# Walking Calorie Calculator

# Calorie Burn & Walking

## Introduction

This calculator predicts the calories burned by walking various distances at a variety of speeds for walkers of different weights.

Walking for exercise is very common. In addition to race walkers, hikers, and those using walking to lose weight, walking is used by many runners as an alternative or supplement to running. Its low-impact nature means it's particularly suitable when carrying an injury or a niggle, or just when a break is needed from running. It's also really useful for warming up, cooling down, and as an alternative to standing around while recovering between reps.

Those who walk a lot for work or other reasons may wish to take the energy expenditure into account when planning diet or meals and increase their intake of calories accordingly.

## Weight loss

Despite being a low-level aerobic activity, walking is an excellent way to lose weight. Its low-impact nature and the fact that no special skills or equipment are needed make it an ideal exercise for those wishing to burn extra calories.

If walking forms part of a weight-loss plan, then it's really useful to be able to estimate calorie burn so that adjustments to diet can be made, and a calorie deficit achieved. This is important not only so that you can ensure walking volume is high enough, but also so that any increases of decreases in food intake are appropriate.

As with all forms of exercise used to help weight loss, the best plan of action is to proceed slowly to ensure that health is maintained. Rapid weight loss can also have adverse effects on energy levels, muscle volume, strength, and performance.

## Weight gain

If you're trying to gain weight then it's important that any extra activity is accounted for so that extra calories can be taken in to compensate. People often don't take walking into account when considering overall exercise volume, but if you're doing significant amounts then it's really important to consider its impact.

## Weight maintenance

Those who are happy with their weight may find it useful to work out how many calories they are burning by walking each day so that they can adjust their diet accordingly.

## Fuelling

Since walking is a relatively gentle activity people tend not to see it necessary to prefuel before or refuel after a walk. However, for long walks it can be useful to do so. Walking has the benefit that it's easy to eat while on the go, or to stop for a short break and have a snack. Understanding the energy requirements of walking enables the walker to prepare for the activity in advance.

# Walking Calorie Burn Calculation

## METs

The predictions made by this calculator are based on METs, *Metabolic Equivalent of Task*. METs are a common method of determining
how much energy is expended by performing various activities. The activity type, the person's weight, and the activity's duration are all used to determine energy use.
A single MET is roughly the amount of energy used by sitting down and relaxing.
This baseline is used to work out the METs for other activities.
As an example, walking at 3 mph requires roughly 3.5 times as much energy than sitting down. Thus, walking at 3 mph is equivalent to 3.5 METs

## METs and Calories (kcals)

Conversion from METs to Calories (kcals) is achieved as follows:

```
````Calories/kcals = activity (METs) x weight (kilograms) x duration (hours)`

The number of Calories/kcals used for a 3.5 MET activity performed for 2 hours by a person weighing 80 kilograms is:

```
````3.5 x 2 x 80 = 560 calories`

## Walking METs

We make use of the 2011 Compendium of Physical Activities Reference List for Walking in order to calculate METs used for walking at different speeds.

Where METs are not available for a certain speed, we use linear interpolation to derive an appropriate MET value.

## Hill walking and Calories

The calculator allows you to estimate the effect of walking up and down hills on calorie burn. We also use the Compendium of Physical Activities to estimate the effects of hills on a walk.

Most walks are completed as a loop, in which case the overall uphill and downhill elevation will be equivalent. An obvious exception to this is when walking on a treadmill and the grade is set to a fixed uphill value for the entirety of the walk. Unless specified with the "consider uphills only" we assume that the overall uphill climb is equivalent to the overall downhill climb.

There is only one estimate of METs provided for downhill walking in the Compendium:

```
````Walking, 2.5 mph, downhill`

This value is derived from two studies. The first is research examining energy expenditure of hunter-gatherer-horticulturalists in Peru and for our purposes includes vague terms, such as "walking up forest paths" with no reference to speed to slope; the second is research investigating energy and nutrient intake and energy expenditure of New Guineans, and also includes ill-defined terms, such as "walking around", again with no reference to actual speeds or inclines.

Several values for uphill walking are provided, but these are also fairly vague and poorly-defined, or include a range of speeds and or grades. For example:

```
````Walking, 2.9 to 3.5 mph, uphill, 1 to 5% grade`

As such, we don't consider the Compendium provides enough detail in order to estimate the effect of hills on calorie requirements when walking.

However, the Load Carriage Decision Aid (LCDA) walking equation comes to our rescue. This is an equation developed by aggregating dat from 11 separate studies . The rather complex equation derived from this research is:

```
``````
EE = 1.44 + 1.94
```*S*^{0.43} + 0.24*S*^{4} + 0.34*SG*(1 - 1.05^{1 - 1.1G + 32})

where

`EE = Energy Expenditure in watts per kilogram`

`G = Grade, expressed as a percentage`

`S = speed in meters per second`

The results of this equation, energy expenditure, is expressed in watts per kilogram, and watts are measured as joules per second. So, we can find overall energy requirements by multiplying to weight in kilogramd and walk time in seconds:

```
````joules = EE x weight in kilos x walk time in seconds`

Then we have energy requirements in joules, so it's a simple conversion to kilojoules or kilocalories for an understandable measure of calorie use.

Plugging in real values to the equation reveals that the extra calorie burn from walking uphill is almost completely offset by the reduction in calories from walking downhill.

For example, if a 170 lb (77 kg) person walks 10 miles (16 km) at 3 miles per hour (4.8 kph) then according to this equation they will burn about 975 kilocalories (4080 kilojoules).

If we add an elevation gain of 1600 feet (488 meters), which would be quite a hilly walk, the equation determines that the uphill component adds 225 kcal (941 kjoules) to the estimate, but the downhill component removes 157 kcal (657 kjoules) from the walk. This means a net increase of just 68 kcal (285 kjoules).

Not much!

## Carrying a backpack while walking

Carrying extra weight when walking will have an impact on calories burned: the greater the weight, the greater the energy used. The calcualtor offers the option to add the weight of any load, and it's simply added to your body weight and included in the calculation.