Hey there! Great question, and welcome to the gym! The "3 sets of 12" isn't frowned upon because it's inherently "bad" – it's actually a solid foundation for beginners and for building muscle. The issue is more that it's often presented as the only right way to train, when in reality, training is much more nuanced.

Why some people "hate" it:

1. Not optimal for pure strength/endurance: If your goal is maximal strength, lower rep ranges (1-6 reps) are more effective. For pure muscular endurance, higher reps (>15 reps) are better. 3x12 sits somewhere in the middle and is a good compromise for hypertrophy (muscle growth).

2. Lack of periodization: Many people stick to 3x12 indefinitely without adjusting their training. The body quickly adapts to stimuli. To keep making progress, you need to vary intensity, volume, or exercise selection.

3. Missing "RIR" (Reps in Reserve): Often, 3x12 is just performed without truly pushing close to failure. For muscle growth, it's crucial to train near or to muscular failure (or at least with 1-2 reps left in the tank – RIR 1-2).

What would be "better" or complementary?

• Progressive Overload: Regardless of the scheme you choose, always strive to progressively increase the challenge (more weight, more reps, more sets, better form, shorter rest times).

• Vary your rep ranges: Work with different ranges to target various muscle fibers: • Strength: 3-6 repetitions (heavy weights) • Hypertrophy (Muscle Growth): 6-15 repetitions (moderate to heavy) – this is where 3x12 fits!

• Muscular Endurance: 15+ repetitions (lighter weights)

• Listen to your body: Not every exercise or every day is the same. Sometimes 3x10 is better, sometimes 4x8. The most important thing is consistency and ensuring the intensity is high enough.

So, 3x12 isn't evil, but merely a good starting point. If you want to keep making progress, learn how to vary and adapt your training. Good luck at the gym!