I feel this topic is hugely misunderstood, especially for those who are relatively new to training. When people think about how many times you train per week, they usually associate it with how much progress they can make, and the recovery associated with it. For example, most believe going to the gym 5 times per week is better than 4, and 4 is better than 3. But if you go 5 times per week, it will be harder to recover than 4, and 4 being harder than 3. In a practical sense, it’s close, but when creating a program, there’s more than meets the eye and it’s important to understand the implications of it to make sure we have a good training frequency adequate to the situation. Just to make things clear, in the context of this article, everytime I mention frequency, it's referring to how many times you're training per week, and not how many times you're hitting a muscle group or movement.Â
A number of training sessions per week is largely dependent on 3 factors:
1) Training age
2) Commitment
3) Preference
1) Training age
Because of diminishing returns, the more you train, the harder it is to progress. In order to continue to make progress, overtime, your overall volume is going to have to increase. And the more volume increases, the more frequency is needed, to split that volume. You could also argue that novices can recover from more volume, but would bring the discussion of MAV differences according to their respective MRVs, which would go beyond the scope of this article. Let's just take the axiom that more advanced athletes need more volume.Â
For example, if Bob needs 6 sets of squats per week to progress, he can do 2 sessions consisting of 3 sets each. However, John, who is more advanced than Bob, might need 15 sets of squats per week to progress. He can still do 2 sessions, for example the first one with 7 sets, and another with 8. But it’s a lot easier to add another session. If he now has 3 sessions instead of 2, he only has to do 5 sets per session. This is an over-simplification, but it’s just to showcase the point that over time, you need more volume, thus more sessions are beneficial.Â
2) Commitment
In very general terms, a higher number of days per week is always better. If I have an athlete that wants to have the maximum results humanly possible and he's willing to do anything, I guarantee you that I will put him on a very high frequency. However, the problem with this line of thinking is that while most people want to have the maximum amount of progress, most have restrictions on what allows them to do so. We have school, work, friends, family, hobbies, and so forth. While doing "whatever it takes" sounds great and motivational, there's more to life than being big and lifting heavy things, and most people are aware of that.Â
This to say that a higher number of days is indeed almost always better, but almost every one of us is restricted by other life factors. Training more times per week usually means prioritizing your training more, there will be fewer rest days that you can make other plans for. And even though the time in the gym might be the same, you will still spend more of your time overall. More sessions mean more gym trips, more bag preparations, more showers, etc. Most professional athletes have a very high training frequency, sometimes even training twice a day, but that’s their job. For the average guy, it might not be worth it.
For example, let’s consider plan A and plan B.
Plan A: Full-body, 3 times per week: Monday, Wednesday, Friday.Â
Plan B: Upper Lower, 3 times per week, repeated twice: Â Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.Â
Even though this is a bit of an extreme example (Plan A being almost the minimum frequency, and Plan B being almost the maximum people usually go), if the total volume is the same, the fatigue and recovery won't be that different. Plan B is simply Plan A more distributed. Each session will be a bit easier because you only have to do half the work, but at the same time, it will require more time and effort from the extra sessions.Â
People think more training sessions will impact their recovery a lot because they think about adding another session without change anything else in the program. So in this case, people would think about adding another full-body session, which would increase the total volume.
However, in the short-term, a higher training frequency is to split and distribute volume, not to add even more volume. So giving a more realistic example (and I implement this quite often) someone who has been doing full-body, can split their last training session into an upper-lower. The volume stays the same, but now the end of the week is a bit easier because you have to do less work in each session.
3) Preference
And lastly, like many other aspects of training, preference has to be taken into account. Within a certain range and as long as all the other variables are the same, how many days per week you train doesn’t matter too much in the grand scheme of things, especially if you're not an athlete doing this for a living.Â
Sure, more and shorter sessions are better, but at the same time, exercise selection, volume, frequency (in this context, defined by how many times you train a movement/muscle group) will affect your progress to a much higher degree. If you dislike going to the gym often, it’s pointless to force yourself to go to the gym 5 or 6 times per week when you can achieve the same outcome by going 3 or 4 times.
Likewise, if you really enjoying going to the gym and working out, you don’t need to restrict yourself training 4 times per week because you think more will automatically make you overtrain. It won't if you take the overall volume into account.Â
So to answer the question of how many times per week should you train, think about these 3 factors. When trying to decide how many days to go for, these are the type of questions you should be asking:Â
How long have you been training for?
Do you need a lot of volume to progress?
Can you handle that amount of volume in fewer sessions?
Are you willing to commit to a high number of sessions?
Is it worth it for your situation and life goals?
Do you enjoy going to the gym more often?
With my clients, by far the most common frequency I use is 4 times per week. It seems to strike a good balance between per-session volume and gym commitment. For novices, I very often go with 3, as they don't need that much to start with, and it's probably not a good idea to try to make huge changes in lifestyle overnight. For more advanced folks, if they're willing to, I often make programs with 5 days a week, and sometimes 6.
But the takeaway point is: view training frequency as a variable that can be changed according to your specific situation and don’t be stuck in a specific number because you are afraid it will either not be enough or that it will burn you out. It's not that black and white. Remember that volume is by far the largest contributor to fatigue.
For example, with the RP Hypertrophy app, you're able to chose the frequency you want! As low as 2x per week and as much as 6x a week with the volume adjusted accordingly to your training frequency! 
To learn even more about training volume, frequency, and everything there is to know about hypertrophy training, check out the RP Hypertrophy Hub! The grand central station for all things hypertrophy!