A 5’2″ 19 year old female weighing 100 pounds (which is WAY too small anyways but this is the example given)… needs 1,200 calories to just sit around all day and do nothing. This is how it’s broken down (scientifically)
-The heart needs 12% of the calories (144 cals)
-The kidney needs 12% of the calories (144 cals)
-The Liver needs 23% of the calories (276 cals)
-The brain needs 23% of the calories (276 cals)
-The skeletal muscle needs 30% of the calories (360 cals)
You should also think about calorie cycling. You see the human body adapts to our environment and to our lifestyle. So if you eat the same caloric intake each and every day, the body adapts. So you need to stay one step ahead of the body. On a cardio day, decrease your calories by 200, and the next day increase it by 200. Do this a couple of times per week, and hopefully you will avoid the dreaded plateau. Besides you are moving away from needing to focus on fat loss, now you should focus on keeping the muscle mass and growing it. At 5’5 and 17% body fat, your “weight” includes alot of lean muscle. So your BMI may not be accurate.
Muscle is called “active tissue” because it requires a lot of energy to maintain itself. In fact, every pound of new muscle you add to your body will burn about 60 calories per day. That can really add up. Look at the chart below:
The Fat Burning Effect of Muscle
| Pounds of New Muscle | Pounds of fat burned per month | Pounds of fat burned per year |
| 1 | 0.5 | 6 |
| 3 | 1.5 | 19 |
| 5 | 2.6 | 31 |
| 10 | 5.1 | 62 |
| 12 | 6.2 | 74 |
| 15 | 7.7 | 93 |
| 20 | 10.3 | 123 |
By adding just 10 pounds of muscle to your body, it will burn off 62 pounds of fat over the next year! And it will keep burning those extra calories year after year. That means that when you’ve lost the fat, you can eat a lot more and not gain back the fat. Also, with less fat and more muscle, your body will have the lean, toned, fit look that every man aspires to.
So by combining aerobics with strength training, you can transform your body in the shortest possible time, and keep it lean and muscular year round without starving yourself on a low-calorie diet.