Optimizing heart rate during exericise

Dr. Aashish ContractorHOD: Preventive Cardiology and Rehab, Asian Heart Inst.Medical Director, Standard Chartered Mumbai Marathon

What is Exercise Physiology?

Definitions

• Physiology: is a branch of biological science concerned with the function of organisms and their parts.

• Exercise physiology is a branch of physiology that deals with the functioning of the body during exercise.

Heart Anatomy

Cardiac OutputThe amount of blood pumped by the heart

each minute• Product of heart rate and stroke volume• Q = HR x SV

Heart rate = number of beats per minute Stroke volume = amount of blood ejected in each

beat 75 bpm x 70 mls/ beat = 5000 mls or 5

liters/min

Transition From Rest Exercise and Exercise Recovery

• Rapid increase in HR, SV, cardiac output

• Plateau in submaximal (below lactate threshold) exercise

• Recovery depends on: Duration and intensity of exercise Training state of subject

Cardiovascular Response to Endurance Training

• Maximum cardiac output increases

• Maximum stroke volume increases

• Maximum heart rate does not change

Lactate Threshold

Cardiovascular Conditioning

FrequencyFrequency

IntensityIntensity

TypeType

TimeTime

F I T T

Exercise ProgrammingComponentsCardiovascular

• Frequency- 3-5 days/week

• Intensity- 55/65% - 90% HR max 40/50% - 85% VO2R or HRR

• Duration- 20-60 min of continuous or intermittent (minimum 10 min bouts)

• Mode- uses large muscle groups, maintained continuously, and rhythmical in nature

Intensity• Intensity refers to how hard the body is

working during exercise.

• Needs to be sufficient to overload the body in order to achieve a training effect.

• Common ways for deciding the intensity would be by using Age predicted formula Karvonen formula Functional capacity (MET system)

• Age predicted formula :

HRmax = 220 – Age

• Karvonen method : Using Heart Rate Reserve (HRR) to calculate intensity

HRR = MHR – RHR

Target HR intensity = Target % HRR + RHR

Guidelines for choosing intensity

• To experience benefits of cardiovascular exercise one must work at an intensity of

50 % - 85 % of VO2max (MET system) 50 % - 85 % of HRR method 60 % - 90 % of HRmax

Monitoring Intensity

• Heart rate method

• RPE scale

• Talk test method

Heart RateDepending on the person’s level of fitness,

calculate the Target heart rate intensity range by using the Age predicted formula or the Karvonen method and accordingly ask the client to maintain his exercise intensity in that range.

Rate of Perceived Exertion (RPE)

• Indicates a quantitative feeling of fatigue

• Used to regulate exercise intensity

Borg RPE Scale• 6

• 7 very , very light

• 8

• 9 very light

• 10

• 11 fairly light

• 12

• 13 somewhat hard

• 14

• 14 hard

• 16

• 17 very hard

• 18

• 19 very, very hard

• 20

Talk Test

• This simple test indicates if an individual is working at an appropriate intensity by whether or not he or she can converse while exercising. Breathing should be rhythmical and comfortable. If the person is gasping for breath between words then exercise intensity is too high.