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Mass Gain

The 3-Month Mass-Gain Plan

Filling out your frame with new muscle isn’t as hard as you might think. This 12-week, back-to-basics approach is all you need.

When it comes to gaining mass, everybody’s an expert. From the late-night infomercial guru to the chatty, grizzled gym veteran, it seems that everyone has a gimmick for getting huge. This pervasion of mass-gain punditry makes it difficult for the average lifter to zero in on what exactly needs to be done.

Luckily, there are a few universal truths that anyone can apply to elicit the gains he or she is looking for. We not only present three of them here, but our expert also used each of them to craft the accompanying mass-gain program, making it a proficient and practical method to gain an appreciable amount of new muscle over the next three months.

Truth No. 1: Muscles Grow With Big Lifts In The 8 to 12 Rep Range

Some people like to take a high-volume approach to muscle growth, insisting that challenging, high-rep sets flush the muscles with blood and trigger new growth. Other lifters are monogamous to big-weight lifts, clinging to the fact that to-the-brink sets will build the most muscle, even with very few reps. The middle ground, however, works for everyone — if it’s done right.

Jimmy Peña, MS, CSCS, a Los Angeles–based fitness expert, celebrity trainer and founder of PrayFit (, insists that the greatest gains in muscle come to those who stick to the most proven rep range for muscle growth — eight to 12 reps. “This is the range that is most known, physiologically and anecdotally, to elicit muscle growth,” he says.

Amazingly, there are still debates in fitness circles about which exercises should be used to build mass. Some argue that the greater the variety of exercises, the greater the stress placed on your musculature, the greater your growth in the long run.

“That’s ridiculous,” Peña says. “You can always add variety with single-joint moves, but if gaining mass is your primary goal, you need to stick to bread-and-butter, compound exercises like the bench press, squat and deadlift. Forcing multiple muscle groups to work in concert against progressively heavier resistance is the way to go, period.”

Applied Truth: In this program, you won’t ever perform a set with less than eight or more than 12 reps. Because this is the optimum rep range for hypertrophy — your main goal these 12 weeks — it makes no sense to deviate from it for novelty’s sake. Also, single-joint movements will be a rare find. Major lifts comprise the bulk of the exercises here.

Truth No. 2: Progression Is The Key To Growth 

Show us a person who has stopped growing and we’ll show you a person who has stopped challenging his or her body. Sure, sometimes a break is all that’s needed to get back into the growth zone, but more often than not, a plateau is because of a lack of creativity and ambition; once your body gets too accustomed to one routine, you can say goodbye to gains.

The best way to avoid that is to insist on progression and to build it into your plan. “Comfort is the worst thing that can happen to your physique, regardless of your goal,” Peña insists. “Remember, your body will only change to the degree at which it is stressed. Put another way, without throwing in new variables — in this case, more weight and varying rep protocols — your body will not respond well, if at all.”

Applied Truth: For the next three months, you’ll continually switch things up. Each month, you’ll handle progressively heavier weight loads in more challenging rep schemes (still within the eight to 12 window) to confuse your muscles and spur new growth.

Truth No. 3: Training To Failure (And Beyond) Is Required

One of the most misguided gym practices is stopping a set at a certain number when you clearly had more in the tank. Almost every time you see a prescribed rep range, in this magazine or elsewhere, the goal is to hit failure at that number. Failure is the point at which you can no longer perform reps with good form on your own. So if you bang out 12 reps when you could have done 15 or 16, you’re missing out on a slew of anabolic benefits.

“The key for any set that is based on a particular rep or rep range is to select a weight that causes you to fail at that particular rep,” Peña says. “Weight selection is of paramount importance to this program and just about any other. Hitting failure at these rep ranges triggers the pathways in your body where growth occurs. Going with a weight where you can complete more than 12 reps will instead move you more into the endurance-building zone.”

You can also get additional hormonal benefits by adding key intensity techniques to your sets. Extending sets by lowering the weight and continuing to perform reps after initial muscle failure, also known as drop setting, is one easy way to squeeze even more growth-inducing intensity into your workouts. Another way to build mass fast is by taking short, calculated breaks to take advantage of your body’s rapidly replenishing, explosive-energy stores so you can continue for a few more reps. This is known as rest-pause training. Variations on both techniques will be used in this program.

Training to failure, and beyond, causes additional damage within the muscle bellies which, when paired with proper nutrition, is the ideal environment for exponential growth.

Applied Truth: While you will be striving to reach muscle failure with each set in this program, you will add some intensity boosters in the second and third phases that are designed to help you take your muscles beyond failure.

Plan of Attack

Now that you understand the underpinnings of the program, here’s more detail on how you’ll be spending the next 12 weeks in the gym. In Phase 1 (weeks one to four), you’ll lay the foundation for future size gains. “In this phase, you’ll select your 12 rep max for your base line working weight,” Peña says. “After your first set of 12, you’ll rest no more than one to two minutes, then perform another two sets with that same weight, achieving no more than 12 but shooting for at least 10 on the second set and eight on the third set.”

In Phase 2 (weeks five to eight), you’’ll bring on more poundage. “This month, you’ll go a little heavier, selecting your 10 rep max, right in the middle of the magic growth range,” Peña explains. “You’ll do your first set so that you fail at 10. After your first set, you’ll be noticeably fatigued, but your second set is another 10 rep-max set. This means you will probably need to drop the weight slightly to achieve another 10 reps on each of the next two sets. Remember, the key is to fail at 10 reps. If you can do more, you went too light. If you can’t quite reach 10, you need to lower the weight a bit.”

Finally, in Phase 3 (weeks nine to 12), you’ll put your expanding muscles to maximum use. “Keeping with the theme of progression, your eight rep max will serve as your base weight,” Peña says. “And as you’ll see, we have you going for 10 and 12 reps after your initial set of eight. You might be asking how it’s possible to get 10 or 12 reps using a weight that causes you to fail at eight. The answer is you won’t, technically. When you get to eight on your second set, we want you to rest for roughly 15 seconds, then do another two reps to get you to 10 total. And on your third set, we want you to rest for 30 seconds before attempting an additional four reps to get you to 12 reps. It’s not necessarily a true rest-pause set, but the mentality is identical. You rest long enough for your explosive energy stores to replenish, then perform more repetitions, paving the way for more growth.”

One more note to keep in mind: These protocols will not apply to abs, which you will instead train twice per week at a standard rep range for all 12 weeks. Because you’re focused on getting bigger, you just want to keep your abs conditioned, but save the hardcore ab work for your get-lean plan.

Now, before you begin, one more truth to mention: Any training program is only as good as the effort you’re willing to put in. We assume you want to pack on impressive muscle gains and are willing to put in the intense work required — now it’s your turn to prove us right.

The Three-Month Mass-Gain Program

DAY 3: Rest