When the body isn't subjected to movements that are different from what it's used to, it begins to cry out for support. Why? It becomes rigid. While sports like swimming, cycling, or walking are very beneficial for the body, they lack one thing: flexibility.

The risk we face in "middle age"—according to the World Health Organization's new classification—is that by becoming physically rigid, we automatically become mentally rigid. One thing goes hand in hand with the other.

I resist "letting the old man in," as Clint Eastwood said at 90 years old in an interview that went viral. And one of the main doors through which said old man likes to enter is, precisely, that of rigidity. The alarm bells go off when, from one day to the next, you find that there are movements that seemed easy yesterday but are now difficult to perform.

That's why, after three years, that Monday morning I decided to resume yoga classes, hoping that my body would remember what I had once been able to do.

As the class was about to end, the teacher asked us to enter a posture to relax our bodies and minds. We were all looking for a comfortable position when I heard a classmate say out loud, "I just can't find peace." I instantly understood what she meant. A slight adjustment of the mat or cushion we were using was enough to restore peace to her body, mind, and soul.

When you find this peace in yoga postures, a slight smile appears, the brain calms, balance in the body emerges, and the forehead relaxes. The face of serenity reveals itself. There's no way to hide it. Every cell in the body feels it. That's life. If you are at peace, you generate peace in your cells and, like ripples in water, you spread it to those around you. "The rhythm of the body, the melody of the mind, and the harmony of the soul create the symphony of life," as B.K.S. Iyengar says in his book Light on Yoga.We need to listen to ourselves, it's a journey within.

Life itself seeks harmony, like plants seek sunlight. If one of these three elements that make us up (body, mind, and soul) is restless, uncomfortable, or uneasy, we simply don't find it—not at home, not in life, not at work, not with our partners, not in our relationships. Lack of harmony is a form of self-war, which, sooner or later, surfaces in the form of anger or illness. We don't realize that, through every decision or lack of it, we allow it to happen. And a life without peace is no life.

The questions we can ask ourselves to monitor ourselves are: "What gives me peace? Who do I feel at peace with? When do I feel at peace?" If we are consistent with the answers to these questions, they become the beacon for our journey. This peace doesn't come from the mind or the ego that pushes us to do or achieve under its favorite premise: "You are not enough." This other voice whispers from the heart, indifferent to what reason thinks, and its influence is felt in every cell of that microcosm that is the body, projecting itself into the macrocosm of the universe.

There are times when, just like in yoga practice, with a slight adjustment on the mat, a glance from the person you love, a hug, a word, a handshake, a call, is enough for the symphony of life to return and everything to flow and settle.

Ultimately, this is what we all seek: to be and feel peace, but to avoid letting the old in.