Scaling Perceived Exertion

Psychophysiolgoy

• Relationship between physical stimuli & perceptual responses

• Relationship between body & mind

Exertional Mediators:Physiological

• Respiratory / metabolic– Ventilatory

• Peripheral– Acidosis

• Non specific– Hormones

Exertional Mediators:Psychological

• Emotion & mood

• Cognitive function

• Perceptual processes

• Social or situational

Modern Approaches

• Direct assessment– Study sensory response

• Scale sensations

• Magnitude estimates of perceived exertion– Interindividual comparisons not possible

• Catergory scaling – Interindividual comparisons

Borg (1961) 21-pt– 0– 1– 2– 3 Extremely light– 4– 5 Very light– 6– 7 Light– 8– 9 Rather light– 10– 11 Neither light or laborious– 12– 13 Rather laborious– 14– 15 Laborious– 16– 17 Very laborious– 18– 19 Extremely laborious– 20

21 – pt Studies

• Borg 1961: n = 12 • Cycling at 100, 300, 900, 1200kpm/min• RPE not linear with HR or Power

• Borg, Dahlstrom 1962: n = 28 (14 & 15)• Linear relationship with HR, PO

• Borg, Linderholm 1967: n = 61 males (18 to 79)

• HR declined with age at all Powers, • RPE equal or increased with age

Borg (1971) – 15 pt

– 6 – 7 Very, very light– 8– 9 Very light– 10– 11 Fairly light– 12– 13 Somewhat hard– 14– 15 Hard – 16– 17 Very hard– 18– 19 Very, very hard – 20

Borg (1985) – 15 pt

– 6 No exertion at all – 7 Extremely light– 8– 9 Very light– 10– 11 Light– 12– 13 Somewhat hard– 14– 15 Hard (heavy)– 16– 17 Very hard– 18– 19 Very, very hard – 20 Maximal exertion

15 – pt Studies

• Borg (1971): Linear relationship between HR, Power and RPE

• Noble et al. (1986): RPE is dependent on mode of exercise

Borg (1983) 10 - pt0 Nothing at all0.30.5 Extremely weak (just noticeable)1 Very weak1.52 Weak (light)2.53 Moderate4 5 Strong (heavy)67 Very strong8910 Extremely strong11 • Maximal

10 – pt Studies

Noble et al. 1983

• Blood lactate and RPE increase similarly with quadratic trend

• Muscle lactate increased with a cubic trend

• HR increased linearly

Omni Scale

1. Artist drew pictures: represent physical exertional state.

2. Stimulus given to subjects verbal description of made

3. 6 verbal cues collected for adults (easy and hard) and 6 for children (tired).

4. Pictures & cues placed at equal intervals in 0 to 10.

Omni Adult Walking

Omni Adult Cycling

Uses of RPE

Perceptually Regulated Exercise Prescription

• To define the cardio respiratory training zone

• Regulate training intensity

• Estimation – production paradigm

• Production only paradigm

Perceptual Estimation-Production Prescription

• RPE linked to clinical events during GXT

• Two stage process:

• ID target RPE estimated during a GXT

• RPE is then produced during exercise

RPE Estimation

• RPE taken at GXT stages

• Max VO2 identified

• E.g 70 & 85% max identified

• Training RPE identified

RPE Production

• Client titrates exercise intensity

• Related to high/low intensities on GXT

• Overload is ‘natural’

Perceptual Production-Only Prescription

• Recommended for normal subjects only

• Identify ‘known’ intenstiy for benefit– CV training– Weight loss

• Good evidence base for AnT – 12 – 14– 50 – 80%max

Examples of Other Scales

Clinical Subscales

The Angina Scale

1+ Light, barely noticeable

2+ Moderate, bothersome

3+ Severe, very uncomfortable

4+ Most severe pain ever experienced in the past

Gagge, Stolwijk, Hardy ACSM (1986)

Comfortable sensation (1967)

1 Comfortable

2 Slightly uncomfortable

3 Uncomfortable

4 Very uncomfortable

Clinical Guidelines & applications

Classification of PA intensityPollock et al. 1990 / ACSM 1995

Relative Intensity

Intensity   %VO2max   %HRmax   RPE

Very light <30 <35 <10

Light 30-49 35-59 10 to 11

Moderate 50-74 60-79 12 to 13

Heavy 75-84 80-89 14 to 16

Very heavy >85 >90 >16

RPE for RehabilitationBorg 1998

• Exercise should be started at 9 to 11

• After a while progress to 13

• When exercise is hard :15

it is too hard!!!

RPE for Cardiac patientsPhase IV (BACR 2006)

• Use of RPE during GXT

• Use of RPE during the exercise sessions

• Use of RPE at home-based activity in a recorded log:frequency, duration, intensity, self monitoring of pulse rate

• Warm-up at RPE 10 to 11 (that is “light”)

• Main exercise program at RPE 12 to 15 (that is “somewhat hard” to “hard”)

• In neuropathy use of RPE is recommended

RPE for Cardiac patientsPhase IV (BACR 2006)

It is important not to rely on any single indicator of exertion levels, such as RPE or pulse rate.

Participants signs and symptoms responding appropriately to the activity:

• Excessive breathlessness• Loss of quality of movement• Skin colour sweat rate

Clinical applications of RPE (ACSM 1997)

Disease 6-20 scale OMNI scale

Myocardial infarction 11 to 16 4 to 7

CABG or PTCA 12 to 14 5 to 6

Valvular heart disease 11 to 14 4 to 7

Congestive heart failure 11 to 16 4 to 7

Cardiac transplant 11 to 16 4 to 7

Hypertension 11 to 13 4 to 5

Pulmonary disease 11 to 13 4 to 5

Task

• What is the problem with exercise intensity and b-blockade?