Exercise - Day 21

I was out of office for most of yesterday afternoon running errands here, there and everywhere so hitting my 10k step count for the day was easy and passed with no real effort.

So after work last night there was no real need for me to go out for a walk, or was there?

Sat on the bed reading my fitness app stats for the day i could see i had indeed hit 10,000 steps but my activity minutes were very low for the day, below the 30 minutes of light to moderate activity per day recommended by The American Heart Institution.

How does my app know that i have not completed enough activity minutes for the day? By measuring Metabolic Equivalents (METs)...

What are METs?

A MET is a unit representing the amount of oxygen used by the body during any physical activity, 1 MET is equal to the amount of oxygen used by the body whilst in a sedentary state of lying in bed and surviving for 1 hour, to calculate how many calories burned by 1 MET we have to go back to my blog Meals - Day 9 and calculate our Basel Metabolic Rate (BMR).

My BMR as i am right now is 2991.51 per day and to find my BMR per hour i divide that figure by 24 hours

2991.51/24 = BMR 124.65p/h

So with a sedentary MET of 1 the amount of calories i burn per hour being alive and doing not much else are 124.65 calories.

For me to work out my BMR per minute i divide BMR p/h by 60 minutes:

124.64/60 = BMR 2.08p/min

I now know i burn 2.08 calories per minute in a sedentary state.

So now i go about my daily business of getting dressed, brushing my teeth, commuting, working, walking etc i move out of sedentary and into categories such as:

Light intensity activities.
Moderate intensity activities.
Vigorous intensity activities.

Luckily for us Dr Bill Haskell from Stanford University in the USA devised a basic chart which shows the various METs and to which activity they are associated with:

Light intensity activities such as;
Sleeping: 0.9
Watching television: 1.0
Writing, desk work, typing: 1.8
Walking, 2.7km/h on level ground, strolling, very slow: 2.3
Walking, 4km/h: 2.9

Moderate intensity activities;
Bicycling, stationary, 50 watts, very light effort: 3.0
Walking, 4.8km/h: 3.0
Calisthenics, home exercise, light or moderate effort: 3.5
Walking, 5.5km/h: 3.6
Bicycling, 16km/h, leisure, to work as pleasure: 4.0
Bicycling, stationary, 100 watts, light effort: 5.5

Vigorous intensity activities;
Jogging, general: 7.0
Calisthenics (e.g. push ups, sit ups, pull ups, jumping jacks), heavy, vigorous effort: 8.0
Running jogging, in place: 8.0
Rope jumping: 10.0

There are many other categories from ironing clothes to mountaineering, gardening to deep sea diving, use a search engine and search for "The Compendium of Physical Activities Guide" for an extensive .pdf file available for download.

So how many calories am i burning when completing tasks or exercises on the activities guide? I multiply my BMR/min by the minutes i spend in the activity zones for example if i was to walk for 30 minutes at a consistent speed of 4.8km/h i would calculate my calorie burn as follows:

(2.08 BMR/min x 3.0 MET) x 30min = 187 calories burned per 30 minutes of walking.

Back to the matter in hand, my activity minutes, i could see i was 17 minutes short at 1800 hours last night, so i went out took a good 30 minute walk with Ryan, i even did a bit of running!!! (a very small bit mind!), i'll save that story for another day.