Final answer:
Residency training durations range from 3 to 10 years, with the exact length depending on the medical specialty being pursued.
Step-by-step explanation:
Residency training varies in length depending on the specialty. For instance, cardiologists undergo four years of medical school followed by a three-year residency in internal medicine and then an additional three or more years specializing in cardiology. Similarly, reproductive endocrinologists complete a four-year residency in obstetrics and gynecology, then a three-year fellowship in reproductive endocrinology. Overall, residency can last anywhere from 3 to 10 years, based on the specialty and the subsequent fellowship training required for certain fields.