The MET concept represents a simple, practical, and easily understood procedure for expressing the energy cost of physical activities as a multiple of the resting metabolic rate. The cells in your muscles use oxygen to help create the energy needed to move your muscles. One MET is approximately 3.5 milliliters of oxygen consumed per kilogram (kg) of body weight per minute.

*Calories burned in one hour= METs x Weight (in Kg)*. For example: If your weight is 70 kg and running 12kmph (means with a pace of 5 min/km) your MET value is about 11.5 from Table.And Calorie Expenditure = 11,5 x 70= 805 calorie

Energy expenditure may differ from person to person based on several factors, including age and fitness level. For example, a young athlete who exercises daily won’t need to expend the same amount of energy during a brisk walk as an older, sedentary person.

Table 1: MET-Values

HEADING | ACTIVITIES | METs |

walking | bird watching, slow walk | 2,5 |

walking | walking the dog | 3,0 |

walking | walking, 4 kmph -level, firm surface | 3,0 |

running | Running, 6,4 kmph-9,4 min/km | 6,0 |

running | running, 8 kmph-7.5 min/km | 8,3 |

running | running, 9,6 kmph-6,3 min/km | 9,8 |

running | running, 10,7 kmph-5,6 min/km | 10,5 |

running | running, 11,2 kmph-5,4 min/km | 11,0 |

running | running, 12,0 kmph-5 min/km | 11,5 |

running | running, 12,8 kmph-4,7 min/km | 11,8 |

running | running, 13,8 kmph-4,4 min/km | 12,3 |

*Note: You can download fullcompendium list from the site:*https://sites.google.com/site/compendiumofphysicalactivities/compendia

*Example:* Comparing two person want to loose weight and spend only half an hour for physical activities, five days a week. One prefer walking at speed of 4 kmph, and other can run at a speed of 12.8 kmph for half an hour. Both has the same weight: 80 kg.

Calorie Expenditure for half an hour:the walker = 3 x 0,5 x 80=120 calories and the runner = 11,8 x 0,5 x 80=472 calories

For one week-5 days exercise, annually calorie expenditures.

Table 2: Calorie Expenditure runner vs walker

| 30 minute | 5 days x30 min | 1 year, 52 weeks |

walker | 120 calorie | 600 calorie | 31.200 calorie |

runner | 472 calorie | 2.360 calorie | 122.720 calorie |

*It is well known that one kg of fat=7.700 calories. But according to the recent research: For one kg of fat =15.400 calories. Let’s take the worst case scenario for those who want to loose weight. For one year of activity of 5 days a week and 30 minutes per day the walker might loose 2 Kg versus the runner 8 Kg , 1 over 4.*

Of course these are straight mathematics formula and human does not fit the formulas one-to-one; but these calculation might give a rough idea.** **

According to the latest trend HIIT- High Intensity Interval Training, hill running type exercises even offer more benefit for the same amount of time spent.

But the trick here is that all those calorie expenditure versus weight lost is valid if only your other daily calorie expenditure be the same amount your calorie intake, so the numbers emanate from above calculation would be a bonus calorie expenditure which lead weight lost.

You may calculate your daily calorie expenditure from MET value times your weight for one hour activity or laziness, and your calorie intake from what you eat and diet-calorie list on internet for remaining 23 and half hours.

Everything hides in the numbers and maths. Very popular elemantary school math water tank problem: A water tank can be filled by tap A in 3 hours and by tap B in 5 hours. When the tank is full, it can be drained by tap C in 4 hours. if the tank is initially empty and all three pipes are open, how many hours will it take to fill up the tank?

Let’s change the famous pool problem in elementary school a little bit. A pool can be filled in “x-hours” with tap A and “in y-hours” with tap B alone; It can be emptied “in z-hours” with a C-tap located under the pool. If all three taps are opened at the same time while the pool is initially full, will the pool fill or empty? In what time frame?

If we accept a full pool of 1 unit and open all taps at the same time, the formula for the occupancy load of the pool after a certain period of time:

**Pool’s occupancy load = 1+ (1/t _{A}+1/t_{B})-1/t_{C}**

If the emptying time of the C-tap is 1 hour and the filling time of A and B alone is 2 hours, and everything else is kept constant, the occupancy state of the pool remains the same, which is 1. If the C tap is opened to discharge more water, that is, if the discharge time is shortened, or if the A and B-taps are throttled, that is, the filling time is prolonged, the pool starts to empty. If the opposite happens, the pool will overflow. Here, the A-tap represents our daily normal diet, the B-tap represents the snacks in between, and the C-tap represents calorie expenditure, such as exercise, jogging, etc.

Calorie intake is the number of calories you eat and drink each day, and calorie expenditure is your resting metabolic rate plus spending with any physical activity. If the calorie intake exceeds the calorie burning, the excess calories are deposited in your body as fat and body weight increases. If calorie intake is less than caloric expenditure, your body fat stores provide the necessary calories and weight loss occurs.

Of course, not every pool can be expected to fit exactly mathematical formulas presented here. Some may be leaking, the exact volume may be different from the supplied, algae, some rust and dirt may obstruct the flow of water, etc.

However, if we can consume more calories than we take in a certain period, just like in the pool problem, we are losing weight. Of course, this rate may occur at different rates depending on personal and genetic characteristics and metabolism.

So for example say if you want to lose 6 Kg: For the worst case which is “for one kg of fat =15.400 calories”, you need to 6×15.000=90.000 calorie deficit approximately. If you are planning 6 month for this, you should reach 500 calorie deficit per day; by reducing calorie intake, increasing expenditure, or both. A calorie deficit of 500 calories or more per day is a common initial goal for weight loss for adults.