I've been strength training now for over 20 years. I spent a good chunk of it in pursuit of a bodybuilder's physique, and accordingly for many years I dutifully followed the routines of professional bodybuilders presented in books and magazines. Maybe it was that I lacked the genetics; maybe it's because I refused to take steroids at all, much less the complex cocktails consumed by competitive bodybuilders; or maybe I just didn't work hard enough — though I sure tried my best. But the reality is that I never quite achieved the look I wanted. I tried it all: "HIT" training in the style of Dorian Yates and Mike Mentzer; volume training like Arnold Schwarzenegger; high reps, low reps, and everything in between; and, of course, I've tried just about every body part "split routine" you could imagine. And while I've certainly learned a lot and refined my training over the years, that conventional bodybuilding approach just never really worked for me.
A funny thing has happened, though. Now in my mid-thirties, I've been getting better and faster results than I ever did in my teens and twenties. I'm leaner, stronger, and growing faster than I had thought my body was capable of. How? By the realization, perhaps comically obvious in retrospect, that the routines of steroid-enhanced bodybuilders with exceptional muscle-building genetics aren't going to work for a natural guy who, in high school, weighed all of 130lbs. I've never been particularly strong or had a propensity for building muscle; I am, as they say, a "hardgainer". But I've been able to break out of that rut by breaking some of the many 'rules' that governed my training for so many years:
Rule #1: Don't train the same muscles multiple days in a row
The essence of a split routine is that you hit a muscle hard, then allow it to recover by training other muscle groups in subsequent days. So you train chest on Monday, then back on Tuesday, then legs on Wednesday, and so on. This way, the logic goes, the muscles you work have the chance to recover between workouts.
But training various muscles with higher frequency works, and works very well. Frequency has to be balanced with volume and intensity (more on that momentarily), but you're probably capable of more frequency than you think you are. There's a misguided belief that if you train chest on Monday, you shouldn't train any pushing movements — and definitely not horizontal, chest-driven movements — for at least a couple of days. But even if you're a little sore, higher frequency training forces your body to adapt more quickly. The soreness goes away, and you just get more strength and size faster.
Do this instead: I'm not advocating that you pulverize the same muscles day in and day out; rather, using a measured and controlled intensity, coupled with higher frequency, can in my experience produce better results than annihilating a muscle and then leaving it alone for several days. And speaking of not annihilating a muscle...
Rule #2: Train to failure
You've gotta make those muscles hurt! They've gotta burn! Squat until you can barely walk out of the gym! For a lot of guys, hobbling out of the gym after leg day is a badge of honor. How do you know you've had a great chest workout? When you can barely turn the steering wheel of your car on the way home! If it takes all your effort to lift your coffee mug to your face, then you know you've had a killer arm workout.
Repeated sets to failure aren't just unnecessary, they may actually be counterproductive. Repeatedly training to failure puts a lot metabolic and neurological stress on the body. It may hinder recovery by causing a degree of microscopic damage to muscle tissue that is difficult for natural athletes to rebound from.
Do this instead: Try training with a bit more restrained intensity; a few good hard sets, and you're done; you've sent the necessary signal to your muscles. Then get back in the gym and hit them again, so you're repeatedly and frequently sending the signal that the muscles need to get bigger and stronger. Taking some sets to failure is necessary, but don't try to push yourself beyond your limit every set.
Rule #3: More is better
Volume definitely correlates with results. But the idea that you have to do set after set, completely exhausting the target muscle group(s), may end up simply eating into your recovery more than it delivers any reliable strength and hypertrophy gains.
There's some research that indicates that the window for a productive training effect is relatively small, and thereafter the training effect tapers off in spectacular fashion. You may be eating into your neural and metabolic recovery with tons of sets, but in prolonged workouts each set becomes less productive — possibly dramatically so.
Do this instead: You should see a clear theme in these first three rules: instead of slaughtering a bodypart every 3-5 with high volume workouts full of sets to failure (and beyond), try utilizing fewer sets, measured intensity, and higher frequency. For example, I've found in my own training that I can squat for 3 heavy sets of 3 reps four or five days a week and still have energy to pour into Olympic lifts (which are lower-body dominant).
Rule #4: If you start a program, follow it through in its entirety
This might seem like a controversial idea; after all, if you don't follow a prescribed routine through, how can you know whether it works?
To me, there are obvious indications that a routine isn't working that can be spotted in the first two or three weeks. If you're not recovering between workouts, if you're constantly fatigued and/or losing strength, or if you don't feel challenged, then it might be time to make adjustments. Routines taken from the internet, from books and magazines, etc., are not written for you. They're just generalized routines that may work very well for some people and not work much at all for others.
Do this instead: Be your own expert. As Bruce Lee famously said, absorb what is useful. If something isn't working for you, don't keep wasting time on it. That doesn't mean you should abandon the concepts in your routine entirely, but make adjustments to intensity, volume, frequency, or exercise selection to better suit your unique goals and needs. Integrate strategies that have worked for you in the past and use them to create your own unique program.
Rule #5: Confuse your muscles
There's a popular idea that you have to be constantly varying the exercises, angles, reps, and volume of your workouts to "confuse" your muscles so that they never adapt to any particular stimuli. It's false. Varying exercises and repetition schemes is fine to a point — if for nothing else, to stave off monotony — but the repetition of workouts is vital to ensure progress. Consistent progress requires you to force your muscles to do more work. If you aren't repeating exercises, rep schemes, and workouts, you'll have no idea whether you're actually getting stronger. Changing the exercises is a common strategy to avoid a plateau, but it's not necessary addressing the weakness in the program; often, a simple period of de-loading can more than solve the problem.
Do this instead: Log your workouts, and aim to repeat them frequently. Even if you have a rotation of workouts and movements you employ, don't let yourself go for more than a couple of weeks before repeating a workout. If you're not making progress, use your log to determine where you're falling short.