I have two other HR monitors, a chest strap and an optical arm band (Wahoo Ticker Fit?). When cycling, both of these seem to provide the same or very close readings. The watch is consistently low. Often as much as 10 to 15 bpm low on the average of a 2+ hour bike ride. The instantaneous readings are all over the place. If you look at the graphs for the activity, It seems the watch is measuring something completely different. I have not made the effort to compare during activities other the bicycling. My two major disappointments with the watch are accuracy of HR and very poor battery life.
I upgraded from a VivoSmart and found that both the VivoSmart and the VivoActive 4 are reading lower than actual. I rely on my tracker to keep me from over working and find that running between 20 - 30 bpm is enough differences to be concerned for. Hope there is a fix soon enough or an ability to adjust to low readings.
Don't worry, Ive had it since it was released and I've had to reset, reboot, and problem solve this thing from day one. It is a VERY stupid watch by todays standards, you need to constantly tell it what you are doing, take a walk? Press a button, work in the garden? Press a button....If you forget to press that activity button beforehand, your heartrate will never align with actual bpm... My test showed that when taking a walk (without pressing a button) the heart rate showed 80-100bpm during a 30min walk.. The same route, with "walk" activity activated, my bpm was between 85-135 bpm.
The main point here is you will never get reliable heart rate data, the foundation for all other metrics on the device. My suggestion to anyone who wants more accurate information and less headache, get a smart watch instead. They've got more computional power and are better able to record and interpret your heart rate and movent. On these watches all your exercise is recorded with much more precision, without the need to micromanage any settings...
One more note on Vivoactive 4s, it is leaking RF emissions. Basically bleeding bluetooth radiation into your body, even when you dont connect it to a phone, it is "listening" all the time.
The Garmin representatives wont answer this question when asked, they are very careful to say "you can turn of the bluetooth connection from your watch" Great! When I asked if this action represents an airplane mode, i.e. all RF radios turn off. All I get from Garmin is crickets... Later it was revealed by other users that this watch never stops "listening" i.e bluetooth always emitting frequencies...
First choice in a smart watch, get a safe device with an "Airplane mode" under law these devices kill all RF activity and your body is protected from this harmful radiation....
These companies will never have your best interest at heart, their only purpose is to make money and your health is not even on the roadmap...If it was, Garmin would conduct and publish a wealth of research papers and science regarding their products and their actual effects on the human body..
The question of harm to biological systems due to low-power ionizing and non-ionizing radiation is not settled. Controversy continues about possible non-heating effects of low-power non-ionizing radiation, such as non-heating microwave and radio wave exposure.- Wikipedia
The only reason this is not yet settled is.... No company wants to prove their products are harmful to your health...
The effects of long term microwave radiation exposure upon the body have been observed in countless studies. Long-term exposure to microwave radiation has been linked to:
cancer
leukemia
brain tumors
alzheimer's
autism
ADD
miscarriages
birth defects
autoimmune illnesses
multiple sclerosis
hair loss
suicide
Non-Thermal microwave radiation has been shown to affect biological changes within the body. These biological changes happen on a cellular level and their effects can be passed on to offspring via genetic damage (DNA, RNA).
Research published by National Institues of Health (https://www.nih.gov)
Low intensity microwave radiation induced oxidative stress, inflammatory response and DNA damage in rat brain.
"In conclusion, the present study suggests that low intensity microwave radiation induces oxidative stress, inflammatory response and DNA damage in brain by exerting a frequency dependent effect. The study also indicates that increased oxidative stress and inflammatory response might be the factors involved in DNA damage following low intensity microwave exposure."
Radiation induced oxidative and nitrosative stress results in the hippocampal neuronal and nonneuronal apoptosis via the oxidative damage of cellular constituents.
"Our findings, in brief, conclude that the MW radiation induced oxidative and nitrosative stress results in the hippocampal neuronal and nonneuronal apoptosis via the oxidative damage of cellular constituents (viz. nucleic acids, proteins, and lipids) and subsequent overexpression of p53 which upregulate Bax as well as downregulate pro-Caspase-3 and full length/uncleaved PARP-1 which eventually lead to neuronal degeneration via apoptosis. As the duration of the chronic exposure (2 h/day) increases, 2.45 GHz (CW) MW irradiation mediates neuronal and nonneuronal cell death/apoptosis more severely."
Microwave frequency electromagnetic fields (EMFs) produce widespread neuropsychiatric effects including depression.
"Two U.S. government reports from the 1970s to 1980s provide evidence for many neuropsychiatric effects of non-thermal microwave EMFs, based on occupational exposure studies. 18 more recent epidemiological studies, provide substantial evidence that microwave EMFs from cell/mobile phone base stations, excessive cell/mobile phone usage and from wireless smart meters can each produce similar patterns of neuropsychiatric effects, with several of these studies showing clear dose–response relationships. Lesser evidence from 6 additional studies suggests that short wave, radio station, occupational and digital TV antenna exposures may produce similar neuropsychiatric effects. Among the more commonly reported changes are sleep disturbance/insomnia, headache, depression/depressive symptoms, fatigue/tiredness, dysesthesia, concentration/attention dysfunction, memory changes, dizziness, irritability, loss of appetite/body weight, restlessness/anxiety, nausea, skin burning/tingling/dermographism and EEG changes. In summary, then, the mechanism of action of microwave EMFs, the role of the VGCCs in the brain, the impact of non-thermal EMFs on the brain, extensive epidemiological studies performed over the past 50 years, and five criteria testing for causality, all collectively show that various non-thermal microwave EMF exposures produce diverse neuropsychiatric effects."
