1. What actually is the main driver of hypertrophy
this is a VERY common topic people talk about which is pretty stupid since it’s objective not subjective. Muscle hypertrophy is solely driven by mechanical tension. Nothing else.
For those who don’t know what mechanical tension is, it’s simply the pulling force your muscle fibers experience during slow contractions. As velocity decreases, fiber force increases. (Inverse relationship).
During slow velocity contraction speeds, fibers has the most action-myosin crrosbridges- basically the most amount of force.

So how does MT create hypertrophy - it’s basically the stimulus that tells your body to add contractile tissue, mechanoreceptors within the muscle fibers detect MT, causing a series of signals that ultimately produce growth by increasing protein synthesis rate.
Heavier weight ≠ more mechanical tension btw, MT only exists on the force velocity curve, load doesn’t matter as long as contraction speed is slow. I’m not saying you shouldn’t lift heavier loads, heavier loads are helpful for other reasons. Mechanical tension and motor unit recruitment are 2 Different things.
For example, if I press a barbell with 5 kg each side (so 30 kg in total) but in slow velocity, will it create high fiber force ? The answer is yes since there is a slow contraction velocity. Don’t confuse MT with MUR.
So to clarify, you won’t grow if you only do slow contractions with light loads, This will only stimulate the active fibers, which will not be enough for growth because you are so low in the motor unit pool due to low effort.
BTW, micro tears do NOT mean more muscle gain it’s actually the opposite.
niche methods to increase MUR:
1.When it comes to warming up your muscles, the main mechanism by which their beneficial is something called Post Activation Potentiation (PAP). It’s a tool to use if you want your sets to be as stimulating and productive as possible.
PAP is a phenomenon of temporarily increasing muscle force production following a muscle contraction thus increasing recruitment of motors units, mechanical tension etc.
You can use PAP in your training by doing 1-2 reps which are 80-90% of your working set weight 30s-1m before your actual working set, and using schizo reps (will talk about it later).
So what the PAP effect does exactly you may ask? When we train, we have actin and myosin cross bridges:
Spoiler: Actin and myosin cross bridges
So what happens when you use PAP, I.e do 1-2 reps with 80-90% of your working set ?you activate your (target/goal) muscle fibers thus your myosin is prepositioned
so instead of being here:
Pre PAP actin and myosin cross bridges

The myosin gets close to the actin like shown here (used Gemini for the pic since I’m bad at editing lol):

Look at the differences in the heads of the myosin.
So when the myosin is prepositioned closer, it’s able to more sufficiently cross bridge thus we are able to have a higher rate of cross bridges leading to more mechanical tension (the main driver of muscle growth).
Worst case scenario PAP can reduce our risk of injury and best case scenario it can lead to more gains.
Another way of using PAP is doing something called “schizo reps”, if you are part of the SBL niche you probably heard about it. For those who don’t know what it is, it’s basically a few reps (3-6 ideally) where you don’t use any weight and just do the movement of your working set VERY fast right before you’re performing the working set. it follows the same pattern as doing 80-90% of your working set for 1-2 reps 30s-1m before your working set.
The schizo reps are a great option too but you can look autistic as you’re doing them.
how PAP works isn’t 100% understood but it’s probably the combination of increased motor neuron activity and biochemical processes in our muscle fibers.
2. bluetooth handles\mouth guards help increase force output by leveraging the H-reflex, or Hoffman reflex. This is essentially a measurement of your spinal cord's ability to activate muscle fibers; the higher the reflex, the more "ready" your muscles are to fire with maximum power.
This phenomenon is grounded in Sherrington’s Law of Irradiation. This law states that a muscle contracting fully will "irradiate" or spill over its energy to neighboring muscles. By creating high tension in one area, you can actually recruit more motor units in another. While many athletes focus on squeezing a fist or extending the wrist to create this tension, research suggests that clenching the jaw is actually more effective at boosting the H-reflex, so a mouth guard is great for that goal.

2. Progressive overload.
Progressive overload is one of the most nuanced topic in the fitness community. I will say this once and for all, progressive overload is a reward for gaining muscle growth, ITS NOT the cause of muscle growth, it’s the result. Dont force progressive overload, let it come to you, if it doesn’t, then you are doing something wrong. If you will force it, your form will be worse and your neurons wont adapt to the movement.
For example: if you do exercises in the 4-8 rep ranges, then when you come to 7/8 rep with good form, you can up the weight For example you did 8 reps in the bench vs in lateral raises, you won’t increase the same amount of weight, right? Then do it accordingly to the exercise.
3. Volume
Volume is the number of working sets done in a session or per week.difference between working sets and normal sets is that working sets are the one who will cause the most hypertrophy (taken close or to failure).
Too much volume can cause excessive CNS and peripheral fatigue hence your lifts will drop. And too less volume will make you leave gains on the table
I would suggest you to do the 5 sets rule in your sessions, what is it you probably ask, so the 5 sets rule is to do MAX 5 sets per muscle groups including overlap. For example- 2 sets of shoulder press and 3 sets of any chest press exercise will count as 5 sets for your front delt. So this is the maximum volume you should do per session, don’t go over it and even getting to it can be pretty fatiguing depends on your split. This way you can also find your MAV (the amount of volume you should be doing). The 5 sets rule also changes depending on your split, for exmaple if you do PPL, you will be able to do more sets than if you would be doing FullBody.
Don’t do 1 set per muscle group even if you do full body (a very CNS fatigue demanding split), do at least 2 sets. You can do 1 set per session if you really short on time or the muscle group you are doing the 1 set in is a strong point.
Also another rule you need to follow is more isn’t always better, if you can’t recover from much volume, your gains WILL hinder.
4. Intensity
Intensity for those who don’t know is how hard you go in a set. For example high intensity is going VERY hard (to failure) and low intensity is stopping a few reps from failure, the close you are to failure the most stimulating the set is.

