00:00If you had to pick just one muscle that, when developed properly, has the biggest
00:07visual impact on your overall appearance, what muscle would you pick? Your back,
00:12quads, glutes? I think I'd pick the shoulders because when they're well
00:17developed they make everything else just look better. Your waist looks smaller
00:21and more tapered, your whole body takes on more of an X-frame, assuming you
00:24train legs as well, and everything else about your shape just seems to fit in
00:28better. So if your goal is to maximize the development of the shoulders, it's
00:31important to first consider their anatomy. The deltoid muscle is composed of three
00:35sets of distinct fibers. The anterior or front deltoid originates on the clavicle
00:39or collarbone and inserts on the humerus bone of the upper arm. The lateral or
00:44side deltoid originates on the top of the scapula or shoulder blade, also inserting
00:48on the humerus, and the posterior or rear deltoid inserts a little further back on
00:52the scapula, still inserting on the humerus. Because the main shoulder joint is a
00:56ball and socket joint, it has a very high degree of freedom, meaning the muscles
01:00that act on it can perform a bunch of different functions. But for this video
01:03we're going to focus on the primary joint actions. The anterior delt's primary
01:07function is shoulder flexion, or raising your arm up like in a front raise. The
01:11lateral delt performs primarily abduction, or lifting your arm out to the side like
01:15in a lateral raise. And the rear delt performs primarily horizontal shoulder
01:19abduction, or moving your arms apart horizontally like in a bent-over reverse fly.
01:23And while this video will focus primarily on the deltoid muscle, it's worth
01:28mentioning that the shoulder joint is also acted on by four muscles of the
01:31rotator cuff, which primarily act as shoulder stabilizers and internal and
01:35external rotators. So while they may not contribute much to the appearance of
01:39shoulder size and aesthetics, keeping the rotator cuff muscles strong can help
01:42promote training longevity. Simply adding internal and external cable
01:46rotations at the beginning of your workout is one way to improve the health of the
01:49shoulder joint. Multiple lines of research indicate that the deltoid is nearly a
01:52dead-even 50-50 split of type 1 or slow twitch and type 2 or fast twitch muscle
01:58fibers, which implies that, as usual, using a combination of high reps and low reps is
02:03the best way to optimize total muscle development. I think that a cornerstone
02:06exercise for any shoulder-focused routine is a press. According to American
02:10strength training coach and author Mark Ripito, the press is the most useful
02:13upper body exercise for sports conditioning. And if I could use only one
02:16exercise to build the shoulders, it'd probably be some sort of press. A 2010 study by
02:21Trebs et al. found that a flat or zero degree incline led to the worst anterior
02:25adult EMG activity when compared with the 28, 44, and 56 degree incline, each of which
02:31showed similar activation levels, although there was a trend for more
02:34activation with more incline. And this is in line with previous research from
02:37Barnett et al. showing that more shoulder activation was achieved with higher
02:40inclines in a later 2015 paper by Lauve et al. Based on this data as a whole, it
02:45appears that inclines between 28 to 90 degrees all activate the front deltoid
02:50to a large degree, but it can't be said that one angle is significantly better
02:53than the others. However, on my analysis, the trend seems to suggest that, all else
02:57equal, more incline equals more delt involvement. So what about dumbbells versus
03:02barbells? A 2013 study compared deltoid EMG activity with four variations of the
03:07shoulder press. Standing barbell press, standing dumbbell press, seated barbell press, and
03:11seated dumbbell press, using 80% of a predetermined one rep max for five reps on
03:16each exercise. Front delt activation was found to be higher with the dumbbells in
03:20both the standing press and the seated press, indicating that, as far as
03:23activation is concerned, dumbbells reign king. And while the lateral and rear delts
03:27are activated much less than the front delts in all of these vertical pressing
03:30movements, the standing dumbbell press did come out on top for both of these
03:33heads as well. It seems that the front delts can be trained optimally through the
03:37use of pressing alone, such as by including at least one horizontal press and one
03:41vertical press in your training routine. And front raises don't seem to be of much
03:45utility here, since not only are they often redundant, they also just aren't
03:48as good at activating the front delts as dumbbell shoulder presses, at least
03:52according to Sweeney 2014, which showed front raises to elicit only 57%
03:56activation relative to maximum voluntary contraction versus the 74% seen with
04:00dumbbell shoulder presses. Scientific fitness author Michael Gundel cited
04:04bodybuilders on average as having five times the front delt development of
04:08normal untrained folks, but only three times the side delts and only 10 to 15%
04:12more rear delt size. This indicates that there's the most room for improvement with
04:16side and rear delt components. Compared to the front delts, the side delts are
04:20activated much less in pressing movements. One 2013 paper showed the side
04:24delts to exhibit only about 20% muscle activity in the Smith machine shoulder
04:28press, compared to about 70% for the front delts. A later 2014 paper found the
04:32same basic result, the shoulder press was better at activating the front delts than the
04:36side delt. However, using dumbbells instead of the Smith machine seemed to get the
04:40side delts more involved, an effect that can probably be attributed to a
04:43stabilizing role of the side delts missing with use of the Smith machine. So
04:46while using a free weight press can lead to more side delt activation relative to a
04:50Smith machine press, it still isn't able to isolate them from the front delt and
04:53really develop that X-frame appearance. For this, I think exercises that train
04:57shoulder abduction directly are needed. That 2013 study by Button et al found the top
05:03three heavy hitters for lateral delts to be the dumbbell lateral raise, cable
05:06lateral raise, and reverse pecto. Biomechanically speaking, internal rotation of
05:11the shoulder should lead to more lateral delt involvement on lateral raises because
05:14of fiber orientation and line of pull, a contention supported by Bohek, Barron's, and
05:18Buskey's EMG data. However, many experts suggest that internally rotating or
05:22pointing the pinkies up increases shoulder impingement and injury risk. So if you
05:26want to play it safe or have a history of shoulder problems, the slight increase in
05:30activation from this pinkies up cue may not be worth the potential risk it
05:34presents. But as a single example, I've been using this cue for 11 years now and
05:37haven't run into any issues personally. Stopping the raise at or just below
05:41shoulder height and keeping the scapula retracted seems to be protective in my
05:45experience. One potential benefit of using cables over dumbbells is the more
05:48constant resistance curve. Dumbbells reach peak torque at the top end of the
05:52range of motion and virtually no tension is on the delt at the bottom of the range.
