Stretching is one of the most misunderstood elements of training. Almost everyone has an opinion about it. Some stretch before lifting. Some stretch after. Some stretch daily because they believe it will make their muscles longer — and therefore give them “more room” to grow.

I’ve had many conversations about this exact topic. People often ask me whether stretching will help them build bigger muscles or change their shape. One of the most common explanations I hear is this:

“If I stretch the muscle, I make it longer. If it’s longer, I have more space to fill with muscle.”

It sounds logical. It feels intuitive. But it is not how muscle growth actually works.

Muscle shape is genetically determined. The length of your muscle belly, your tendon insertion points, and the natural contour of your muscle are largely inherited. Stretching does not change where your muscle attaches to the bone. It does not alter your anatomical design. What it can change is tolerance to length and range of motion — not structural shape.

When people say an exercise “changed the shape” of their muscle, what usually happened is something different. The muscle simply developed more fully. It filled out its existing structure. Once more fibers hypertrophied, the muscle revealed its true shape — the one that was already there.

The change was development, not redesign.

This does not mean stretching has no value. It just means we need to understand its role correctly.

Static stretching can be helpful in specific contexts. For example, gentle static stretching before bed can relax the nervous system and reduce the feeling of tightness accumulated during the day. Light static stretching after training or before certain activities may also improve perceived mobility. However, aggressive static stretching immediately before heavy lifting is usually not ideal, as it can temporarily reduce force production.

Dynamic stretching before sports like tennis or pickleball serves a different purpose. It increases blood flow, improves joint lubrication, and prepares the muscles for fast force production. This is activation, not lengthening.

I once attended a yoga session focused on long-duration stretches. Even though I train regularly and move through full ranges under resistance, the prolonged holds where the instructor encouraged breathing deeply into the discomfort created a different type of stress. With every breath, you are told to “relax into the stretch,” and gradually push deeper. In that session, I felt a significant stretch through my shoulder — and days later, it turned into pain that required time off to recover.

That experience reinforced something important: stretching intensity, duration, and individual structure matter. Group sessions are often designed for a wide range of participants. While instructors may offer alternatives, they cannot fully customize every position for every person. Some individuals need modifications that go beyond what can realistically be delivered in a class setting. Without personalization, what is meant to improve mobility can sometimes create irritation instead.

Stretching can improve mobility when it addresses real movement limitations. But mobility is not the same as muscle growth. And growth is not the same as flexibility.

Confusing these goals is where most people go wrong.

Some research suggests that loaded stretch under tension may stimulate hypertrophy in certain conditions. But that is not the same as passive stretching on the floor.

Muscle fibers grow when they experience mechanical tension, sufficient load, and proper recovery. Passive stretching alone does not provide the level of mechanical stimulus required to build significant muscle mass.

The idea that stretching creates “space” for muscle growth misunderstands how hypertrophy works. Muscles do not expand because there is more room. They expand because the fibers adapt to tension.

If you want muscle growth, you need effective resistance training — not longer holds in a doorway stretch.

This is where I personally see a major difference.

When exercises are chosen based on biomechanics — specifically the 16 biomechanical factors — they allow the muscle to move through its full anatomical function safely and efficiently.

With BRIG20-style movements, the muscle is not only contracting. It is being loaded in a lengthened position under control, then taken through a full contraction with joint alignment optimized for safety.

This means you are strengthening the muscle while also training it through its usable range of motion.

You are not stretching passively.

You are expanding strength capacity across the muscle’s natural range.

That is a very different stimulus.

In my own experience, I do very little dedicated stretching. Occasionally, yes. But not as a daily ritual. Because the exercises themselves take the muscles through complete functional arcs under resistance, I maintain strong, controlled ranges of motion.

Many people have noticed this on the tennis and pickleball court. I am often reaching wide, striking balls from extended positions, maintaining balance and power without feeling unstable. That ability did not come from long static stretching sessions. It came from strengthening muscles properly through their full biomechanical function.

Strength through range creates usable flexibility.

There is a misconception that you must choose between being strong and being flexible. In reality, when exercises respect joint mechanics and muscle design, strength and mobility improve together.

The key is how the movement is structured.

If an exercise overloads joints in compromised angles, it may limit mobility over time. If an exercise follows anatomical lines of pull and keeps torque within safe parameters, it can enhance both strength and joint capacity.

This is also where we need to address something that is often visible in gyms but rarely discussed openly. Many lifters who base their training almost entirely on heavy compound exercises gradually lose range of motion over time. Not all of them — but a large percentage. And the reason is not that compound lifts are “bad.” The issue is imbalance.

Compound lifts heavily stimulate the dominant muscles involved in those movements — the primary movers that naturally contribute most to force production. But smaller stabilizers and secondary muscles often do not move through their full anatomical range during those exercises. If those smaller muscles are rarely trained directly or taken through their complete arcs of motion, imbalances in strength distribution can gradually appear. Over time, this may contribute to increased tone or tightness in certain tissues, which can reduce usable range of motion — particularly as muscle size increases and movement patterns become more reinforced.

You can observe this in many gyms. Individuals who lift heavy but neglect isolated or full-range work sometimes struggle with overhead mobility, shoulder rotation, hip internal rotation, or even simple extension patterns. This is not because compound exercises automatically make someone tight. It is because certain muscles are being strengthened repeatedly in partial roles while others are ignored.

When all muscles around a joint are trained intentionally — through full biomechanical function — strength and mobility reinforce each other. When training is limited to only the biggest lifts, mobility may slowly decline unless corrective or complementary work is included.

This is why exercise selection matters so much.

The same intensity can serve different purposes. With the right programming, resistance training can support endurance, hypertrophy, longevity, performance, or mobility. The tool is the same — the application changes.

Stretching has its place. But it is not a shortcut to muscle growth. It does not change muscle shape. It does not create anatomical space. And it does not replace intelligent resistance training.

Muscles respond to tension, physics, leverage, and recovery.

When you train them through their full natural function with well-designed movements, you strengthen them, challenge them, and improve their usable range simultaneously.

That is why I emphasize biomechanics over routine.

If you want to understand how these movements are structured and how the 16 biomechanical factors determine exercise efficiency, you can explore the BRIG20 program and see how these principles are applied in practice.

Strength and flexibility are not separate goals. They are outcomes of doing the right work the right way.

Written By Moe Larbi
 Founder of SmartTraining365 & Ratel Mentality
Sports Performance Coach
 Helping athletes and everyday lifters train smarter, safer, faster, and stronger under real-world conditions.