An individual’s highest attainable Heart Rate Variability (HRV) is determined by fitness, age, gender, genetics, health, and environmental conditions.
Comparing HRV (Age, Gender, Level/Type of Athlete)
Research has shown that multiple factors affect/influence an individual's HRV, such as:
Age: Younger people (under 25) tend to have higher HRV than middle-aged or older (60+) people.
"For the most part, HRV decreases abruptly as people get older. The middle 50% of people age 20-25 usually have an average HRV in the 55-105 range, while people between age 60-65 tend to be between 25-45." - from Everything You Need to Know About Heart Rate Variability (HRV)
Gender: Males tend to have higher HRV than females.
Athletic Level: Elite/professional athletes will have greater HRV than the average person (or those who participate in casual/recreational athletics).
Athletic Type: Within Elite level athletes, endurance (ex: runners) athletes trend towards higher HRV than strength-based athletes.
However, it's important to remember that none of this is absolute.
Average heart rate variability chart (Based on Age)
While the HRV chart (above) shows what technically falls under the umbrella of normal HRV, determining "what is a good heart rate variability?" requires a bit more in-depth analysis. And the answer? It varies. To understand why, read our Locker post: What is a Good HRV? It Varies For Everyone
Related resources: Normal Heart Rate Variability: Average HRV by Age and Gender