When our ancestors came down from the trees to adopt bipedalism, it was not just for a leisurely walk as we would in the park at Candos.
In those days the axiom was: run for dear life or go after the prey for survival’s sake. In fact some authorities believe that we started jogging and running first, and walking came later.
This gave the spur to our bodies to change anatomically. Gradually we acquired a flatter face, smaller teeth, shorter snout, longer neck and more powerful buttock muscles, coupled by more sophisticated feet arches. Our skull bulged backwards, and we sort of beat gravity to perfect our upright position. “We are very confident that strong selection for running, which came at the expense of the historical ability to live in trees, was the origin of the modern human body form,” says University of Utah biologist Dennis Bramble.
How many times have we not watched with glee as our children reinvent that upright posture at the age of one, as they learn to crawl, grasping table and chairs to stand and make the most hesitating first steps unaided – prompted by the stuttering raucousness and encouragement of the elders. These tots remind us of our own childhood days of struggle, hesitation and fear of falling as we raised our head, chest and whole body into that wonderful vertical posture. Maybe we did feel the same thrill that we now see on the faces of these growing, smiling kids. They are out to explore the environment, to explore and imitate the mobile agents: their parents.
Soon enough they learned how to adapt their musculo-skeletal apparatus, which at immaturity dictated their wide, hesitating cumbersome gait and limb movements; that milestone development would soon be incorporated into the subconscious, and walking would become a normal routine of everyday life. They had, in a few months, mastered what the ancestors accomplished only after thousands of years! Ontogeny recapitulates phylogeny, the saying goes. And unfortunate are those parents who discover that their infants have muscular dystrophy and would have to struggle in vain to stand and walk.
As adults we now find pleasure in walking. To do so we unconsciously choose our itinerary – whether to go alone or to join other friends. What better entertainment than to walk and talk at the same time. In so doing we review yesterday’s news and the recent talk of the town, and update our social knowledge. Many of us having started solo may jump to the opportunity to tag along a newcomer’s ‘parcours’; in so doing we add some spice and company to an early morning outing — the best of it being oblivious of the distance being covered. Golfers often indulge in this routine.
The early birds do catch the early morning’s coolness and quietness, and enjoy the magic of the rising sun that announces the new day, thereby titillating ourselves into believing that we are the rare witness to the movement of time. Just as events and information structure our conception of time so, it seems, the relative movement of trees, houses, buildings on our path gives us a notion of distance, which notion darkness would baffle, making us less tired.
Similarly this sensation is appreciated as we jog or walk across cane fields; as the scenery is monotonous, we walk on and on with a silent mind. The sense of distance is restored as soon as dawn breaks and we start meandering through streets with a variety of landmarks. Going round and round on a circular track may not be to the taste of some of us, because we feel it as a set duty; and what is duty (like reducing abdominal fat) is anathema to our sense of relaxation and pleasure.
Many like the early trip: it reinvigorates us before tackling the coming problems of the day. But a few may not feel that comfortable, because a walk stimulates some endorphins secretions (opiods) in our body and steers us to the bed again, pulling us away from work. So we would like to have our daily walk after sunset (again to lose the sense of distance), and to supplement the failing hormones in our system. Going uphill may be a strain on our ageing cartilage and ligaments, but we do realize that walking uphill while maintaining the same horizontal ground gait is unwise. Our mind is still tuned to coordinate all muscles and joints to go level, but the latter go on feeling a dissonance as they meet an uphill task; we feel out of breath. However, if we meet the challenge by lifting our feet, knees and hip joints as if we are stepping up a stair, we discover, to our amazement, that the job becomes easier and less tiresome! It is personal experience.
Socializing with friends will help prolonging our life. However, it may prevent us from thinking. That’s where going solo scores better; it stimulates us to think of the unusual, of the original, things that we cannot do in the company of others. One feels alone and special in our own universe. And then one can take short cuts or beat the unbeaten path when one chooses, without any constraint.
It was a queer but thrilling sensation; our children’s minds were programmed to see trees as non-mobile agents; yet here they were moving and flying by as we went to a wedding by car; the environment rolled by through our head scan. Now as adults, as we trot along, let’s revert back to that childhood experience, let our visual field be another scan of the passing scenes. Keep sailing through that environment while telling ourselves that we are literally putting one foot ahead of the other, like Armstrong did on the moon; but we are happy to be doing it here on terra firma. And tell ourselves that our belly and toes are splitting the air ahead for us to step into the unknown, as we would in a maze. Could there be a surprise round the corner?
Yet what an exercise: we are coordinating our muscles, nerves, our skeletal and nervous system. The more they are exercised and synchronized the more fit we are, the healthier we feel. The longer we live too, because our heart also is put to test as the blood courses through our organism to irrigate every part of our body. Calories are being lost, and we leave some of our cholesterol and fat behind.
But if nature has not taken its toll yet, then we can jog along ; and as we jog Nature has endowed our brain with a certain mechanism to deal with the rapid change of visual environment. “The faster we move, the less time the brain has to take in environmental cues and to associate them with a location on our memorized spatial map. Our perception therefore has to keep pace with the speed of movement so that we remember the right way to go. Otherwise we end up at the copy machine instead of the coffee machine.”
Prof Stefan Remy of the German Centre for Neurodegenerative Diseases at University of Bonn gave new insight into the working of spatial memory, which is now known to be in the area called hippocampus of our brain. The rhythmic electrical activity of that hippocampus undergoes changes as we speed up our movement, which in turn sensitizes the brain to incoming sensory impressions. The professor believes that what happens in the mice may be true to human also. The hippocampus is itself connected to a small group of cells situated in the centre of the brain: “They gather information from sensory and locomotor systems, determine the speed of movement and transmit this information to the hippocampus. In this way, they tune the spatial memory systems for optimized processing of sensory stimuli during locomotion,” explains Remy.
He has also found that this new circuit between these cells and the hippocampus gives the start signal for locomotion and that they actively control its speed – a function previously thought to be the monopoly of our cerebral cortex.
Let’s take our daily 10,000 steps, to keep us fit and happy.
Dr Rajagopala Soondron