# The Calculator

## Stroke/intensity

Choose a stroke and intensity

## Duration

How long did you swim for?

# Description

## Introduction

This calculator estimates calorie burn for a variety of swimming strokes and activities based on activity duration and your weight.

Calorie expenditure can be calculated for front crawl, breaststroke, backstroke, butterfly, sidestroke, synchronised swimming, and treading water. For some of the strokes and activities the calorie burn for different intensities is available.

Swimming is the go-to exercise for many athletes suffering injuries, as well as for those trying to lose weight. Since there is no impact stress involved, it's an excellent supplement or alternative to running and other sports for those who are limited in the volume they can achieve, but wish to still train their cardiovascular system.

# How It Works

## METs

This calculator uses METs to estimate calorie burn for swimming activities. MET is as acronym for Metabolic Equivalent of Task They're a way of calculating how much energy is required or used for various activities. A single MET is approximately the energy needed to sit down quietly, and METs for other activities are worked out by referring to this baseline. For example, swimming breaststroke at a moderate intensity requires roughly five times more energy than sitting still relaxing. So this swimming intensity is equivalent to five METs. By taking the METs for an activity, the activity's duration, and the athlete's weight into account, an estimate of energy requirements can be calculated.

## METs and Calories (kcals)

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

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

For example, for a person weighing 80 kilograms, the number of Calories/kcals used for a 5 MET activity that lasts 45 minutes is:

`5 x 80 x .75 = 300 Calories`

## Swimming METs

To calculate the METs for various swimming strokes and pool activities, we use values from the 2011 Compendium of Physical Activities Reference List for Water Activities

The accuracy of the calculator is limited due to some of the terms used in the compendium being somewhat vague. For example, "recreational", "moderate", "general" or "competition".

Where there is more than one intensity listed in the compendium, we've tried to simplify things a little by just referring to "vigorous" and "moderate"

Vigorous: this is hard swimming. What you might do in a competition of in a harder training session.

Moderate: this includes swimming that isn't too challending. That won't necessarily be an easy swimming session. E.g. much training could consist of longer distances at relatively gentle intensities.

We've used typical names for the four standard strokes: front crawl, butterfly, breaststroke, and backstroke. Front crawl is also referred to as front stroke, American crawl and Australian crawl. Although freestyle is often used as a synonym for front crawl, it's actually a competition category where the swimmer is free to use whichever stroke they choose. There's also a sidestroke option.

Note the "leisurely" option. This doesn't refer to a specific stroke. Think of it as the general milling around you might do in a pool without actually swimming laps.

And if you're just interested in calorie burn while treading water, there are vigorous and moderate options for that. There's even a synchronised swimming option.

If your goal is the highest calorie burn per minute, then butterfly is your best option. However, breaststroke and backstroke are much easier to maintain for long periods, so are better suited for overall calorie burn.