Studies consistently show that a resting heart rate of 60 beats per minute or lower is associated with less cardiovascular disease, lower mortality, and better immune system functioning. Regular aerobic training is the best-supported way to lower resting heart rate.
A resting heart rate of 60 bpm or lower appears to be the most favourable zone when it comes to cardiovascular disease and immune function. Multiple studies show that a higher resting heart rate, particularly from 80 beats per minute onwards, is associated with more cardiovascular disease and higher mortality, independently of other known risk factors. This is an association: the studies do not prove a direct cause-and-effect relationship, but the pattern is visible across multiple studies (PMID 23937816).
A lower resting heart rate also appears to be better for the immune system. In a cross-sectional study of 7,500 healthy adults, a person with a resting heart rate of 70 to 80 beats per minute had a 37% greater chance of reduced Natural Killer cell activity (a measure of how well the immune system is functioning) compared with someone with a resting heart rate of 60 or lower. At a resting heart rate of 80 or higher, that chance was even 55% greater. Here too, this is an association, not a proven cause (PMID 39399484).
A good way to lower resting heart rate is to exercise regularly. In people aged 55 and older who led sedentary lives, resting heart rate decreased through aerobic training. The more intense the training, the greater the effect: training at 66% of heart rate reserve had more effect than training at 33% (PMID 19554028). Broader fitness studies also confirm that people with higher cardiorespiratory fitness (measured as VO2-max, a measure of maximum oxygen consumption) consistently have a lower resting heart rate (PMID 33574441).
If you want to track your resting heart rate at home with a wearable, the choice of device matters. Of the brands tested, the Oura ring (generation 3 and 4) measured nocturnal resting heart rate most accurately, with a deviation of less than 2% compared with an ECG. Whoop was acceptable (approximately 3% deviation), but Polar and Garmin proved less reliable. This is relevant if you want to track trends in your resting heart rate (PMID 40834291).
In summary: there is no single official 'healthy' threshold cited by the studies, but the data consistently point in the same direction: the lower the resting heart rate, the more favourable the picture for both cardiovascular health and immune function. A resting heart rate of 60 beats per minute or lower is consistently the reference with the best outcomes in the research. Regular aerobic exercise is the best-supported way to get closer to that.
The claims are based on observational and cross-sectional research (associations, not RCTs for the risk associations), plus one exercise RCT in older adults and one validation study for wearables. No meta-analysis was used as a primary source. Causality has not been proven for most of the associations.