Why all the false claims about strength?
"Mobility" training is becoming more popular as many people want to get better at moving, improve their joint health, and become more flexible. On the internet, some strong opinions are appearing, with a few of the louder voices claiming that strength training by itself is the best way to become flexible. Strength training does indeed help with flexibility by increasing neuromuscular control and how much a joint can move. However, saying that everyone needs to lift weights to become flexible makes a complex topic seem too simple. Many things affect how flexible a person is, such as how well the nerves and muscles work together, the condition of the soft tissues and a person’s unique body structure. Rational flexibility training should take a more detailed and personal approach, focusing on fixing specific problems and movement habits instead of using the same method for everyone.
In particular, the phrases “You’re not stiff, you’re just weak” and “Strength is the key to flexibility” have gained popularity because they offer a direct solution to a widespread issue. A lot of people experience sensations of tightness and find themselves restricted and unable to move with ease. This message makes it seem like if you avoid traditional stretching, which requires time and patience, you can take a quicker route through strength training.
This idea is easy to sell because it reframes movement issues as a weakness that people believe they can solve through structured resistance exercise. With strength training you can easily measure your advancement through the number of reps you complete, sets you perform, or weights you lift. Exercises for strength development create a stronger sensation of effectiveness compared to stretching for long durations. People experience active problem resolution instead of remaining passive on the floor for 20 minutes.
This approach aligns well with current fitness trends that emphasise strength development along with measurable outcomes and productive exercise sessions. The idea resonates with people who understand that progress comes from hard work. The message instructs them to approach flexibility in the same manner. It makes static passive stretching appear outdated and ineffective compared to exercises such as deep lunges or Cossack squats which enhance both flexibility and strength.
The idea also feels like a shortcut. It offers a two-in-one solution: training routines that enable you to build strength while simultaneously improving your flexibility. People who do not have time or patience interpret this as permission to skip static passive stretching entirely because lifting weights or resistance exercises offer a smarter, more efficient solution.
The statement that “you’re not stiff, you’re just weak” does not hold up when we look more closely at how the human body works. Flexibility is not one simple thing. It includes your ability to move without help, your control of that movement, how stretchy your tissues are, and how your nervous system reacts. Strength training can help improve your ability to move with control, but it does not solve every part of flexibility. For example, a person might be “tight” entirely because of tension in their nerves or restrictions in their connective tissues, not because they are weak.
Seeing flexibility only as a strength issue is too simple. Static passive stretching, like lying in a stretch and letting gravity help, still matters. It helps restore the length of tissues and calms the nervous system. While moving with weight and control might be more useful in some cases, that does not mean we can skip specific stretching or flexibility work in others.
It also depends on the situation. A strength-based plan might work well for a powerlifter who needs to stay strong in certain positions while lifting heavy weights. But that same plan won’t always work for a dancer who needs a big range of motion, or for someone who sits all day and feels stiff from not moving enough. Different people have very different needs, and it is not helpful to give the same advice to everyone, especially if it’s only based on what top athletes do.
Finally, this idea often ignores the need to look at each person’s situation. People feel tight for different reasons, like how they sit or move each day, old injuries, scar tissue, or how their nervous system protects them. Just getting stronger will not fix all of these issues, and it could make things worse if done the wrong way. We always need to take a deeper look at how someone moves, their past injuries, and how they live, so we can make sure the plan helps instead of harms.
Nonsensical ideas spread partly because people use cherry-picked research and repeat what others say without question. Mobility influencers often pick studies that suit their message or misunderstand what the research actually says. For example, they might use a study that shows better movement after strength training to say that all stretching is useless. But they often ignore the details of the study, such as how it was done, who it involved, or what it was really testing. Studies that disagree with their message are often ignored or not mentioned at all.
Social media encourages strong and simple statements. The platform algorithms boost bold claims and short phrases like “stretching is useless” or “just lift through your full range” because these posts get more reactions and shares. More thoughtful discussions about how the nervous system works, how people move in different ways, or how bodies vary from person to person don’t get nearly as much attention. Influencers quickly learn that simple messages and strong opinions, even when they're contrary to the scientific research, attract more views, while more nuanced perspectives get ignored.
This creates a cycle of confirmation bias. Fitness coaches and their fans surround themselves with people who agree with them, follow pages that repeat their views, and engage with posts that support what they already believe. Over time, they hear fewer new ideas and start to think that other opinions are wrong or outdated. These echo chambers make their own beliefs feel even more right, and they become less open to evidence that challenges them.
Important details are often ignored. Strength is seen as the answer to all flexibility problems, not because it always works, but because it fits a strong and appealing story. Instead of thinking critically, people follow group opinions. Simple and one-sided claims are rewarded with more followers, more attention, and more respect.
Strength and flexibility are not enemies. Rather, they work well together. When used with care, strength training can help and even improve flexibility. Exercises that stretch muscles while they work, like slow Romanian deadlifts or deep split squats, can enhance dynamic active range of motion by teaching muscles to stay strong and long. This helps create so-called "useful" range (although that's a silly phrase), where the body feels safe and steady, lowering the risk of injury.
But strength does not solve every movement problem. Static passive flexibility, neural control, and joint structure all matter too. A person can be strong but still feel tight because of tissue limits, nervous system tension, or long-term posture habits. In those cases, static or moving stretches, breathing exercises, and hands-on treatment may work better to ease tightness or bring back range.
The best plan is not choosing one or the other but using both. Building strength through range gives control and safety, while stretching and other flexibility work help with other parts of movement. Together, they cover everything that can hold movement back. Training should fit each person’s needs and limits. A gymnast or dancer may need to increase static passive range, while a strength athlete may focus more on holding stable positions under load. An office worker with tight muscles may do best with movement drills, stretching, and light strength work. Flexibility training and strength training are tools, not strict rules. When used together, they support each other and lead to better, more adaptable movement, whether for sport, performance, or just feeling good in everyday life.
Yours in flexibility,
Dan