So is going to failure every set will make you the most gains? No. Most people think going to failure is the most optimal for building muscle, but it’s really not. When you go to failure your muscles do stimulate the most, but it also makes you VERY fatigued (both CNS and peripheral fatigued), so let’s say you go to failures each set, you will get tired VERY fast which will hinder the rest of your workout performance. So what should you do? Use RIR (reps in reverse), for those of you who don’t know what it is, RIR simply means how many sets you left in reserve in your working set. For example if you did 6 sets but you could’ve done 2 more, you did 2 RIR. Also, there is a difference between 0 RIR and reaching failure, 0 RIR simply means that the next rep you stoppped 1 set away from failure. But when you reach failure it’s minus RIR since you went beyond 0 RIR. When you do 1RIR you will be less fatigued and your late session working sets will be much more stimulating since you will be able to do more reps with probably more weight as opposed to going to failure which will make you much more fatigued, so the 1-2 RIR will result in more total growth stimulus per session. Who should use RIR? I would opt RIR ONLY to advanced trainers since they are probably the only ones who can gauge their RIR and they can know what failure feels like considering they went to failure in most of their working sets. New trainers can’t gauge RIR since they don’t know what failure looks like, so I would opt for new trainers to reach failure for a few months before starting to use RIR.
So why 1 RIR can be better than 0 RIR/failure? Even tho we know failure is more stimulating, it’s also more fatiguing, which as I already said, will be worse for later sets performance. 1 RIR can be just as stimulating as well while being much less fatiguing, so you will be able to perform great in later sets. I will give you an example- if you would do a push session with 12 sets, if you take each one to failure you will get less total stimulus since after the set 5/6 ish you will get very fatigued, as opposed to if you would do 1-2 RIR you will create more stimulus since you will get dramatically less fatigue with more or less the same stimulus per set.
So how can we use it in our training to maximize hypertrophy ? It really depends on your split and how many set you got in your sessions, but I would opt for 1-2 RIR for compounds and very fatigue demanding exercises, and 0-1 RIR for isolation/single joint exercises.
5. Recovery
I will talk here about both intra session and inter session recovery.
Intra session recovery:
intra session recovery means recovery during your workout, so mainly recovery between your sets and how to keep being recovered during your whole workout. After a set that is very hard, ATP and phosphocreatine stored are depleted, metabolic byproducts like lactate and hydrogen ions accumulate, and your nervous system become temporarily fatigued, between sets, your body partially restores these systems so you can perform the next set effectively. That’s why you need to take a long rest until your next set, if rest time is too short you start the next set too fatigued which will lead to fewer reps and your CNS will be able to recruit less high threshold motor units. so how can you be 100% recovered in your workouts? First thing is resting time between sets. Most people rest 1.5-2.5 minutes per set, which is great if you are not going hard enough lol. If you go hard enough 0-2 RIR, you will need more resting time. Without much BS: for compounds I would opt for 4-5 minutes and for single joint exercise I would opt for 3-4 minutes considering you go hard in your sets. But in general, if your heart beat (get a watch to check it) is fine and went back to normal and when you feel recovered, you can start the set before the time you have set it to. During your exercises don’t be on your phone or at least don’t do anything that distracts you and take your focus away from your next set. Also, another thing 99% of people don’t do but can make your workout much much better, is to take intra workout carbs. So a bit before you reach the half of your session, take fast digesting carbs and I would opt for 30-45 G of carbs.
Inter session recovery:
Inter session is basically between each session. You get the stimulus in your training while you build it in your recovery days. So to maximize your recovery between sessions, you need to and this will be surprising, to REST

, yeah, don’t do any thing that will make your muscles tired (as examples blue collar jobs), eat a lot of carbs (200-250g). Nothing to say really, it’s that simple.
Another thing to mention is how to know if you’re recovered. So how to know that? Simple, considering you are with the same sleep or at least in the normal sleep time range (8+ hours) and you took the same preworkout and the variables before the workouts are pretty much the same then if last workout you did for example 8 sets for chest and you come this session and your strength has dropped, then you probably did too much volume for chest last time. So what to do? Get your chest volume down (so in this case to 3-4 sets) since you probably done too many last session and you can’t recover from that. So now let’s say you dropped it to 4 sets and you start progressing faster than when you did 8 sets,then that’s a great sign and it probably means 4 is close or is the amount of sets you should be doing but that’s only is assumption, so what you should do is to try different things, if you can recover from 4 sets and you progress in this sets ranges it doesn’t mean it’s how much you should do, since you didn’t try 5 sets, so what you should do is to try 5 sets for a week or two and see if you can progress on it and you recover from it, if you do, that’s great, try 6 and so on. Same goes for going backwards, so for example going to 3 sets maybe would be better and you would do the same progress as with 3 with less fatigue. So what I would recommend it’s to experiment, everyone’s got a difference genetic and there isn’t a magical number everyone should be doing in order to make progress, so check what’s better for you.