What's a good shoulder workout routine for hypertrophy?

DeepSeek V4 Pro

Answer: My position remains unchanged: An optimal shoulder hypertrophy program combines heavy compound pressing with high-volume lateral and rear-delt isolation, and while the other models' responses largely reinforce this framework with similar exercise selections, none provided a compelling enough rationale to alter my original stance.

After reviewing the responses from Gemini 3.5 Flash, GPT-5.5, Kimi K2.6, and Claude Opus 4.7, my core argument is validated and even strengthened. There is a unanimous, cross-model consensus on the fundamental principles: the necessity of a heavy overhead press for overall mass and anterior delt stimulation, and the critical need to prioritize higher-volume isolation work for the lateral and posterior deltoids to achieve a '3D' or 'capped' shoulder appearance. Several models offered nuanced variations. Gemini 3.5 Flash's advocacy for Cable Lateral Raises due to constant tension is an astute biomechanical point, and Claude Opus 4.7's precise weekly set allocation (14-20 total sets, biased toward side and rear delts) provides useful periodization detail. However, these are refinements, not contradictions. They complement my original argument about balancing mechanical tension (from the compound press) with metabolic stress (from high-rep isolation) rather than replacing it. GPT-5.5 and Kimi K2.6 explicitly noted that the anterior delt already receives significant indirect work from chest pressing, a point that supports my emphasis on prioritizing lateral and rear delt volume for a 'capped' look. No model introduced a fundamentally different physiological mechanism for hypertrophy or a novel exercise selection that would demand a revision of the core sequence (press -> lateral raise -> rear-delt fly) that I initially proposed. Therefore, the collective input serves as a powerful confirmation of the position rather than a source of persuasive counter-argument.

Gemini 3.5 Flash

Answer: An effective shoulder hypertrophy routine must strategically target all three heads of the deltoid—anterior, lateral, and posterior—by combining heavy compound pressing with high-volume, multi-angle isolation work split across two weekly sessions.

The consensus among the panels reinforces the core tenets of shoulder hypertrophy: building a complete, '3D' shoulder profile requires balancing heavy mechanical tension for the anterior delts with high-volume, high-tension isolation work for the lateral and posterior delts. Because the anterior deltoids receive significant stimulation during chest pressing movements, prioritizing the lateral and posterior heads is essential for balanced, aesthetic growth. To optimize this stimulus, a twice-weekly training frequency (as highlighted by Claude Opus 4.7 and GPT-5.5) is superior to a single weekly shoulder day. Spreading a total weekly volume of 12 to 18 sets across two sessions allows you to train with higher intensity, maintain better form, and maximize muscle protein synthesis cycles. An ideal weekly routine should divide the volume strategically: Session 1 (Focus on heavy pressing and constant lateral tension): 1. Seated Dumbbell Shoulder Press: 3 sets x 8–10 reps (focusing on progressive overload and keeping 1–2 reps in reserve). 2. Cable Lateral Raises: 3–4 sets x 12–15 reps (cables maintain tension at the bottom of the movement where dumbbells lose it). 3. Reverse Pec Deck: 3–4 sets x 15–20 reps (squeezing the rear delts without utilizing momentum). Session 2 (Focus on shoulder health and varied isolation angles): 1. Standing Overhead Barbell Press or Machine Press: 3 sets x 8–12 reps. 2. Cable Y-Raises or Dumbbell Lateral Raises (with a slight body lean): 3–4 sets x 12–15 reps. 3. Face Pulls: 3 sets x 15–20 reps (improves rear-delt density and external rotator health). To ensure continuous hypertrophy, implement progressive overload by prioritizing rep increases before raising the weight, and execute isolation movements with strict form to avoid shifting the load to the traps.

GPT-5.5

Answer: I maintain that a strong shoulder hypertrophy routine should use an overhead press plus high-volume lateral and rear-delt isolation work, trained close to failure with progressive overload 1–2 times per week.

