Shorter rest periods have their place — especially if your goal is muscular endurance and fat loss. But longer rest allows you to perform more reps on subsequent sets, and this greater volume, over time, may lead to greater muscle gains in the long run. One convenient way to do this without tacking additional time onto your bodybuilding routine: Perform supersets, which are back-to-back sets of two different exercises that target non-competing muscle groups (e.g., the squat and biceps curl, or the bench press and bent over row).
Our body needs a breather. When we rest or when we sleep is the time when our body conducts a synthesis of proteins, that is, the breakdown of proteins which results in the reconstructive process of muscle building and repair. Regular and adequate rest is needed in order to gain muscle. Also, metabolism takes place during the night when we sleep, and fat is burned during this process as well. This makes sleep the most effective tool when it comes to fitness and health, and we must give our mind and body 48 hours of rest before hitting the gym again, as this is the optimum time for muscle recovery.
So when you get to that point in your leg workout where you're completely dead but have to finish an insane drop set, then you need to go to the gun scenario. Would you finish the set if there were a gun pressed against your temple? Hell yes you would, so do the damn set! As an advanced lifter, it's not supposed to be easy or "fun" and you might even puke. Just man up, find your happy place and do your damn set!
Whatever approach you take, try to do even the littlest bit more than you did last workout. It won’t be possible every day, but over time, these small increases will add up. And don’t become discouraged if gains come slower as you get older; around age 30, you’re paddling against a slow tide of gradual muscle loss that makes gaining strength and muscle tougher than when you were younger.
Increase carbs over the weekend: Increase the quantities of carbohydrates over the weekend to 1.3 times your lean body mass (fat-free bodyweight) in order to prevent your metabolism from getting used to the diet. This time, divide that number by 5 and consume the carbohydrates over Meals 1-5. Try to ensure that Meal 5 is no later than 6 p.m. so that no starchy carbs are consumed after that time.
Weight training and bodybuilding nutrition are sciences like anything else. There's biology and biochemistry and physiology, with rules and a base of evidence. Selling supplements, most of which are not needed, has become such a huge business in the commercial weight training and bodybuilding industry that it is almost impossible to know if you are getting an objective evaluation of a bodybuilding diet.
After session 12, consider whether you need to increase the weight for any particular exercise. If you can comfortably do more than the RM of 12 exercises, increase the weight by a modest amount, say two pounds or a kilogram for isolation exercise muscles such as triceps and biceps, and 5 pounds or 2.5.kilograms for compound and large muscle group exercises like squats and deadlifts. When using dumbbells, this would apply to each one. Don’t increase the number of sets beyond 3 at this time.