Your resting heart rate

Plenty of nurses have taken my pulse during physical exams, shouting out a number usually in the low 60s before recording it on my chart. They're taking my resting heart rate, which is the number of beats per minute your heart beats at rest. A resting heart rate between 60-90 beats per minute is considered normal. Many factors can affect your resting heart rate, such as activity level, stress, posture and even temperature.

Elite athletes commonly have lower resting heart rates, some as low as the high 20s. According to Chris Carmichael at Outside magazine, a lower resting heart rate is the side effect of aerobic fitness. However he says there's no real health or performance benefit associated with a lower resting heart rate -- for as many elite athletes with a resting rate in the 30s, there are just as many elite performers with a resting heart rate in the 50s.

You may just be splitting hairs comparing the ultra-low resting heart rates of elite athletes, but for ordinary folk across a wider spectrum of fitness levels, lowering that resting heart rate indicates strengthened heart muscle gained through aerobic training. Simply put, if your heart muscle is stronger, your heart rate decreases since your heart can pump blood more easily. This is a good thing says one research study, a bit dated from 1999. Northwestern University researchers followed the pulse rates of around 34,000 adults aged 18 to 74 years old for a total of 22 years. Relative risks for deaths from heart disease, cancer and all other risks increased as participants' resting heart rates increased.