Would you recommend that I increase by 357 calories to each day now? Also, is adding more calories to training days a logical approach rather than eating the same amount every day?
Here is a few things to consider:
Small fluctuations in weight like what you described are most likely due to changes in glycogen storage and water weight.
Stop counting calories. I believe that counting calories only makes sense if you are trying to lose fat. If you are trying to gain muscle then eat until you are fully satisfied and then maybe eat a little more than that. Instead of counting calories count reps, sets, and poundages for your exercises and count inches on a measuring tape around your arms and legs. If you don't feel very hungey then don't force yourself to eat just to consume a certian amount of calories because your muscles and liver might become less sensitive to insulin and then any weight you gain will just be fat. A mass building diet should be more instinctive and less regimented than a fat loss diet.
Do some mild cardio. Doing mild cardio(like walking on a treadmill) while trying to gain muscle will increase your insulin sensitivity so you will metabolize nutrients more effectivly. It will also speed up your metabolism; you may be thinking that the last thing that you want to do while trying to gain muscle is to speed up your metabolism but this will actually help you gain muscle by increasing your appetite and it will allow you to eat more frequent and larger meals without gaining much fat. Having a faster metabolism and eating more food will also speed up your recovery from weight training because you will be able to supply your growing muscles with more nutrients while burning any excess energy that might decrease your appetite or be stored as fat. Doing mild cardio will also speed up your recovery from weight training by increasing peripheral blood flow. When doing cardio during a mass building phase it is especially important to stay near your target heart rate so that your body does not switch from burning fatty acids and blood sugar to glycogen and creatine phosphate. Also don't do your cardio in the morning on an empty stomach or before you sleep like you would if you were trying to loose fat and don't do it very often, maybe once a day only 2-3 times a week. You may be thinking that most professional bodybuilders don't usually do cardio during a mass building phase but consider that they are usually using alot of performance enhancing drugs, they often weight train twice a day, and they already spend a large portion of the year dieting very strictly and doing alot of cardio.
Cycle your carbohydrates. I suggest that 3-4 days a week you dramatically increase the amount of high glycemic carbohydrates. You could buy a large bottle of grape juice(avoid high fructose carb sources) and consume it over 3-4 days with meals or even sip on it between meals. When the bottle is gone wait 3-4 days before you open another one and return to your usual carb intake. Taking breaks between these short high carb cycles will allow your body to remain sensitive to insulin and it will hopefully prevent all of this extra sugar from being converted to fat. Temporarily dramatically increasing your carb intake like this should increase your strength and muscular endurance because it will increase the amount of glycogen stored in your muscles and liver, and you will probably notice more muscle fullness and great pumps in the gym, it will cause a fast gain in weight because for every gram of glycogen your body stores three grams of water is also stored along with it(this weight gain caused by cell volumization has also been shown in studies to trigger protien synthesis), and the increase in carbs will correspondingly increase your insulin levels(insulin is released in response to rising blood sugar) and as you probably know insulin is the most anabolic hormone in the body because it signals cells to take in amino acids, sugar, and fatty acids.
Consume most of your carbohydrates in the morning and immediatly after your workout. I'm sure that you already know that it is extremely important to ingest a high glycemic carbohydrate after your workout, but the point I'm trying to make here is that it is wise to let your blood sugar and insulin levels fall in the evening before you sleep. The reason for this is three fold. Doing this will increase your growth hormone release while you sleep. Growth hormone is released in response to exercise, REM sleep, and low blood sugar. If you let your blood sugar fall before you sleep your night time growth hormone levels will be higher. Letting your blood sugar levels and your insulin levels fall at night will give your insulin receptors time to upgrade and you will be more insulin sensitive in the morning when you ingest a larger amount of carbs. This last reason might be the most beneficial reason to let your blood sugar levels fall at night. If you eat something high in fat and slowly absorbed protien like steak, salmon, or whole eggs for your last meal of the day your body will have a constant flow of nutrients throughout the night which will allow you to build muscle while you sleep, which is the most anabolic time because this is when the body uses most of its energy to grow and repair itself.
Take longer rest periods between sets. This will allow you to lift more weight and perform more reps. The longer you rest between sets the more your body will be able to re-balance PH, remove waste products, and regenerate local energy storage. Some might say that waiting too long between sets may prevent you from getting as pumped up as possible and this can sometimes be true, but I have a solution for that. At the very end of your workout pick 3-4 exercises for the same muscle group and while using a weight that is not much heavier than what you would normaly warm-up with do 15-30 reps of each exercise, one after another, with no rest in between each set; this should get you extremely pumped up before you leave the gym. Another similar technique you could try at the end of your workout for a great pump is either FST-7 or crazy 8's which requires that you do 7 sets of 7 reps or 8 sets of 8 reps with a relativly light weight with very little in between sets.
Change up your exercises. If you normally do back squats then try front squats instead. If you normally do over-hand bent-over rows try under-hand bent-over rows. Small changes like this will stimulate new growth and maintain the muscle mass that you already have and you might also find a new favorite exercise.
Finally. DON'T GIVE UP. Hitting a plateau can be frustrating but I assure you that you can find a way to break through it, whether it is going to take a change in your dietary habits, your exercise technique, your lifestyle, your training philosophy, your motivation level, or your attitude, you can succeed. Set realistic and logical goals and work towards then one step at a time. It is great that you are willing to ask for advise from others who are chasing the same goal(although at this point you might be wishing that you hadn't because now you have got this crazy guy rambling on and on in your thread:blink
. Don't make your goal simply to gain X amount of pounds, the only people that want to just gain weight, regardless of how much of that weight is muscle, are sumo wrestlers. At one point, after bobybuilding for many years and then hitting a plateau, I set a goal to just put a quarter inch on my arms and legs. Since then, after trying different things and learning what would cause my body to gain that quarter inch, I have put an inch and a half on my arms and two inches on my legs, gotten stronger than I ever believed I could be and lost alot of fat in the process. Set small goals like that and chase them, but when I say don't give up I don't just mean don't give up on the small goals you may have relating to bodybuilding, I mean don't give up on what is really important to you. If you have things in your life like work, school, or family that are getting in the way of these smaller goals recognize that neglecting these priorities, even though in the short term it may help you achieve your smaller goal, might actually prevent you from being able to do the things you love, like bodybuilding, in the long term. I say this because the things that are holding you back from achieving a short term goal like gaining some muscle might not have anything to do with your diet or exercise technique but may be something unrelated, and more important, that simply keeps you from putting enough energy into chasing your short term goal. If this is the case, as it has been for me in the past, then don't beat yourself up or wonder what your doing wrong but understand that you might need to wait for a better time in the future to achieve your short term goal, but don't give up on it.