Come inside - you may want to take a look.
Around March of this year (2012), I was absolutely exausted. I was working at least 12 hours each day as a minimum (Sunday was around 4-5), and the relentless workload just wouldn't ease up. Something had to give; so I sat down and examined my lifestyle thoroughly and decided it was time to make some sacrifices. Could I give up my financial income? No, it wasn't plausible. I'm living in Hong Kong and it's an expensive, pretentious city to some extent, and slashing my finances wouldn't bode well. I was certain of this and still am. Could I sacrifice my social life to some extent? The answer was absolutely not: I work so hard that I at least enjoy one free night through the week to eat with friends and until I turn celibate, I won't be giving up Saturday nights out as that's an inherent part of my biological drive (whether I'm always successful or not is irrelevant...). I was left with one key time consuming activity in my life: training. It was inevitable that it had to give.
Something just had to give in my life.
I've been training four days per week practically since I began training over 7 years ago. I've followed every plausible split: the usual Mon/Tue/Thurs/Fri style bodybuilding-hypertrophy stuff, Wendler's 5/3/1, Yates' style HIT, Layne Norton's power-hypertrophy programme and more. All of them, to some degree, have worked well - as long as I was adhering to the concept of progressive resistance, I achieved results with each split.
When I used some deductive reasoning (which if you've followed my articles before, I simply love to bring this concept up), I was left with something pretty obvious: it was never the time I spent in the gym that allowed me to achieve results, it was always what and how I was spending my time and focusing on the key components to make myself a better, faster, stronger individual, that was delivering results. In a nutshell: the efficient movements I was doing all provided results to varying degrees. However, the unfortunate thing, is that I have been guilty of wasting a lot of time that could've been invested in more productive ventures.
It's not as simple as it sounds though. When you are as meticulous as you should be when you're truly in love with this sport / fitness lifestyle, you realise that it is an incredibly complex, enormous compilation of information that contrasts and juxtaposes every aspect so perplexingly. In short, there are too many right and also too many wrong answers to truly cement a case for what's optimal for one individual and what's not for another.
However, I hope at least some of you are able to resonate with the following advantages I have discovered when training three days per week as opposed to four, as I have found that one additional day in the gym to now be of detriment given my lifestyle, but not only that, I now currently believe that three day training per week has several very distinctive advantages over four days per week that I'm about to elaborate on.
Important Note: The following is not applicable to individuals taking anabolic steroids / PH's or other exogenous hormones that can enhance body composition and performance. The reason for this is quite simple: people who use these compounds are able to train at a higher frequency, recovery a lot faster, and thus have more potential for growth and improved performance in a much shorter period of time. It's not just a small difference either: AAS and performance enhancers often provide huge benefits over natural trainees, and I believe the disparity to be so great that as such I don't recommend this advice I'm about to present to be followed by users of these compounds, unless you're specifically on a break from them or have discontinued their usage.
You feel more motivated
I think it's only fair to start on a slightly contentious point but one that I believe may hold strong value for anybody considering a switch over from 4+ days per week. After all, to make something work, you have to have a desire and motivation for it to be successful and anybody who's ever tried continuously training whilst unmotivated will no that it's simply an ineffective waste of time.
Hence, I believe three days is superior for motivational reasons. When you realise you'll be training only once every two days (or three times in seven days, alternatively), you're extremely focused on being productive in those given sessions as you don't have a lot of leeway to mess up. You may argue to the contrary and say that the more you go to the gym, the more motivated you feel - that's a completely valid point. However, when you tease yourself with three times per week, the potential to mess up is a lot less and this leads me on to my next point nicely...
You'll be more efficient with your time in the gym
It's unlikely that you'll have the leverage that four-to-five days per week offers you to mess around with tons of unnecessary bicep curls, kickbacks, etc. When you train three days per week, it's very probably that you'll have a big compound lift on that given day and as such your assistance work will follow suit in supporting that. Likewise, as aforementioned in the first point, you'll not have the leeway to waste time in the gym and this will result in you attempting to be a lot more productive with the effort you invest on these given days as you will learn to focus on the things that truly matter and produce results.
I've written more on the subject of Training Efficiency here.
Your Training Intensity will Increase
This is a salient point: if your time in the gym will increase and productivity increases, then you can wager that your intensity will follow suit which is always a good thing. It's difficult not to be more intense when you have less time to achieve your goals; yet in this special case, it's actually a beneficial factor that we're doing something less frequently, albeit in a more efficient manner. Being able to hit the weight room full of motivation, purpose and drive will undoubtedly help you lift heavier, faster and improve your overall performance drastically.
Results always depend on what you're not just willing to put in, but often what you're physically able to put in. Intensity is a crucial factor of success.
Recovery is superior
It can be difficult and often gruelling training on consecutive days for a lot of guys dependent on your recovery abilities. Often, your main compound lifts that you're focusing on will clash intensely and this can often be to the detriment of one of them. I believe this is an unnecessary sacrifice - if you train three days per week, you'll rarely encounter this problem. The feeling of being fresh and free of DOMS (most of the time) will leave you feeling a lot more prepared for battle everytime you step foot in the gym.
The potential for overtraining is decreased
Even though the volume of work you perform in three days per week may be the same as four days, it's telling that a lot of people can often go for prolonged periods of sustained progress of three days per week training as opposed to four where you're likely to stagnate, regress, or too frequently just have a higher potential for inferior training sessions. All these 'symptoms' scream "overtraining" to some extent; wouldn't it be easier if we were to all just begin training diligently three days per week and be patient with it? One of man's greatest problems is that he try's to take on too much, too soon. In training, this is certainly almost always the case with our egocentric personas constantly trying to integrate too much wasteful work for aesthetic reasons that often don't constitute anything productive at all towards success.
Your preparation will be better
This is a very important aspect of training and again, it's linked to that key concept of efficiency. When you have less opportunities to achieve something, you're a lot more focused on making sure you maximise those opportunities. This means a host of factors: your nutrition will be more meticulous and less rash; your time spent away from the gym will mean you have hunger and great desire to train; you will be more recuperated and fresh for each session - this is all very intertwined into what we've already discussed.
Being psychologically ready to attack the weight room is a huge component that is never overlooked by serious lifters.
The quality of your life will improve
I understand that training is all about sacrifices and it's a lifestyle. It still can be this way with training three days per week. However, what grinds my gears is the fact that some people propose that training has to take over your social life and you have to push other important values by the wayside to be successful: less nights out, dinners, family occasions are a no-no, etc. It's this incredulous reasoning that scares many people away and another reason why so many people struggle to find a balance.
I'd like to leave the article on this last point and say that training three days per week will usually give you a couple of days extra through the week to focus on other productive ventures - whether it's business, social opportunities with friends, family, etc. These are important factors that all need time and attention too and it's important we maintain a balance of perspective and devote time to other things that matter in our lives at the present moment as well before we disregard them as 'sacrifices'.
Three days per week has some great advantages over 4+ days, but I'm by no means claiming it's the be-all and end-all. There are many successful ways to achieve your goals, and hopefully this is another one that will help the equilibrium of your life restore some much needed balance and enjoyment. I hope this at least provided some enlightment and value to you, if anything.