Eating training calories back and rate of assimilation

Yogi_Carl

I have been thinking on this one and have come to something that others here may not have thought of. Apologies if this has already been covered.

If one day I total up 1000 training calories the simple math is that I can eat back 1000 calories and not expect to gain weight; calories out, calories in. That is fine, except that the rate at which calories can be assimilated by the body is presumably constant, so if my 1000 exercise calories of proteins and carbohydrates are not used at the rate my body can assimilate them, they will be stored as fat even if they were needed for repair and recharge of glycogen.

Similarly, if I weight train and I need say 100g of protein to repair and possibly grow but my body can only assimilate 50g of protein at a constant rate, the other 50g will be changed to and stored as fat. Once it is stored as fat it cannot be broken down by the body to make protein once the body has caught up again.

The solution would be to take those 1000 exercise caloriea and share them over the next 48 hours so the body can use them back over a longer period of time more in line with the body's assimilation rate. This way, protein would be used for repair, carbs would be stored in the muscles as ready energy and less of the calories would be stored as fat which is what most of us here are trying to reduce.

It makes me wonder therefore if, instead of eating training calories back on the days we exercise and possibly feel stuffed or just not eat them back because we are not hungry, we should just look at our base MFP settings and step our activity level up by one - so sedentary to light, light to moderate etc and not log the exercise calories as calories to eat back - certainly less to worry about and we wouldn't have heavy and light eating days to consider.

Am I right? I hope there are professionals on here who could give a more accurate viewpoint of how long it takes for the body to assimilate components and whether it makes sense to eat back exercise calories all at once or whetehr it makes better sense to share them across the week.

SideSteel

If one day I total up 1000 training calories the simple math is that I can eat back 1000 calories and not expect to gain weight; calories out, calories in. That is fine, except that the rate at which calories can be assimilated by the body is presumably constant, so if my 1000 exercise calories of proteins and carbohydrates are not used at the rate my body can assimilate them, they will be stored as fat even if they were needed for repair and recharge of glycogen.

You are continually balancing periods of fat storage and fat oxidation. What matters is the net difference between the two. Using your scenario, if you ate huge meals that were somehow beyond your limits to utilize, you would either be offsetting previous fat oxidation or you would be oxidizing any fat storage that may occur post-eating. This will still be governed by energy balance over time.


Taking this to an extreme: If you were to eat 1 meal per day, using your assimilation concept, one could argue that you're eating way too much in one sitting and you're causing undue fat storage due to the huge-*kitten* meal you just ate. In the acute sense this is true, but in the long-term sense it's irrelevant because you also spent a very long period of time oxidizing fat during your non-feeding time.

Let me know if I totally misunderstood your premise.

nxd10

I think that's why it's more important to try to balance net calories over the week but to keep input steady enough that you always have enough easily accessible stored fat/sugar to use.

Yogi_Carl

thanks both

"Let me know if I totally misunderstood your premise. " - I think we are both in agreement with the theory of expenditure and replacement of energy. The place where this breaks down is where I need a certain amount of protein after a strength workout where I need to replace proteins to help repair and perhaps build muscle mass.

If I eat the full amount of protein back in too short a time, I may find that some of that protein has been stored as fat. Once it has been broken down and stored as fat, it cannot be converted back to protein. So I could end up with an excess of fat and not enough protein although I did eat enough protein for my body's needs.

So the proteins I would need to do a job of repair would be better shared across the week or several days rather than eating them all back on the day I did the lifting work.

So I conclude that I (or anyone) would be better to increase their daily activity setting on MFP rather than eating back calories as and when they exercise.

Also I don't enjoy eating large one day and then not on lower activity days - too much up and down.

I am going to try increasing my basic activity setting and not including exercise calories for a while and compare development and see how it goes.

EvgeniZyntx

That is fine, except that the rate at which calories can be assimilated by the body is presumably constant, so if my 1000 exercise calories of proteins and carbohydrates are not used at the rate my body can assimilate them, they will be stored as fat even if they were needed for repair and recharge of glycogen.

This is incorrect. These processes are far from constant.
In the simplest sense think of swimmers like Phelps.

We can discuss the rate limited step of fatty acid synthesis in the liver - fat storage rates are also limited.

SideSteel

If I eat the full amount of protein back in too short a time, I may find that some of that protein has been stored as fat. Once it has been broken down and stored as fat, it cannot be converted back to protein. So I could end up with an excess of fat and not enough protein although I did eat enough protein for my body's needs.

I would question whether or not you can create an acute demand for protein that is beyond your ability to digest/utilize.

So the proteins I would need to do a job of repair would be better shared across the week or several days rather than eating them all back on the day I did the lifting work.

Again, I don't think this condition exists. Not trying to be difficult here, it's just that I don't think you can physiologically create a net demand for protein that is beyond your digestive limits. I would say the same about other macronutrients.

Now I DO think that you may not maximize substrate utilization in specific scenarios if you have a really goofy nutrient timing procedure (for example I wouldn't find it ideal for LBM to fast for 3 days and then eat 4 days of protein in one dose) but if we eliminate what I would call "dietary silliness" and just discuss relatively real-world eating protocols, I don't think your scenario is an issue.

Also I don't enjoy eating large one day and then not on lower activity days - too much up and down.

I am going to try increasing my basic activity setting and not including exercise calories for a while and compare development and see how it goes.

But all that being said -- if you WANT to average out your intake so that generally speaking, the ups and downs are smoother, nothing wrong with that. I do that myself. I just have a handle on my average TDEE and I eat according to it regardless of whether it's a training day or rest day. I'll continue to do so unless I get to a point that I am convinced that another method is superior given my training experience/physique/etc (I don't believe these things are important for the majority -- for a competitive bodybuilder, possibly).

