3 1.3 Measures of Physical Activity
Measuring physical activity and fitness is a vital step in better understanding one’s overall health. Various measurement strategies may be utilized when assessing your own level, or others’ level, of physical activity participation. Often, measurement strategies differ dependent upon whether the environment is field-based (i.e., sport performance) or research-based.
Several frequently used field-based assessment methods include:
- Intensity Rating
- Heart Rate
- Rating of Perceived Exertion (RPE)
- Energy Cost
- Step-Count Data.
Assessment methods commonly used in research include:
- Metabolic Equivalents (METs)
- Activity Monitor Data (i.e., Accelerometers)
Field-Based Physical Activity Assessment Methods
Intensity: Refers to work or effort exerted to perform activity or exercise. Relative intensity may be determined by focusing on heart rate and breathing patterns while engaging in activity. Intensity ratings are as follows: Sedentary, light intensity, moderate-intensity, vigorous intensity (Centers for Disease Control and Prevention, 2015a). Note: Absolute intensity is determined by metabolic equivalent (MET) methodology.
A common method of monitoring physical activity intensity is by calculating heart rate, and determining if the target heart rate zone has been reached Heart Rate: A common method of monitoring physical activity intensity is by calculating heart rate, and determining if the target heart rate zone has been reached.6 The equations below may be utilized to determine resting heart rate, maximum heart rate, and target heart rates for moderate-intensity and vigorous-intensity physical activity (Centers for Disease Control and Prevention, 2015c; American College of Sports Medicine, 2013).
Resting Heart Rate: The number of heart beats per minute (bpm) when the body is not engaged in physical activity. An individual may take their resting heart rate at the neck, wrist, or chest. The recommended location is to place the index and middle finger lightly on the radial pulse on the wrist. Count the number of heartbeats within sixty seconds, or count the number of heartbeats in thirty seconds and multiply this answer by two (Centers for Disease Control and Prevention, 2015c). For the most valid measurement of resting heart rate, it is advised the individuals take this measurement in the morning prior to getting out of bed.
Maximum Heart Rate: the age-related number of beats per minute of the heart when working at its maximum; usually estimated at 220 minus the individual’s age (Centers for Disease Control and Prevention, 2015c; American College of Sports Medicine, 2013).
Note: New Maximum Heart Rate formulas have been utilized in recent years. Several alternatives to the aforementioned formula are: 206 – (0.67 x individual’s age); 208 – (0.7 x individual’s age).
Heart Rate Reserve: the Karvonen Method of Heart Rate Reserve (HRR) is utilized to determine an individual’s target training heart rate by incorp