Physical Activity, Physical Fitness and Mental Health
Assessment of Physical Activity
and Sedentary Behavior
Dr. Stijn De Baere
Prof. Dr. Johan Lefevre
KEY KNOWLEDGE /

What is a subjective, objective and criterion physical
activity assessment method?

What are the advantages and disadvantages of each
method?

When should I use a certain method?
BACKGROUND /
(Global health risks WHO;2009)
BACKGROUND /
Recognition of the crucial role of PA for health purposes
Increased interest in the (correct) assessment of PA:
• Research & health professionals
 Epidemiology
 Development and evaluation of interventions
 Clinical purposes
• Consumer-based self-monitoring
 Feedback
 Motivation & goal setting
PHYSICAL ACTIVITY /
PA is a multidimensional behavior: FITT-principle
-
Frequency :
Intensity :
Time :
Type :
# of sessions
physiological effort
duration of sessions
what type of activity?
+ Context: time & place, posture, social parameters
PA = complex behavior
Assessing PA is a challenging tasks
Why measuring physical activity and
sedentary behavior?
To measure is to know:
‘If you cannot measure it, you cannot improve it’
L. Kelvin, 1824-1907
WHY ? /
At the population level:
• To understand the dose-response relationship between
•
•
•
•
PA/SB and health outcomes
To identify current and changing activity levels within
populations
To monitor compliance with public health guidelines
To identify the biological, psychological and
environmental factors that influence PA/SB
To determine the effectiveness of interventions
WHY ? /
At the individual level:
• To identify current activity levels
• To detect change in an individual’s behavior
• Feedback, motivation and goal-setting
Physical (in)activity assessment
techniques
PA ASSESSMENT / overview
1. SUBJECTIVE METHODS
•
Questionnaires
•
Diaries
2. OBJECTIVE METHODS
•
Heart rate monitors
•
Pedometers
•
Acclerometers
•
GPS
•
Multisensor devices
3. CRITERION METHODS
•
Direct calorimetry
•
Indirect calorimetry
•
Doubly labeled water
•
Direct observation
PA ASSESSMENT / overview
1. SUBJECTIVE METHODS
•
Questionnaires
•
Diaries
2. OBJECTIVE METHODS
•
Heart rate monitors
•
Pedometers
•
Accelerometers
•
GPS
•
Multisensor devices
3. CRITERION METHODS
•
Direct calorimetry
•
Indirect calorimetry
•
Doubly labeled water
•
Direct observation
PA ASSESSMENT / overview
1. SUBJECTIVE METHODS
•
Questionnaires
•
Diaries
2. OBJECTIVE METHODS
•
Heart rate monitors
•
Pedometers
•
Acclerometers
•
GPS
•
Multisensor devices
3. CRITERION METHODS
•
Direct calorimetry
•
Indirect calorimetry
•
Doubly labeled water
•
Direct observation
SUBJECTIVE METHODS
SUBJECTIVE / types
Self-report techniques:
• Self-administered questionnaire
 IPAQ, Baecke, Pfaffenberger,…
• Interviewer-administered questionnaire
 Face-to-face, phone, Skype
• Proxy-report questionnaire
 e.g. parents on PA behavior of children
• Diaries
 Daily chronological recall of activity behavior
• PA logs
 Similar to diaries but less burdensome: checklist
SUBJECTIVE / pro’s & con’s
•
•
•
•
•
Inexpensive, allowing large sample sizes
Quantitative and qualitative information
Low participant burden
Can be administered quickly
Estimate EE trough Ainsworth Compendium
• Reliability and validity: recall of PA

Especially in youth and elderly
• Interpretation bias
• Social desirability bias
• Data processing: labour- and time-consuming

Implications for large-scale studies
SUBJECTIVE / evolution
Digital evolution:
- Computerized questionnaires:
No missing data, no coding error, no data entry, immediate
report, skip needless questions
- Electronic diaries
Real-time registration of activity type (no recall bias)
- Ecological momentary assessment
= answer on prompts on smartphone or PDA
 Context of activity behavior
- Environmental
- Social
- Emotional
-…
OBJECTIVE / overview
Established methods
Emerging methods

