Why Exercise alone can’t result in weight reduction

We’ve been told that exercise is a means to augment a weight management program and help keep the weight off once someone has lost it.

Training at an intense exercise program to burn calories may not always be practical. Using too much weight, running too fast or choosing a group fitness class which is too advanced can lead to injury. Training too hard can also add additional stress the body can’t accommodate, if not corrected properly levels of Cortisol which will further defeat one’s fitness goals.Net result we may end up not getting the body form and composition that we are aiming for.

There are three components to your metabolic rate: physical activity, resting metabolic rate, and the thermic effect of food. Physical activity – whether is it purposeful exercise such as jogging, activities of daily living such as typing and folding laundry, or simply unconscious fidgeting – is the only component of the three that you have much control over. The greatest component is the resting metabolic rate (RMR). It is responsible for 60–75 percent of the total calories burned each day. The digestion, absorption and storage of food – called the thermic effect of food (TEF) – is the smallest component

  • Resting Metabolic Rate. Is the calories that we burn to make keep our bodies functionin Most of the calories spent each day are spent for breathing, circulation, maintaining  body temperature, moving compounds in and out of cells,. This is the  resting energy expenditure (REE), a clinical measure of the RMR. The REE depends upon many things.
    • Body composition. Lean body mass (LBM) is the greatest determinant of REE. It includes water, bone, skeletal muscles, and other organs such as the liver, brain and heart. These organs drive most of the REE. For example, the liver accounts for approximately 29 percent of the REE. Skeletal muscle at rest is a smaller portion of the REE, accounting for approximately 18 percent. Building muscle will then increase metabolic rate, but it is not the metabolic furnace many people believe it to be. To make a large difference in REE, an individual would need to gain quite a lot of skeletal muscle. More calories are likely burned in building and maintaining the muscle than from the muscle’s effect on the REE. In fact, the resting metabolic rate of athletes is only about 5 percent greater than non-athletes.
    • Body size. Generally, the greater the body’s surface area, the greater the metabolic rate.
    • Age. The REE is greatest during periods of growth such as infancy, toddlerhood and adolescence. REE declines two to three percent per decade after early adulthood. The typical loss of LBM with aging does not account for the full drop in energy expenditure.
    • At the same age and weight, men usually have a higher REE because of the difference in body composition. Men usually carry more muscle than women.
    • Other factors.

 

  • Thermic Effect of Food (TEF). It takes energy to process the food you eat. Digestion of the food and the absorption, metabolism and storage of the nutrients account for approximately 10 percent of the total energy expenditure. The composition of your meal determines its TEF.

 

  • protein has a greater TEF than carbohydrate, which have a greater TEF than fat. In other words, eating makes us lose weight, protein “wastes” more calories than eating carbohydrate or fat. Thus, by increasing the protein content without increasing its calorie content, one can burn a few extra calories. The effect is not large, however. It has been estimated that by manipulating the macronutrient content of the diet, can result in 10% increase in TEF

 

  • Physical Activity Exercise Activity Thermogenesis (EAT). This is the most variable component of the daily energy expenditure. For most people, it accounts for approximately one-quarter of their total energy expenditure. It may be as little as 10 percent, however, in someone extremely inactive or bedridden and as much as 50 percent in athletes or heavy laborers.Unlike the RMR, which is pphysical activityroportional to LBM, the calories  burned in exercise are based on r body weight. For example, if a 100-pound person and a 200-pound person took a walk at the same speed and covered the same distance, the heavier person would use twice as many calories as his lighter walking companion. Sports specialists and researchers estimate the calorie cost of exercise in metabolic equivalents (MET). The metabolic cost of sitting quietly is 1.0 MET and is approximately 1 kcal/kg/hr. Using this value, other physical activities are assigned MET levels according to their intensity. Thus, energy expended by physical activity can be expressed in multiples of 1 MET. For example, walking on level ground at 3.0 mph has a MET value of 3.3, meaning it burns 3.3 times the energy of sitting quietly.

Non-Exercise Activity Thermogenesis  (NEAT) While running, playing tennis, lifting weights and other planned exercise are big calorie burners, don’t underestimate the energy used for shifting and maintaining posture, wiggling foot, tapping  fingers, brushing  teeth and other non-exercise activities. In a small study, researchers reported that sedentary lean individuals are upright in activity 152 minutes more per day than sedentary obese individuals. Such non-exercise activities account for about 350 calories daily], about the same as three or four fun-size candy bars.

Conclusion

CICO is the paradigm for weight loss, but this equation is complicated and doesn’t work all the time, various factors are into play, these are the calories found in food which may or may not provide the exact calories inside the body, the best thing to reduce weight is to increase the BMR component of the Total Energy Expenditure, this together with the NEAT, TEF and EAT ( Exercise Activity Thermogenesis) will bring success in fat loss

 

Reference:

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