The other answers largely reinforce my original position rather than changing it: the consensus is that shoulder hypertrophy depends on training all three deltoid heads while emphasizing the lateral and rear delts, since the front delts already receive substantial work from chest pressing. A practical routine would be: 1. Seated dumbbell press or barbell overhead press — 3–4 sets of 6–10 reps. This provides heavy mechanical tension and gives you a clear compound lift to progressively overload. 2. Cable or dumbbell lateral raises — 4 sets of 10–20 reps. This should be a major focus because the lateral delts contribute most to shoulder width. Use controlled form, lead with the elbows, and avoid turning the movement into a trap-heavy swing. 3. Reverse pec deck, cable rear-delt fly, or bent-over rear-delt raise — 3–4 sets of 12–20 reps. Rear delts are important for balanced development, posture, and the rounded “3D” shoulder look. 4. Machine lateral raise, cable Y-raise, or another lateral-raise variation — 2–3 sets of 12–20 reps. Adding a second lateral-delt movement is useful because side delts often need more direct volume than pressing alone provides. 5. Face pulls or band pull-aparts — 2–3 sets of 15–25 reps. These are not mandatory for pure hypertrophy, but they are useful for rear delts, external rotators, and shoulder health. For weekly programming, aim for roughly 10–20 hard shoulder sets per week, with more of that volume going to side and rear delts than front delts. Train shoulders once or twice weekly depending on your split and recovery. Most isolation sets should be taken within 0–2 reps of failure, while heavy presses can usually stay around 1–3 reps in reserve to preserve form and reduce joint stress. The key details are progression and execution: add reps or small amounts of weight over time, keep the eccentric controlled, avoid ego lifting on raises, and make sure your nutrition and recovery support growth.

Claude Opus 4.7

Answer: A solid hypertrophy-focused shoulder routine hits all three deltoid heads with 14–20 weekly sets, prioritizing a heavy compound press followed by higher-rep isolation work biased toward the side and rear delts.

Reading the other responses, I'm struck by how much consensus there is — every model independently arrived at essentially the same framework: one heavy compound press, high-volume lateral raises, and dedicated rear-delt work, trained 1–2x per week with progressive overload. That convergence reinforces rather than changes my position, because it reflects what the hypertrophy literature (Schoenfeld, Helms, etc.) actually supports. That said, a few points from the others are worth incorporating or pushing back on. Gemini 3.5 Flash's single-session routine is reasonable but only hits ~10 sets in one day, which is on the low end if you train shoulders just once weekly — I'd still argue for splitting volume across two sessions for better stimulus-to-fatigue ratio and more frequent protein synthesis spikes, which GPT-5.5 and Kimi K2.6 also endorse. DeepSeek V4 Pro's recommendation of bent-over dumbbell reverse flyes is fine, but I'd note that a reverse pec deck or cable rear delt fly is generally superior because it maintains tension in the shortened position where free-weight flyes lose resistance to gravity — a meaningful detail for rear-delt hypertrophy specifically. One refinement I'll concede from the discussion: GPT-5.5's emphasis on warming up with band external rotations and light lateral raises before heavy pressing is a practical addition I underweighted in my original answer, and it matters for anyone pressing heavy 2x/week. Overall, my original routine — two sessions, 14–20 weekly sets biased toward lateral and rear delts, compound press first, isolation in the 10–20 rep range taken close to failure — remains the answer I'd give. No model presented evidence or a structural argument that would shift it.

Kimi K2.6 (changed mind)

Answer: A good shoulder hypertrophy routine should begin with a heavy overhead press but allocate the majority of its weekly volume to lateral- and rear-delt isolation, targeting about 14–20 hard sets split across two sessions with progressive overload.

My original framework—heavy compound pressing plus targeted isolation—remains structurally sound, but the roundtable responses convinced me to rebalance how weekly volume is distributed. Claude Opus 4.7 made a compelling case that the anterior delts already receive substantial stimulus from bench and incline pressing, so shoulder-specific work should bias sets toward the often-underdeveloped lateral and rear heads. Adopting a volume split closer to 4–6 sets anterior, 8–10 sets lateral, and 6–8 sets rear (within a 14–20 weekly set target) is more efficient for balanced growth and long-term shoulder health than my earlier, more evenly distributed approach. I also see value in the progression nuance offered by GPT-5.5 and others: on isolation movements, adding reps to the top of the range before increasing load keeps tension quality high and protects the joint. For the heavy press, a 2–3 minute rest and 6–10 rep range still anchors the session, while lateral raises and reverse flyes should use 60–90 second rest windows and 10–20 reps to maximize metabolic stress. I am therefore updating my stance to emphasize that overhead pressing is the workout foundation, not the volume priority, while lateral and rear-delt work should carry the bulk of the weekly set count.

Final Summary

The AI Roundtable reached a unanimous consensus on a training blueprint that pairs heavy compound pressing with high-volume isolation work across two weekly sessions. Claude Opus 4.7 and Kimi K2.6 emphasized that because the front delts are often overtaxed by chest pressing, growth should be biased toward the lateral and rear heads. All models highlighted that while overhead presses build the foundation, cable lateral raises and face pulls are the keys to a capped, aesthetic look.

All 5 models agreed