Topics
•
•
•
•
•
•
Definition
Placement
Outcome parameters
Mechanism
Research devices
Specific devices
Consumer devices
Pro’s & Con’s
OBJECTIVE METHODS:
established techniques
OBJECTIVE / heart rate
Heart rate provides a direct indicator of the physiological
response to PA
 Moderate to vigorous PA: linear relationship
between HR and oxygen consumption
 Lower intensities and rest: non-linear
= confounded by other factors: e.g. caffeine, stress,
smoking, temperature,…
Outcomes
• Heart rate bpm (average, min and max )
• EE (subject/group derived regression equations)
OBJECTIVE / heart rate
Placement
• Classic HR belt + watch
• Wrist-worn: optical sensors
(consumer devices)
OBJECTIVE / heart rate
Photoplethysmography (PPG)
OBJECTIVE / heart rate
Moov HR: Head sweatband with integrated photoplethysmography sensor
(consumer device)
OBJECTIVE / heart rate
Infrared sensor
OBJECTIVE / heart rate
•
•
•
•
Directly related to physiological response to PA
Lightweight and portable
Relatively cheap
Minute-by-minute data collection (time pattern)
• Confounding factors of HR - VO2 relationship
 temperature, humidity, hydratation, stress, age, gender, muscle mass
• Individual calibration of HR - VO2 relationship required
 Implications for large-scale studies
• Not suited for low intensity EE estimation
• Discomfort of chest strap
OBJECTIVE / pedometer
A pedometer or step counter records the number of steps taken.
Placement
•
•
•
•
Usually worn on belt or waistband
Midline of the thigh
Left or right (consistency!)
Also wrist, ankle or shoe
Outcomes
• # steps
• Distance (stride length)
• Calories (sum of EE per step)
OBJECTIVE / pedometer
Mechanims
• Spring-levered
Plastic lever arm
(e.g. Digiwalker)
Electric circuit
Spring
Battery
• Piezo-electric
Piezo element
External force
Electric voltage
(cut-off)
OBJECTIVE / pedometer
Research devices
Stepwatch
Digiwalker
OBJECTIVE / pedometer
Consumer devices
Fitbit Zip
Yamax Powerwalker
Pedometer apps
…
OBJECTIVE / pedometer
•
•
•
•
•
Simple and accurate
Inexpensive
Unobtrusive (low participant burden)
Extended periods of monitoring possible
10.000 steps guideline (goal setting)
• Only ambulatory activities
• Less accurate for distance
 constant stride length
• Less accurate for EE
 no distinction between walking/running/stair climbing
• Validity compromised in:
 obese, frail older individuals, gait abnormalities
• No information on activity pattern
OBJECTIVE / accelerometer
Accelerometers measure body movement in terms of
acceleration.
Placement
• Mostly on belt or waistband
• Recently: wrist-worn (less obstructive)
Outcomes
• Counts
 Product of amplitude and frequency of the acceleration
• Energy expenditure
 Linear regression equation using counts and personal data
• Intensity classification
 Intensity cut points for activity counts
• Steps
OBJECTIVE / accelerometer
Output:
Downloading the data to the computer
for data processing and analysis
OBJECTIVE / accelerometer
Mechanism
• Registration of acceleration on 1, 2 or 3 axis
• Piezo-electric sensors
 voltage proportional to acceleration
 filtering of raw signal
OBJECTIVE / accelerometer
Research devices
RT3 - Tritrac
ActiGraph
Actical
OBJECTIVE / accelerometer
Consumer devices
Polar Loop
Caloriscan
FitBit Flex 2
…
Moov
OBJECTIVE / accelerometers
• Accurate (counts)
• Information on patterns of PA:
 duration, intensity, frequency
• Minute-by-minute data
• Multiple days of monitoring possible
• Missed activities:
 upper body, load-carrying, cycling, water-based
•
•
•
•
More technical expertise
Wear vs non-wear
Different intensity cut-offs (generalization)
Underestimation at highest intensities
OBJECTIVE METHODS:
emerging techniques
OBJECTIVE / activPAL
Classification of periods of sitting/lying, standing and walking.
 Objective recording of sedentary behavior
 Inclinometer + uniaxial accelerometer
OBJECTIVE / activPAL
OBJECTIVE / posture
OBJECTIVE / GPS
Global positioning system and physical activity monitoring:
 Mostly consumer devices
 Focus on sports
 Combination with classic heart-rate belt
Outcomes
•
•
•
•
Speed
Distance
Altitude
Location (context)
OBJECTIVE / GPS
Emerging in physical activity research for contextual data.
 complex analysis
OBJECTIVE / GPS
Importance of up-to-date geographical information systems (GIS).
OBJECTIVE / GPS
• Promising tool for complementing other PA measures
• Relationship between environment and activity
 where does activity occur?
• Accuracy
• Loss of signal
• Quality of geographical information system
OBJECTIVE / multisensor
Integration of multiple sensors into one device.
Research Devices:
Actiheart
IDEEA
SenseWear
OBJECTIVE / actiheart
HR monitor + integrated accelerometer
Placement
Clip on to ECG electrodes on the chest
Outcomes:
o
o
o
o
Counts
HR
PAEE
Time spent in different
intensity categories
OBJECTIVE / actiheart
• Waterproof
• More precise estimate of PAEE
 Counters disadvantages of each method alone
• Relatively expensive
• Skin irritation
• Individual calibration needed
