Biometric measurements

HRV stands for Heart Rate Variability, which is the difference in time intervals between separate heartbeats. HRV relates to the autonomic nervous system that regulates body functions without conscious effort. HRV can be significantly influenced by age, race, sex, physical fitness, clinical conditions, and drug treatment. But 24-hour HRV appears to be stable when measured on a day-to-day basis and over periods of days to weeks. HRV is low with (physical) stress where the heart rhythm becomes more regular. A healthy heartbeat, however, contains healthy irregularities. This means that illness, bad sleep, a bad lifestyle, dehydration, or overtraining can lower HRV. On the other hand, a clear head, a healthy lifestyle with a good night’s sleep and a balanced physical training scheme can give a clear improvement in HRV.

RHR stands for Resting Heart Rate, which is the number of heart beats per minute. RHR can be significantly influenced by age, sex, physical fitness, clinical conditions, and drug treatment. But RHR appears to be stable when measured on a day-to-day basis and over periods of days to weeks. While a normal RHR does not mean that a person is free of health problems, a higher RHR can be related to illness (including heart diseases), bad sleep, a bad lifestyle (resulting in the metabolic syndrome), dehydration, or overtraining. A ‘normal’ RHR lies between 60 to 100 bpm, where aerobic exercise, such as running or cycling can lower it, as low as 40 bpm, or even lower. This because a well-trained heart is able to pump out more blood per heartbeat. Elite athletes often keep track of their RHR, where, after intensive exercise, a pulse of 10 (or more) bpm above the usual can be an indicator for overtraining, which will need more recovery time. When not intensively exercising, a low RHR, in combination with symptoms of dizziness and shortness of breath, can be related to a variety of heart diseases, which should be discussed with a physician.

SpO2 stands for ‘saturation of peripheral oxygen’, which is the percentage of how much oxygen the red blood cells in the body’s arteries are carrying. A normal SpO2 is between 95 and 100% and anything between 90% is considered to be abnormal. There are several health conditions that can be related to low oxygen saturation. People, suffering from Chronic diseases like COPD (Chronic Obstructive Pulmonary Disease) can have a lower saturation, where a further decreasing trend can be a sign of worsening (exacerbation) of the disease.

Sleep apnea is a serious sleep disorder that occurs when a person's breathing is interrupted during sleep. Sleep apnea can, if not well-treated lead to high blood pressure, stroke, heart failure, heart rhythm disorders like sick sinus syndrome or atrial fibrillation, but also diabetes, impotence, depression, and headaches. Besides this sleep apnea will lead to concentration disturbances at work, school or while driving. Due to apnea oxygen levels may drop repeatedly by 3 or 4 percent and considered abnormal when they drop below 88%. In these cases, it can be useful to consult with a physician.

RR stands for Respiratory Rate, which is the number of breaths per minute. RR is, as all body signal metrics, highly individual and can be influenced by age, sex, physical fitness, clinical conditions, and drug treatment. But RR appears to be stable when measured on a day-to-day basis and over periods of days to weeks. 12-18-breaths per minute is considered to be normal.  While a normal RR does not mean that a person is free of health problems, a higher RR can be related to illness (including lung diseases as chronic obstructive pulmonary disease, but can also be a result of a cold), bad sleep, a bad lifestyle (resulting in the metabolic syndrome), dehydration, or overtraining. If the average RR should be below or especially higher, it can be useful to consult with a physician.