How does our body function during physical activity

0
917

By Elias Abichacra (Phd)

Our body is a permanent playground between two contradictory biological processes: one is notorious for building and we call it the Anabolic process while the other takes an opposite stand because it destroys and is named the Catabolic process. As long as a human being is alive, these two processes continue to live together. This permanent biological action of construction and destruction activity happening in the human body is called Metabolism. Depending on which process dominates you have an appreciable modification of physical fitness and by extension health.
Our body at rest is governed by a physiological principle called Homeostasis which means internal body stability with its’ best indicator being the constant body temperature of our body fixed at 37, 2° Celsius. At rest each person has a fixed Rest Heart Beat (RHB) which depends on age, physical status and physical condition. The number of respirations is also regular and doesn’t vary. Everybody has a theoretical Maximum Heart Beat (MHB). There is a slight difference between male and female persons. The MHB for a female person is 226 – (minus) the age of that person. For the male person it is 220 – the age. So if you are 20 years old woman, your MHB 226-20 = 206 and if you are a man it is 220-20 = 200. This is a theoretical value which means that some people can be above or under these fixed results. Every year unfortunately we lose one heart beat. I don’t mean to provoke our Heavenly Father, but what about the MHB of Abraham and Mathusalem? Certainly a biological and physiological mystery!
Strangely, physical exercise has a positive effect only on the RHB that lowers especially if you practice endurance sports and exercises. The record RHB is detained by Miguel Indurain, a 5 times Tour de France winner, with an astounding 29 RHB per minute. Marathon runners, Triathlon athletes have the lowest RHB results. People with an increasing body weight with the percentage of body fat augmenting; see their RHB which increases. The difference between a person’s RHB and his MHB is called the Heart Beat Reserve. The lower the RHB, the bigger the reserve. People who have a low heart beat recuperate quickly after performing a physical activity. When this speed of recuperation is fast, it is a correct indicator of good health. On the contrary when the speed of recuperation is sluggish, the person is not fit to practice a physical activity safely. To know the RHB of a person, it is important to measure it just after waking up in the morning after a night sleep while lying and avoiding any type of movement. The person takes the measurement for 15 seconds and by multiplying it by 4 gets the RHB per minute. This measurement must be reproduced every morning for several days until a constant result is found. It is useful to know that the RHB varies when the position of the body changes. When a person sits or stands the value of the RHB evolves by increasing. That is why to speed up physical recuperation it is usually advised to adopt a lying position.
The number of heart beats per minute as well as the number of respirations at rest is constant. These values change instantly when a person performs a physical activity breaking the physiological status quo. The heart beat can reach its peak result if the exercise is strenuous. At the same time the number of respirations which is usually 10 to 12 per minute can easily double and sometimes reach 24 to 30 respirations per minute. The breathing which in normal times is inaudible gradually becomes clearly audible. This change in the heart and respiration activity means that muscles must be constantly provided through the circulating blood with Oxygen and energy nutriments in order to sustain physical activity.
When a person wants to start training on a regular basis it is advisable he/she knows his/her starting point. Simple physical tests exist that can give a good indication of one’s physical status. No need to go to a gym to measure the physical status because it can be done at home. The RHB is a simple test and a quite good indicator. Then you have the easy but controversial Body Mass Index (BMI). You have others that give you a quite good indication of the fitness level of a person. I shall develop each method in the forthcoming articles that can help each person willing to do a physical activity regularly practice safely.
Don’t forget health is wealth.

You can contact the writer on this e-mail address: elias.abichacra@yahoo.com