All clients receive regular BP testing as part of their tri-annual fitness evaluations. High BP and BP irregularities can be indicative of serious issues and should be evaluated by a medical professional no matter how badly you want to engage a client while they are still excited.
I’ve known a 38yr old who died of aneurysm and a 28yr old who died of minor heart defect during exercise – both tragedies could have been potentially avoided with regular basal health checks including BP.
In addition, be sure to ask if a client is taking medication for high blood pressure or hypertension as these medications will likely show low BP and heart rate even during exertion.
I too use a basic Omron automatic BP machine. Although I find the traditional BP cuff and stethoscope method more accurate, auditory cues can be hard to hear in a noisy gym.
Which clients? All of them during the initial assessment. I use either the manual method or my Omron machine using the appropriate cuff size. If the reading is more than 140/90 on either value, it’s back to the doc. If it is below but close I re-check to see a trend. If it stays close, I usually ask the client to bring it up next time they see their doctor.
If a client has uncontrolled high blood pressure, I will not train him or her. If it is controlled I ask the doctor for parameters for training. Medications usually need to be considered.