Yogi_Carl

thanks zyntx - so are you saying that my eating back of exercise calories/components should be reactive to whatever exercise volume or type (whether cardio or strength work) per day to maximise effect rather than balancing out across the week as I have suggested?

What I would want to avoid is feeling that I am overeating on days where I have amassed large calorie deficits through exercise, but making sure that I am not in too large a deficit simply because I cannot eat enough for comfort. I am guessing it would be fine to split exercise calories of one day - for exmple 1000 extra calories - over two or three days rather than eating them fully or partially back on the day of exercise.

Yogi_Carl

Thanks SideSteel - that's making good sense. I can see that it would be extremely difficult to create such protein deficits in real terms and that even-ing out any exercise calories over more then the exercise day itself for comfort's sake is also acceptable.

I think we've ironed this one out - thanks everyone. :flowerforyou:

SideSteel

thanks zyntx - so are you saying that my eating back of exercise calories/components should be reactive to whatever exercise volume or type (whether cardio or strength work) per day to maximise effect rather than balancing out across the week as I have suggested?

What I would want to avoid is feeling that I am overeating on days where I have amassed large calorie deficits through exercise, but making sure that I am not in too large a deficit simply because I cannot eat enough for comfort. I am guessing it would be fine to split exercise calories of one day - for exmple 1000 extra calories - over two or three days rather than eating them fully or partially back on the day of exercise.

In terms of body composition I would speculate that spreading out your calories in an effort to smooth out the peaks and valleys that are created by an exercise-calorie model, would be just fine. I would suspect the differences in your physique over the course of time when comparing the two methods would be minimal, given the same average intake of calories and macronutrients AND given that your training intensity isn't effected by these changes.

fugaj01

"Similarly, if I weight train and I need say 100g of protein to repair and possibly grow but my body can only assimilate 50g of protein at a constant rate, the other 50g will be changed to and stored as fat. Once it is stored as fat it cannot be broken down by the body to make protein once the body has caught up again. "

SideSteel and Zyntx answered most everything else, but wanted to state that the above is not a complete reflection of how protein is used or digested. I am not an expert, but from what i have read protein is digested slower than the other macros, and because it takes more engery to digest... approx 2/3 (if i recall correctly) of the protein consumed is available for use other than digestion. Only then, if not all used will it be stored as fat. So if you take in 100g of protien and and use only 50g, only about 15-20grams could be stored as fat. The rest was used in the digestive process.

Just thought I would add two cents in.

EvgeniZyntx

thanks zyntx - so are you saying that my eating back of exercise calories/components should be reactive to whatever exercise volume or type (whether cardio or strength work) per day to maximise effect rather than balancing out across the week as I have suggested?

What I would want to avoid is feeling that I am overeating on days where I have amassed large calorie deficits through exercise, but making sure that I am not in too large a deficit simply because I cannot eat enough for comfort. I am guessing it would be fine to split exercise calories of one day - for exmple 1000 extra calories - over two or three days rather than eating them fully or partially back on the day of exercise.

In terms of body composition I would speculate that spreading out your calories in an effort to smooth out the peaks and valleys that are created by an exercise-calorie model, would be just fine. I would suspect the differences in your physique over the course of time when comparing the two methods would be minimal, given the same average intake of calories and macronutrients AND given that your training intensity isn't effected by these changes.

I'd tend to agree with this with one/two variations.

Short answer: yes several days is fine and do not hesitate to *not* eat those 1000 calories if you do not feel a need for them one week or another. You do not need to eat back *all* your calories - remember TDEE and BMR are estimates that you need to adjust based on experience on how things are going. You do need to eat a lot of them if you are doing heavy work (last winter I was apparently burning 5000 calories above BMR for two weeks in a hard ice hike in the Zanzkar).

longer answer: if you are doing high intensity activity, long rides, marathons, glycogen storage is a "fast" process and while I'm not a fan of the glycogen window myths for extreme efforts (like these multiday rides or centuries) it is important to maintain glycogen stores during and after the effort to be ready for the next day. Eat foods or pastes/energy gu (AND DRINK) that you know will not upset your digestion. This is more important then than calorie in - out.

for body builders there does seem to be some evidence for pre-workout eating for muscle growth.
for weight loss during cardio, I would guess (this is a guess) that it reduces the effect of glucagon on fat mobilization. Edit: But this is really not something we should focus on - these minutae keep people from focusing on the basics.

Yogi_Carl

Thanks everyone. I would just like to add this thread has been the most agreeable and informative I have had the pleasure to partake in and has really helped to clear the bigger picture for me.

Cheers!

EvgeniZyntx

Welcome! Pleasure.

One thing you can also do - this is old data from when I was in college -- I believe that the max that the glycogen storage that you can get (lets say you "depleted" it with exercise) in reload is about an additional 500g of carbohydrates (total system is 15g/kg) BEFORE fat storage (de novo lipogenesis) is significantly activated (it is still being created prior to that level but glycogen re-storage is occurring much faster).

500g of carbohydrates is a metric truckload (10 x 500g chocolate bar), don't worry about the first pizza... IIFYM.

This was a nutrition study in 1988 on human lipogenesis but I don't remember author or title.

edit: BTW - I'm no true expert and the info I provide can be much weaker than that provided by others here -- Sidesteel is an awesome source. My background credentials are Biomed Engineer with Biomaterials/Biology (and research in tissue culture) focus more interested in cellular adhesion and certain functional physiologies than nutrition, just now getting re-educated on that.