Running is by far one of the most energy demanding means of moving yourself from one point to another… which is a great thing if your intent is losing weight! However, I am always presented with the following questions about running when working with weight-loss clients:

1. How much should I run?

2. How fast should I be running?


3. How long will it take for me to lose the amount of body fat that I want to get rid of?

These are all great questions, but there is not one discrete answer for each that will help everyone accelerate their weight-loss goals. However, through understanding the biomechanics and physiology behind how your body works while you are running, you will be equipped with the knowhow on what needs to be personally accomplished in order to kick start some fat burn!

In order to make most out of your running we need to establish the concept of Metabolic Equivalents, or METs for short. A MET is a basic means of estimating one’s energy expenditure during various physical activities, and can be computed out in order to give an amount of Calories expended. The reason why we use METs over Calories is due to the fact that a MET derives an estimation of energy expenditure relative to a person’s mass, while as a Calorie is just a direct measure of energy.

One MET is typically considered the metabolic equivalency of resting or sitting around doing nothing, and obviously the METs go up as the intensity of what you’re doing increases. Here is an example of how you would figure out one’s energy expenditure while they were at rest (given that the person weighs 100 kg):

1 MET = 0.0175 kcal∙kg-1∙min-1


Energy Expenditure (kcal/min) = 0.0175 kcal∙kg-1∙min-1∙MET-1 x METs x body mass (kg)

Energy Expenditure (kcal/min) = 0.0175 kcal∙kg-1∙min-1∙MET-1 x 1 MET x 100 kg

Energy Expenditure = 1.75 kcal/min

Now we have to figure how much energy this same person would utilize while running. Most moderate intensity activities start off at a MET value of around 6, the same level as though our 100 kg person was running at a 4 mph speed.

Energy Expenditure (kcal/min) = 0.0175 kcal∙kg-1∙min-1∙MET-1 x 6 METs x 100 kg

Energy Expenditure = 10.5 kcal/min

In my experience, calculating one’s MET value has been the most accurate means to estimate a client’s energy expenditure throughout a training program. This concept has gone a long way since the MET’s introduction in the late 1980’s, and a ton of research has been poured into establishing how many METs are in every activity… so this is even useful for those who are not runners.

Also don’t worry if you’re not feel up to using your trusty old calculator, most fitness watches and bands are pre-programmed to figure out Calorie consumption off of more complex algorithms based on your weight and your heart rate.

However, figuring out how many calories you’ve expended is only one half of the work needed to be put into a successful weight-loss program. A properly maintained nutritional deficit is also needed to create or maintain weight-loss, and you may just eat yourself in circles if you don’t factor this into your weight-loss mission. Again, we have more math to do!

One pound of fat equals roughly 3500 kcals, and much of that extra weight we carry around our collective midsection is due to eating slightly more Calories than we expend each day. Now to clarify, were not talking about 3500 kcals in one day… we’re talking anywhere from 10 to 110 Calories or more a day in excessive Calories. This is how you’ve may have slowly accumulated that middle-age spread, over the span of 20 years! This is reversible, and there are tools to assist a much needed nutritional deficit.

Start with a food journal. Online, there are countless internet tools and apps that allow for you to track and monitor your nutritional intake. Find one that fits your lifestyle, either through ease of use or super accuracy! In order to lose at least one pound of fat per week, you should have a combined deficit of at least 500 kcals from both physical activity and from your diet. This is where your math skills come back into play!

how long does running take to lose weight2

Calculate your weekly running energy expenditure as well as your resting energy needs, then divide that by seven days. This is your daily energy need for one week or regular activity if your objective was to maintain your current weight.

Now subtract 500 kcals from your daily need, this computes that nutritional deficit required for your weight-loss. Here’s an example using our 100 kg friend again, suggesting that he runs at 7.5 METs for around 60 minutes a day and sits around loafing about for the rest:

Resting Energy Expenditure = 1.75 kcal/min x 1380 min/day = 2415 kcal/23hr

Energy Expenditure from Running = 787.5 kcal/hr

Total Energy Daily Expenditure = 3202.5 kcal/day

Total Energy Consumption for 1 lb/wk Weight-loss = 3202.5 kcal/day – 500 kcal/day = 2802.5 kcal/day

Viola! You just did what a fancy new fitness band does in seconds! Truth be told, it is ultimately easier to figure out your body’s Caloric expenditure through one of these wearable gadgets. However, it is best to understand how all of this actually works during your weight-loss program because you can buy all of the fitness gadgets, and have accounts with all of the fitness apps… but zero results without a solid follow through with adherence to a diet and regular exercise!

For more MET values for different running speeds and other activities, check out the Compendium of Physical Activities website at!

Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett Jr DR, Tudor-Locke C, Greer JL, Vezina J, Whitt-Glover MC, Leon AS. The Compendium of Physical Activities Tracking Guide. Healthy Lifestyles Research Center, College of Nursing & Health Innovation, Arizona State University. Retrieved [date] from the World Wide Web.

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