You were outside doing a little gardening.  You planted a few new herbs, pulled weeds, spread fertilizer, and watered.   While digging in the soil and getting your hands dirty did you ever wonder how many calories you were burning?  We know that the types of physical activity —gardening vs. walking, for example, influence the number of calories burned.  Determining the specific number based on the activity can be accomplished in multiple ways, more on that below.

The Benefits of Physical Activity Beyond the Burn

The great thing about increasing your physical activity is the added benefits beyond the calorie burn.  Below are just a few examples.

  • Feel-good neurotransmitters, called endorphins, are released during physical activity boosting your mood and relieving stress. 
  • Movement can help to lessen the pain and stiffness associated with arthritis.
  • Strength Training can restore bone density that is often lost as people age, particularly in post-menopausal women. (See: Vivo – AgeWise Colorado)
  • Exercise has been shown to reduce cognitive decline—even to eliminate or significantly delay the onset of diseases of the brain.
  • Physical activity reduces the risk of dying from colon cancer, diabetes, and coronary heart disease.
  • Movement helps to maintain independence and reduces the risk of falling. (See: Nymbl Science – AgeWise Colorado

Looking to Lose Weight

To lose one pound of weight a week an individual needs to burn 3500 more calories a week than they consume.  That’s 500 calories a day.  You can burn 500 additional calories a day by changing your eating habits, being more active, or a combination of the two.  Knowing how many calories you burn during an activity can help you to set your daily target for the number of calories you will consume.  To determine your specific daily calorie targets and learn more about total energy expenditure, refer to our article Over 60 and Gaining Weight?  Here’s Why!

Determining Calories Burned

A simple way to obtain an estimate is to use a calorie burn rate calculator.  The one provided here— Calorie Burn Rate Calculator is from the University of Rochester Medical Center.  There are several others available on the web.  Typically, all that is required is to input your weight and then read the table to determine the number of calories burned for your activity.  As an example, for a 135 lb woman, general gardening is listed as burning 270 calories per hour or 135 calories in 30 minutes.  Use calculators like these to compare activities relative to each other rather than relying on absolute numbers.  Does 30 minutes of gardening or 30 minutes of walking burn more calories?  Use results within the same calculation method to make relative comparisons. 

If you want more precision in your calorie burn calculation, try using the formula below and multiplying it by the number of minutes you performed that activity.

Energy Expended (calories/minute) = 0.0175 x MET  x Weight (in Kilograms)

*To determine your weight in kilograms, divide your weight in pounds by 2.2.

Metabolic Equivalent of Task, or MET, are values that have been assigned to specific physical activities based on the amount of oxygen used during that activity.  A higher MET value correlates to more oxygen used during the activity.  Running has a higher MET value than walking.  There are over 800+ activities provided in the PROCON MET database.   The values in the PROCON MET resource are based on the intensity of the activity that you perform.

Here is an illustration using the formula.

A 65-year-old, 135-pound woman is doing some container gardening for 30 minutes.  How many calories did she burn?

  • First, we convert her weight into kilograms.  135 lbs ÷ 2.2 kg/lb = 61.4 kg
  • Next, we determine the MET value from the PROCON MET database and find the value is 2.3.
  • Now, we plug it into the formula and multiply it by the number of minutes for the activity or 30 minutes: 

0.0175 x 2.3 x 61.4 x 30 = 74 calories (rounded to the nearest whole number)

You may be wondering why the number of calories burned in the formula was not equivalent to the number of calories burned using the calculator.  The answer is simple.  The table associated with the calculator provided only one choice for gardening.  However, the PROCON MET database provided four different choices for MET values based on the intensity of the gardening effort with very detailed descriptions of what each effort entailed.  If you’re looking to be more precise with your calorie burned estimate, choosing the PROCON MET database will provide a larger and more detailed selection of activities.

Points to Remember

  • Remember, any movement is better than no movement.  Doing activities you enjoy to keep you moving is more important than picking them based on calories burned.
  • Think about the added benefits of physical activity beyond the burn to drive your motivation to move.
  • Using the tools to estimate calories burned is just that, an estimate.  There will be some variability in the results based on the MET values used in calculators versus the ones you might choose to input into the formula.  The most precise results will come from specifically choosing your MET value from the PROCON MET resource which will allow you to specifically choose your activity from a table of over 800+ activities.
  • Consider using the tools to compare activities to each other if you are trying to lose weight. 

Resources

Calorie Burn Rate Calculator | URMC.Rochester.edu.  (2022). 

CU Sports Medicine Estimating Energy Expenditure | The University of Colorado Denver (2004, December).

PROCON MET Database | ProCon.org. (2022, August 3). 

Participant Guide Burn More Calories Than You Take In | CDC.gov (2020, August 25). 

Physical Activity and Health: A Report of the Surgeon General for Older Adults | CDC.gov. (1999, November 17).

Physical Activity for Healthy Weight | CDC.gov. (2022, June 16). 

Stress Management | MayoClinic.org.  (2022, August 3). 

The Life-Changing Benefits of Exercise After 60 | ncoa.org.  (2021, August 30). 

By Gretchen Stevenson RN, BSN | August 16, 2022