RPE is the best subjective estimate of ongoing exercise across all population .
Instruments donot calculate ,decipher or guide as our brain does to all the sensory inputs it receives from musculoskeletal,gastrointestinal, endocrinal , respiratory and metabolic pathways . It measures the FEEL … A combination of what the above systems are going through with the central motor commands on the feedbacks .

It benefits recreational runners as it’s free,easy to follow and practice on the run without stopping .it cross checks with heart rate (HR ) when all of us calculate 220- age , a vague , theoretical formula which donot correlate well with age .
For those who doubt which they shouldn’t … A meta analysis of 64 studies show a strong correlation with physiological variables like HR ,lactate ,%vo2 Max .
It correlates the best with ventilation and respiratory rate , the most reliable reflection of aerobic exercise intensity .it can be used while progession of exercises, to monitor, to perform aerobic or resistance training efficiently .

RPE is a 20 category scale but 0- 10 is used . Also known as Borg scale .the popular talk test is pure physiology .
Though till date no perfect one scale exist to help endurance athletes

RPE in my opinion is better placed because
: the studies conducted had max number of participants.
:it has linear correlation with multiple physiological parameters
:not always can you measure HR
:runners on medication… Hormonal , anti diabetic or anti hypertensive alter metabolic and
Cardiovascular responses should follow RPE diligently.
:True MHR till date is not accurately defined , diminishes with age ,varies with intensity ,
Weather and terrain .

If RPE is higher and heart rate in training zone ………. You are overtraining

If RPE and HR are lower than usual training zone …….your adaptation are improving .

If RPE and HR are lower on increasing cadence ……. Your running economy is improving .

If RPE is oddly higher for training zone ……..your body is warning you to stop .

If RPE is less for the training zone …………….your body is ready to push-up efforts .
Devices fail here .

Runners with positive history of hypertension,coronary artery disease , smoker , type A personality ,overweight ,with work stress .etc
Follow RPE …. There is no conflict of interest with running devices .

Dr Arvind Gupta .