How much energy/calories do we burn during training and race participation?
In order to answer this simple yet complex question we need to know what a metabolic equivalent, (MET), is. This is the amount of energy that a person uses per minute during physical activity and is dependent on the person’s body weight, their fitness level, level of exertion and the duration of the activity.
Muscle cells use oxygen to help produce the energy to fuel muscle contractions. The more oxygen that you consume and burn both during and after physical activity the more calories you will burn. The human body expends approximately 5 calories of energy to consume 1 liter of oxygen. If you use more oxygen during physical activity then you will burn more calories or energy.
One MET is the resting metabolic rate (RMR) of an individual which is approximately 3.5 liters of oxygen consumed per kilogram of body weight per minute (mL/kg/min). This represents the amount of oxygen used while the human body is at rest. If an activity requires 4 METS then it is doing 4 times the amount of work as compared to when resting which will then require 4 times more oxygen and calories.
METS and MET-Minutes:
A metabolic equivalent, or MET, is a unit useful for describing the energy expenditure of a specific activity. A MET is the ratio of the rate of energy A well-known physiologic effect of physical activity is that it expends energy. expended during an activity to the rate of energy expended at rest. For example, 1 MET is the rate of energy expenditure while at rest. A 4 MET activity expends 4 times the energy used by the body at rest. If a person does a 4 MET activity for 30 minutes, he or she has done 4 x 30 = 120 MET-minutes (or 2.0 MET-hours) of physical activity. A person could also achieve 120 MET-minutes by doing an 8 MET activity for 15 minutes.
Two Methods of Assessing Aerobic Intensity
The intensity of aerobic physical activity can be defined in absolute or relative terms.
The Advisory Committee concluded that absolute moderate-intensity or vigorous-intensity physical activity is necessary for substantial health benefits, and it defined absolute aerobic intensity in terms of METs:
• Light-intensity activities are defined as 1.1 MET to 2.9 METs.
• Moderate-intensity activities are defined as 3.0 to 5.9 METs. Walking at 3.0 miles per hour requires 3.3 METs of energy expenditure and is therefore considered a moderate-intensity activity.
• Vigorous-intensity activities are defined as 6.0 METs or more. Running at 10 minutes per mile (6.0 mph) is a 10 MET activity and is therefore classified as vigorous intensity.
Intensity can also be defined relative to fitness, with the intensity expressed in terms of a percent of a person’s (1) maximal heart rate, (2) heart rate reserve, or (3) aerobic capacity reserve. The Advisory Committee regarded relative moderate intensity as 40 to 59 percent of aerobic capacity reserve (where 0 percent of reserve is resting and 100 percent of reserve is maximal effort). Relatively vigorous-intensity activity is 60 to 84 percent of reserve.
To better communicate the concept of relative intensity (or relative level of effort), the Guidelines adopted a simpler definition:
• Relatively moderate-intensity activity is a level of effort of 5 or 6 on a scale of 0 to 10, where 0 is the level of effort of sitting, and 10 is maximal effort.
• Relatively vigorous-intensity activity is a 7 or 8 on this scale. This simplification was endorsed by the American College of Sports Medicine and the American Heart Association in their recent guidelines for older adults.1 This approach does create a minor difference from the Advisory Committee Report definitions, however. A 5 or 6 on a 0 to 10 scale is essentially 45 percent to 64 percent of aerobic capacity reserve for moderate intensity. Similarly, a 7 or 8 on a 0 to 10 scale means 65 percent to 84 percent of reserve is the range for relatively vigorous-intensity activity.
Have you ever seen the term MET on a piece of exercise equipment and wondered what it meant? MET stands for metabolic equivalent, which is one way that exercise physiologists estimate how many calories are burned during physical activity. Having a basic understanding of METs and how to use them can help you determine the best physical activities to help your clients achieve their health and fitness goals.
We can use the following table to determine our average energy expenditure per minute during various types of running and is dependent on the speed at which we are running:
4 miles per hour = 6.4 kilometers per hour= 15 minute miles= 9.3minutes per kilometer =6METS
5 miles per hour= 8 kilometers per hour = 12 minute miles=7.5 3minutes per kilometer =8.3METS
6 miles per hour=9.7 kilometers per hour= 10 minute miles=6.2 3minutes per kilometer = 9.8METS
7 miles per hour= 11 kilometers per hour = 8.5 minute miles=5.23minutes per kilometer= 11METS
8 miles per hour= 13 kilometers per hour= 7.5minute miles=4.63minutes per kilometer= 11.8METS
9 miles per hour= 14.5 kilometers per hour= 6.5 minute miles=4 3minutes per kilometer =12.8METS
10 miles per hour= 16 kilometers per hour=6 minute miles=3.73minutes per kilometer=14.5METS
11 miles per hour=17.7 kilometers per hour= 5.5 minute miles=3.43minutes per kilometer=16METS
12 miles per hour= 19.3 kilometers per hour= 5 minute miles=3.13minutes per kilometer = 19METS
13 miles per hour=21 kilometers per hour= 4.3minute miles=2.73minutes per kilometer=19.8METS
Cross country = 9 METS
Marathon =13.3 METS
Running stairs up = 15 METS