05:55Using cables ensures tension throughout the entire range of motion, and since some
05:59research shows that leaning away into the direction of the raise takes emphasis
06:03away from the supraspinatus and places it onto the side delt, my favorite
06:06variation currently is the lean away between the legs cable lateral raise.
06:10Another effective exercise for side delt stimulation is the upright row. A 2013
06:14study by McAllister et al. compared three different grip widths and found that a
06:18wide grip led to greater side delt EMG activity than a close or shoulder width grip.
06:22And for what it's worth, the wider grip also led to more rear delt and trap
06:25activation as well. However, since improper technique on an upright row has
06:29been linked to shoulder impingement, the authors of this study recommend keeping
06:32elbow elevation below shoulder height to minimize injury risk. I personally find
06:35that using a rope allows for more freedom at the shoulder joint in a more
06:38comfortable end position. I also cue myself to pull the rope apart as I row,
06:42which, in my experience, turns on the side delts more than simply rowing
06:46straight up. And finally, that brings us to the oft neglected rear delts, a muscle
06:50important not only for a balanced looking posterior, but also for postural and
06:53shoulder health generally. But Natal found that the rear delts were nearly
06:56silent in shoulder presses, and other data suggests they barely contract in the
07:00bench press, push-up, and other pressing movements. And according to EMG expert
07:04Brett Contreras, quote, isolation exercises for the rear delts kick the
07:08shit out of compound movements. Back to Button Natal. The reverse pec deck,
07:12incline lat pull-down, and seated row were the big three for the rear delts. But
07:15it's worth noting that three studies from Frank, Button, and Schoenfeld all
07:19independently showed the reverse pec deck to elicit about 90% EMG activity for the
07:24rear delts. Interestingly, a 2013 study by Schoenfeld et al found that a neutral or
07:29palms facing each other hand position increased mean activity of the rear delts.
07:33However, co-author Brett Contreras later commented that some subjects saw greater
07:36activation with the pronated or palms down grip, implying that you should play
07:40around with both and see what hand position feels best for you and your
07:43rear delts. And while data is limited, it's likely that other similar horizontal
07:48abduction-based exercises, like reverse flies and reverse cable crossovers, would also
07:52highly recruit the rear delts. Exercises like rows are also effective, but since
07:56the traps can take over, including isolation movements on days you train
07:59shoulders or back, is the best way to optimize their development. Volume expert
08:03Dr. Mike Isertel suggests that front delt isolation work isn't required to make
08:07progress since horizontal and incline or vertical pressing is sufficient. For both
08:11side and rear delts, eight weekly sets of isolation work per week stands as a
08:15minimum for progress, with double that, or 16 to 22 weekly sets, being a pretty
08:19optimal place for progress for most intermediate to advanced trainees. Just
08:23keep in mind the caveat that many, quote, isolation exercises target both the
08:27side and rear delts, and would count as a set for both under this scheme. Training
08:30the shoulders at least two times per week is supported by the most recent
08:33literature on training frequency. However, my experience working in the field
08:37suggests that isolation work for the side and rear delts can be performed as
08:40frequently as four to five times per week, especially if they're lagging behind
08:43other body parts without recovery issues. Recommendations for training volume and
08:47frequency for both men and women will depend on your level of advancement and
08:51are made in my shoulder hypertrophy programs. So if you take these training
08:55principles and apply them to an already sound fundamental training philosophy
08:58centered around consistency and progressive overload, a pair of 3D delts are
09:02there for you waiting to be built.
09:05What's going on everyone? So don't click out of the video just yet. I have a few
09:09important things I want to touch on. First is that I released my shoulder
09:12hypertrophy program for both men and women on my website today, and the main
09:15difference between the two is that the women's program has less of an emphasis
09:19on the traps, whereas the men's program has some carryover in the exercise
09:23selection between the traps and the shoulders, and that's just based on the
09:26fact that in my experience women tend not to want to build their traps as much
09:29as the delts. And the other differences are basically just physiological ones that I
09:33touched on in my sex differences science explained video. And if you're
09:36familiar with my body parts specialization programs, then you know that
09:39these are better thought of as training manuals and not just training
09:42programs. So this really has everything you could ever want to know about the
09:46shoulders in one place. It does have a complete eight-week training program, but
09:50also all the scientific information to do with periodization, progression schemes,
09:53every exercise that's included in the program is given a full defense for why
09:57it's there, complete with all the scientific references. You can get that for
10:00$19.99 on my website for the first week of launch, and after that it'll go up to
10:04$24.99. And also guys, I did release a footnote to this video that explores some
10:08topics that I just didn't have the chance to in this one. It digs a little bit deeper, and I'd really
10:12appreciate your guys' participation on that video. Please go check that one out.
10:15Until next time, thank you guys so much for watching, and I'll see you in the next one.
Comments