When we do not exercise for a period of time, there are a multitude of physiological markers that reveal themselves indicating a reduction of fitness level.Our
The human body (whether we exercise or not) is a sensitive system and an amazing adaptive machine. Physiological changes like strength, fitness or endurance that are developed through training, dwindles as we stop working out or even reduce the effort/ load. Our body and brain’s primary motive is to keep us safe, alive and conserve as much energy as possible for our future survival. Since there is no external stimuli and stress, they body has no need to either maintain the muscle or to keep the energy reserves at the cellular level. Remember that our muscle consumes the highest amount of energy and nutrients for its maintenance, hence our body would prefer to lose the muscle if it is not used enough. Hence it also implies that having optimum muscle indicates a healthy state, longevity, better metabolism and energy balance in our body.
How quick a person de-conditions depends on factors like current fitness, age, diet and nutrition, lifestyle etc,. Experts say that two to eight months of not exercising at all will reduce our fitness level to as if we never exercised before. Speed, endurance, and strength can decrease by 25 to 30 percent within two to three weeks.
Many signs of deconditioning may not be visible to a naked eye, but factors like losing muscle and accumulating fat is common. A sizable decrease in muscle mass, capillary size, reduction in bone density; flexibility, overall blood flow and energy production are all side effects of not working out.
The Anaerobic system
Our body may hang onto strength gains (Anaerobic) longer than endurance(aerobic) gains, however stopping lifting weights will gradually lead to a loss of lean muscle mass, muscular strength, endurance, and neuromuscular training adaptations. As muscle fibers realize they don’t need to store energy, they will store less glycogen which leads to something called atrophy (or the shrinking of muscle fibers),
The Aerobic system
Aerobic and endurance fitness reduce a lot faster than muscle mass. It affects the performance factors.
Heart stroke volume (the amount of blood pumped out of the heart to the body) reduces, the size of mitochondria (the power plants within a cell, linked to fitness health) reduce by almost 50 percent, resting heart rate increases, cardiac output reduces, and VO2 max(the maximum volume of oxygen an athlete can use a gold standard of physical fitness) decreases about one percent a day, Lactate threshold(how hard and long we can work out until our muscles tell us to stop) begins to drop, endurance capability with is the ability to perform at higher intensities would fall down.
The Brain
Both aerobic (cardio) and anaerobic (strength training) training can give a boost to the neurotransmitter brain-derived neurotrophic factor (BDNF), which promotes neurogenesis (growth of new brain cells) and enhances connections between existing ones.
This makes exercise an important part of maintaining cognitive function, we may feel a little cloudy or not as ‘on’ after weeks of not working out.
The Sleep
Because exercise places both metabolic (or energetic) and mechanical stress on our muscle tissue, it can help promote good sleep,
A lack of exercise could lead to higher levels of energy in the body and reduce the need for deep sleep, which could lead to restlessness and disturbed sleep patterns.
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