Target Heart Rate

The concept of maximum heart rate emerged in the 1930s with cardiovascular research. Early studies noted heart rate increased with exercise and plateaued at maximum effort. The relationship with age was recognized by the 1940s. The famous "220 minus age" formula's origin is unclear - it appeared in medical literature in the 1970s without citation. It's remarkably persistent despite known limitations. Robergs and Landwehr's 2002 review questioned its accuracy, while Tanaka and colleagues in 2001 proposed 208 - (0.7 x age) as a better alternative. The Karvonen formula was published in 1957 by Finnish physiologist Martti Karvonen. His method using heart rate reserve became popular in the 1970s-80s with the jogging boom. It's still considered more accurate for individualized training than simple percentage of max HR. Polar introduced the first wireless heart rate monitor for consumers in 1982, transforming how athletes trained. By the 2000s, HR monitoring became standard in serious training programs across all endurance sports. Modern understanding recognizes large individual variation in max HR (±10-15 bpm from formulas) and the importance of perceived exertion alongside HR data. Elite coaches use lactate testing and VO2 max assessment rather than age-based formulas for precise zone prescription.