OBJECTIVE / sensewear
The device combines 3-axial accelerometry with different
physiological measures for the estimation of EE.
Placement
 Left upper arm over the triceps
Outcomes
• Energy expenditure
 PAL and calories
•
•
•
•
Intensity classification
Steps
Sleep
Activity classification
OBJECTIVE / sensewear
Mechanism
OBJECTIVE / sensewear
•
•
•
•
•
•
Location on body
24 h per day (also sleep)
Wear vs non-wear
Activity classification
Activity pattern
Non-ambulatory activities
•
•
•
•
Proprietary algorithms: issue in research
Water-based activities
Higher intensities (i.e. > 9 METs)
No longer produced …
OBJECTIVE / ideea
= Intelligent Device for Energy Expenditure and Activity
OBJECTIVE / ideea
5 small sensors (1 chest, 2 thigh, 2 feet) +
200g data collection device
Pattern recognition
 identification of 32 activities
Output:
• Type of activity
• Duration
• Estimated intensity
OBJECTIVE / ideea
• Very accurate for assessing activity mode,
duration and intensity
• Detailed PA measurement useful for clinical
applications (e.g. movement disorders)
• Expensive
• Limited memory (48h)
• Intrusive with 5 wired sensors
OBJECTIVE / multisensor
Recent consumer Devices:
Polar V800
FitBit Ionic
…
Jawbone UP3
OBJECTIVE / fitbit
OBJECTIVE / fitbit
OBJECTIVE / multisensor
Recent consumer Devices:
Polar V800
FitBit Ionic
Jawbone UP3
Integration of sensor outputs = biggest challenge
…
ALGORITHMS /
Translates the raw data of the different sensors into meaningful
PA outcomes.
Input
data
ALGORITHM
‘ BLACK BOX ’
PA
output
FUTURE: optimalisation of algorithms
 Pattern recognition: PA classification
(when to apply a certain algorithm = complex flow-chart)
 New modelling approaches
Important for research: open source algorithms
PAVLOK /
CRITERION METHODS
CRITERION / direct calorimetry
Measuring EE by measuring heat production or heat loss
CRITERION / direct calorimetry
• Accurate to quantify EE during rest and PA
•
•
•
•
Expensive
Time consuming: not for large-scale studies
Requires expertise
In most cases not feasible
CRITERION / indirect calorimetry
Measuring EE from O2 consumption and CO2 production
with a mouthpiece, facemask or canopy during rest or
exercise
CRITERION / indirect calorimetry
• Accurate and valid measurement of short term EE
• Expensive
• Time consuming: not for large-scale studies
• Inability to simulate true free-living situation
CRITERION / DLW
Biochemical procedure that can estimate EE through
biological markers that reflect the rate of metabolism
in the body
CRITERION / DLW
• Ingestion of a standardized amount of 2 stable isotopes of
water: 18O en 2H
• The isotopes distribute themselves in equilibrium with the
body water
• Urine samples are collected at the beginning and end of
the measurement period
• Difference in elimination rates of the isotopes provide a
measure of CO2 production and therefore EE
CRITERION / DLW
• Accurate and valid measurement of EE
• Applicable for children and adults
• Induces no change in PA behavior
 usual movement pattern
• Expensive: not for large-scale studies
• Requires expertise
• No indication of PA pattern, only total EE
CRITERION / direct observation
Direct behavioral observation of the activities by
experienced observers
CRITERION / direct observation
• Classify PA behaviors into distinct categories that can
be quantified and analysed by using codes
• Numerous instruments or systems
 each designed for specific purposes
 each with specific protocols for use
• Mostly used for children or schools
CRITERION / DLW
• Excellent quantitative and qualitative information
 frequency, intensity, time, type and context
• Applicable for children
•
•
•
•
Time and labour intensive
Not appropriate in large-scale studies
Potential reactivity of subjects
Subjectivity of observers
 intensive training needed
Selection of an appropriate
assessment technique
SELECTION /
The selection of appropriate tool depends on the
characteristics of the…
A. Study
•
•
•
•
•
Research question
Design
Resources & budget
Sample size
…
B. Population
•
•
•
•
•
Age
Etnicity
Cognitive ability
Health status
…
C. Activities
•
•
•
•
•
Activity type
Activity domains
Instensities
Sports
…
SELECTION /
SELECTION /
SELECTION / combination
Intensity, frequency, duration
Type
Full spectrum
Overall and domain-specific PA and SB
EVALUATION / profiling
Create a more accurate and integrated image of an individuals PA
behavior using all the important PA components.
Health targets:
1.
2.
3.
4.
5.
PAL: ≥ 1.75 METs
MVPA: 30 min
Vigorous: 20 min
Steps: ≥ 10.000
Sedentary: ≤ 7h
PAL
Sedentary
MVPA
# Steps
Vigorous
EVALUATION / ‘bewegingsdriehoek’
EVALUATION / be critical
Don’t take all the data ‘for granted’…
 be critical and evaluate with subject.
- Reactivity
- Seasonality
- Specific pastimes
-…
KEY KNOWLEDGE /

What is a subjective, objective and criterion physical
activity assessment method?

What are de advantages and disadvantages of each
method?

When should I use a certain method?
THANK YOU FOR YOUR
ATTENTION!
QUESTIONS ?