Muscle growth/increasing LBM is done by stimulating the body with the appropriate stimulus. Increasing load on the muscle forces growth due the body needing to adapt to be able to handle the volume of work.
The next part of that is to ensure protein synthesis is greater than protein breakdown. Consuming adequate protein and resistance training stimulates protein synthesis. http://jap.physiology.org/content/106/6/2026.full.
FYI resistance training stimulates protein synthesis for 24 hours REGARDLESS of being in a FED or Fasted state. http://www.ncbi.nlm.nih.gov/pubmed/21289204
Meaning nutrient timing is irrelevant unless you have multiple glycogen depleting sessions for the same group of muscles in the one day and have limited time to get nutrients in before the next session. Carbohydrates for replenishment of glycogen can be consumed over a 24hr period to achieve full levels.
When a subject exercises, muscle glycogen declines and is slowly restored over the following 24 h if carbohydrate intake is normal. Not to mention Glycogen also starts to be replenished even without the presence of carbohydrates http://www.ncbi.nlm.nih.gov/pubmed/705238?dopt=Abstract
Therefore, when two exercise sessions of 1 h is separated by 2 h, the second bout of exercise is undertaken with low muscle glycogen at its start, whereas muscle glycogen is restored before each exercise bout when the exercise is separated by 24 h. http://jn.nutrition.org/content/132/10/3228S.full
Also carbohydrate type is irrelevant on either performance or replenishment. http://www.jissn.com/content/8/1/15
Consuming adequate protein in time of CALORIE DEFICITS limits any LMB losses http://www.ncbi.nlm.nih.gov/pubmed/19927027 and ensuring the calorie deficit is not excessive LBM gains can be made http://www.ncbi.nlm.nih.gov/pubmed/21558571
Protein synthesis is stimulated at a great rate with the ingestion of >1.5g/kg and REGARDLESS of frequency makes NO difference in the protein retention. http://jn.nutrition.org/content/132/10/3228S.full
There are many different pathways/methods go into increasing LBM and decreasing BF, but on the basis it is being in a calorie deficit will induce BF decreases (due to the BF being the primary source of STORED ENERGY) and ensuring protein synthesis is greater than protein breakdown (via adequate protein and performing resistance training).
Now being in a calorie SURPLUS will allow for muscle gain at optimum/fast rates. Also the amount of BF will also play a part in how fast an increase in LBM can occur.
An individual with a higher BF will have the ability to gain LBM at a fast rate due to of course a higher amount of STORED ENERGY. That should seem quite common sense. For a leaner individual of course it is the harder/close to impossible to drop BF and increase LBM, and at that it is a SLOW rate. Mainly due to hormonal functions, but that is beyond the realms of this essay.
There are macronutirent and calorie cycling methods that can be used to maximize LBM gains while dieting and for the most part unless you are a competitive NATURAL bodybuilder and have hormonal imbalances there is no real need to even focus on that but for completeness I will go into some protocols for carbohydrate cycling.
The process of carbohydrate loading/cycling when dieting (dropping body fat while attempting to gain/maintain muscle or enhance exercise performance) has been the subject of many different protocols over the years.
The primary purpose of carbohydrate loading/cycling is to A) refill muscle glycogen and B) manipulate hormonal function (Thyroid,Leptin and Insulin).
PLEASE NOTE – Depending on the individual’s bodyfat levels, goal (desired body fat& overall composition), hormonal function, general day-to-day activity and training volume, carbohydrate cycling/loading may or may not be required/beneficial. Each case should be looked at on it’s own merits.
While long-term macronutrient, calorie intake and training stimulus determine body composition, it can be a little deep than that. Hormonal function and exercise performance also play a part in body composition, be it indirectly (stimulus load/volume ability – exercise performance) or directly (BMR and overall EE – hormonal function).
The two main carbohydrate loading/cycling protocols are the A) higher carbohydrate intake on training days (with lower fats and at maintenance calories or just above) and lower carbohydrate intake on non training days (with higher fats and in a calorie deficit) or B) 4 or 5 days of low carbohydrate intake followed be 3 or 2 of higher carbohydrate intake.
I could go quite in-depth on protocol’s pros and cons but IMO the only real thing that matters is what suits the individuals schedule and what ultimately allows for the best long term dietary adherence.
Martin Berkhan’s protocol (training days cycling) - http://www.leangains.com/2010/03/intermittent-fasting-set-point-and.html
Lyle McDonald’s protocol (back to back day loading) - http://www.simplyshredded.com/research-review-an-in-depth-look-into-carbing-up-on-the-cyclical-ketogenic-diet-with-lyle-mcdonald.html
I normally suggest a 4 or 5-day of low carbohydrate intake (while in a calorie deficit) followed by 3 or 2 days of carbohydrate loading (eating at maintenance or slightly above 5-10%). So the net result at the end of the cycle is still a calorie deficit, all be it small. I also find that the easiest way to adhere to the calorie requirements for the long term and also allowing for some added flexibility during the more social parts of the week (the weekend).
Even thought muscle glycogen is restored and can be restored in 1 day (with the right carbohydrate intake), other mechanisms like hormonal function have more of a positive reaction for the length of time with increased carbohydrate consumption not simply total amount consumed.
Expanding on exercise performance point. The existing exercise performance data (all be it done on endurance cardiovascular exercise) is mixed. Studies have suggested that once adaptations to the utilization of fat for fuel (5 days), a shorter carbohydrate load (1 day) still may not be enough to improve exercise performance. For a more in-depth look, check out this article by Lyle McDonald - http://www.bodyrecomposition.com/training/cyclical-ketogenic-diets-and-endurance-performance-qa.html
So with that in mind, from a performance point of view, maybe a more regular and more moderate cycling period may be of some benefit.
The key point being the amount of carbohydrates to be consumed, the length of time with increased consumption, the amount being used during exercise and the amount we can store that ultimately lead manipulating intake to maximize muscle gain or at least maintaining muscle while dropping body fat.
Carbohydrate amount does not equal the amount of glycogen. They have separate units of measure are not of equal quantities/units of measure. 5.5 grams of carbohydrates = 1 millimole (mmol) of glycogen.
Trained individuals have higher glycogen storage abilities both due to dietary carbohydrate intake and larger/active muscle tissues. They (athletes) have glycogen levels at 110-130 mmol/kg.
Fat oxidization increases at rest and during aerobic exercise at muscle glycogen levels of 70 mmol/kg (or 12 grams carbohydrates/kg). Levels below 40 mmol/kg = 7 grams of carbohydrates/kg impairs exercise performance and increases the potential for protein to be used as fuel.
Glycogen super-compensation can increase levels to 175 mmol/kg if glycogen is depleted to a great amount (which is around 25-30 mmol/kg). Total exhaustion during exercise occurs when levels drop to 15-25 mmol/kg and the enzymes for super-compensation are also impaired at that level (below 25 mmol/kg).
At 70% 1RM, glycogen is depleted at approx. 1.3 mmol/kg/repetition. Basically for every 2 sets of 10 reps, you will use 5.5 grams of carbohydrates as fuel. Endurance athletes will use more during a training session compared to a weight lifter.