First, How is recovery heart rate defined and measured?
Second, What are good to poor values for comparison?
Again, this is something that is subjective and going to vary from person to person.
I generally monitor my HR a few times during the week first thing when I wake up, and occasionally when I'm just sitting around watching TV. These will give you baselines. When I finish a workout, I'll take my HR immediately, and once again in a minute or two. These are what you compare to when you are checking it.
What you are looking for is a consistent drop. If your HR stays elevated compared to your normal trend, then you may be tired, had a harder workout than usual, weather is different, you had too much caffeine that day, etc etc. HR is a metric that is highly variable depending on a lot of conditions.
For me personally, my morning resting HR is about the only one I pay attention to on a consistent basis. If it's elevated for a few days over what is normal, then I know something is off.
HR is not one of my favorite training metrics to use, as there are so many different variables that can affect it day to day, or even hour to hour.
According to this article:
heart-rate recovery is defined as the decrease in person's heart rate, measured 1 minute after peak exercise
with "peak exercise" described as being as strenuous as possible, possibly even larger than the theoretical maximum heart rate (220 - age).
The article also defines a certain cut-off point: recovery rate of less than 12 bpm (in 1 minute) after peak exercise as being an indicator of poor cardiovascular health, with recovery rate of 20 to 30 being the "sweet spot":
For example, the chart shows that heart rate recovery of ~10 bpm suggests ~4 times larger risk than the baseline (2 to 7 times with 95% confidence).
The article also defined "peak exercise" as being as strenuous as possible, possibly even larger than the theoretical heart rate reserve:
The patients were encouraged to reach symptom-limited maximal exercise; the achievement of the target heart rate (based on age) alone was not a sufficient reason for the termination of testing.
However, the article which describes the experiment notes that patients with abnormal heart-rate recovery also had other indicators of poor cardiovascular health, meaning the cause-effect relationship might not be so clear:
As compared with the patients with a normal value for heart-rate recovery, those with an abnormal value (≤12 beats per minute) were older, had higher resting heart rates, were more likely to have hypertension or diabetes, were more likely to smoke, and were more likely to have Q waves on the electrocardiogram or a history of coronary artery disease. They were also more likely to take nondihydropyridine calcium-channel blockers or vasodilators.
Increasing levels of physical fitness were strongly correlated with decreasing rates of abnormal values for the recovery of heart rate among men and women.
Which suggests that achieving higher levels of fitness might increase the heart rate recovery value and help reduce the health risks, as most studies suggest anyway. Athletes and fitter persons might have heart recovery rates larger than 30 bpm.
Normal heart rate recovery is a decrease in your hr of 20-25 bpm (in 1 minute). For a fitter person it would be 30-45 bpm (in 1 minute). Abnormal heart rate recovery is usually defined as 12 or fewer bpm (in 1 minute).
For the number 12 this is the ref
Directly from RestWise.com:
Sports science has confirmed the link between variation in resting heart rate and overtraining. But this link is neither easily understood nor directly correlated. The problem is that an elevated resting heart rate can indicate training stress... but it can also simply mean that you had a rough day at work. To complicate matters, an elevated pulse may be a sign of sympathetic overtraining, whereas a dramatically lowered pulse may indicate parasympathetic stress. Restwise analyzes resting heart rate variability within the context of both your heart rate history and your other daily inputs. Our algorithm then distills this complexity and adjusts the calculation.
Resting heart rate should ideally be monitored during sleep or first thing in the morning, before getting out of bed. Day-to-day variations in resting heart rate of approximately 5% are common and not usually associated with fatigue or stress. However, increases of greater than 5% are typically reported in fatigued or acutely over-reached (sympathetic) individuals.