For many years now, scientists have been studying and trying to test and determine the limits of the human body, with particular focus on strength and endurance. While some researches have been directed at finding out what makes some individuals, particularly athletes, possess “superhuman” characteristics, the end goal of the researches is to understand human evolution and survival. Some of the subjects continually being investigated are related to:
Sustenance. How long can humans survive without food or water? While some will say that people with more fat or muscle mass will likely survive compared to those who are undernourished, any person, in general, can be expected to live for weeks without food. In fact, the so-called rule of threes says humans can survive without food for 3 weeks and water for 3 days. However, hydration is on a case-by-case basis. The answer to how long a human can survive without water really depends on how fast water is lost in the body. The faster the rate of water loss, the faster the damage to the body. Dehydration not only impairs organ function but also decreases the volume of blood, thereby making it thicker. As a consequence, blood pressure drops.
Lifting Loads. British weightlifter Andy Bolton holds the record for the heaviest dead lift at 457.5 kilograms from the floor to his thigh. Meanwhile, the record for an overhead lift is at 263.5 kg. While weightlifters, even those on steroids, may probably be able to lift weights close to or slightly beyond these weights, scientists at the University of Southern California in Los Angeles believe that the record for lifting deadweights is starting to plateau.
Speed. Jamaican athlete Usain Bolt, regarded as the fastest person ever timed, continues to wow the world by breaking his own records in athletics. While he has shown that he can outdo himself each time, scientists believe that humans are bound to reach their absolute speed limit.
Concentration. Human concentration begins to decline as the work day progresses. Not getting sleep also plays a big role in keeping the powers of concentration at an optimal, if not a functional, level.
While science has proven time and again that the human body sets a limit to what it can do, a school of thought says limits to physical and cognitive abilities are all in the mind. Having the notion that one’s body has limits is actually the principal limiting factor that prevents one from reaching his or her full potential. Several experiments performed by Psychologists Ulrich Weger and Stephen Loughnan seem to have proved this. In one experiment, hotel room attendants who cleaned an average of 15 rooms each day at 20-30 minutes per room were told that their activity is tantamount to doing exercise, say at the gym. Another group was not given this suggestion. After 4 weeks, the first group lost body fat and a significant drop in blood pressure while the condition of the attendants in the 2nd group did not change.
Meanwhile, researcher Antonella Pollo and colleagues experimented on the correlation between caffeine and lifting weights. They asked people to lift a certain weight before and after drinking high doses of caffeine. But the truth was, the liquids had no caffeine in them and the weights were reduced after the subjects drank the liquid. People associated the liquid with less fatigue and when they were asked to lift the original weight, they were able to do so with less strain.
Expecting that work will bring about health benefits, such as cleaning hotel rooms, and the “placebo effect” have been shown to change chemical reactions and neural synapses in the brain, resulting in physiological outcomes, such as weight loss or less fatigue as shown in the two experiments. Scientists believe that these are adaptations that helped humans evolve and survive by preparing human minds and bodies for the uncertain future environments. This is no different from any animal’s response, whether physically, mentally or physiologically, in the face of a predator, even before the predator is in sight.