strengthen your body. The earlier you get the protein into your body, the earlier you can start the recovery process.
Blood sugar also runs low after long bouts of excerise and eating more protein will stabilize your blood sugar levels, which in turn, controls the bodies biological hunger response as well.
Re the 30 min window, when I do a 2 hr workout in the am prior to eating anything and have water only during the workout, I understand it’s optimal to eat within 30 min, which I do. However, if I did a 1 hr workout and waited another hour to eat something, is the replenishing rate poorer?
Plenty of studies have been done that have shown that while the window of oppurtunity does exist, unless you are a performance athlete that needs to perform twice a day (eg elite athlete training twice a day), it is grossly over rated and simply eating a balanced when you feel hungry after your workout is good enough for most people and will refill glycogen stores before your next workout.
hey, thanks. i believe in that. i don’t always eat during the window and i’ve never felt any difference between when i eat and when i don’t eat…
is there any chance you can dig out a link to one article/study that shows this?
Re the 30 min window, when I do a 2 hr workout in the am prior to eating anything and have water only during the workout, I understand it’s optimal to eat within 30 min, which I do. However, if I did a 1 hr workout and waited another hour to eat something, is the replenishing rate poorer?
Over a 12 hour time, yes. Over 24 hours, no. I’d post a slide from the applicable study, but I’m on the road now. Bottom line - if you’re doing 2/days, hit the refuel button right after a workout. If you’re 1/day, don’t sweat it.
Re the 30 min window, when I do a 2 hr workout in the am prior to eating anything and have water only during the workout, I understand it’s optimal to eat within 30 min, which I do. However, if I did a 1 hr workout and waited another hour to eat something, is the replenishing rate poorer?
I would be very careful about doing those 2 hr workouts prior to eating anything. Any fat-burning benefit may be offset by the detrimental metabolic reactions in your body from doing these “starvation” style, especially if you are doing them even slightly too hard, or even mixed into a 64 hour period where these is any intense training. Matt Dixon sums it up nicely here http://triathlon.competitor.com/2011/04/nutrition/is-depriving-yourself-of-calories-in-training-a-good-idea_26198
In terms of your question (and the general discussion) about the replenishing rate, I look at this a lot like Global Warming. You can find studies that say everything, but no one can argue that using less emitting fuels would hurt. Much the same, if you have to eat 2000 to 5000 calories everyday (depending on training levels), and at least half of those probably come from carbs, you can probably sneak 300 calories worth (e.g., not much of your daily intake) in after a workout, along with some protein too…at best it helps you, at worst it doesn’t hurt you.
Re the 30 min window, when I do a 2 hr workout in the am prior to eating anything and have water only during the workout, I understand it’s optimal to eat within 30 min, which I do. However, if I did a 1 hr workout and waited another hour to eat something, is the replenishing rate poorer?
I would be very careful about doing those 2 hr workouts prior to eating anything. Any fat-burning benefit may be offset by the detrimental metabolic reactions in your body from doing these “starvation” style, especially if you are doing them even slightly too hard, or even mixed into a 64 hour period where these is any intense training. Matt Dixon sums it up nicely here http://triathlon.competitor.com/...ng-a-good-idea_26198
Possibly true, but while the exercise may be at a lower intensity because of the depletion, the gains in things like mitochondrial density and increased fat burning may offset it.
Med Sci Sports Exerc. 2010 Nov;42(11):2046-55.
Training with low muscle glycogen enhances fat metabolism in well-trained cyclists.
Hulston CJ, Venables MC, Mann CH, Martin C, Philp A, Baar K, Jeukendrup AE.
J Appl Physiol. 2008 Nov;105(5):1462-70. Epub 2008 Sep 4.
Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens.
Yeo WK, Paton CD, Garnham AP, Burke LM, Carey AL, Hawley JA.