title: Maximal heart rate in soccer players: measured versus age-predicted.
abstract: BACKGROUND
  Although maximal heart rate (HR max) is widely used to assess exercise intensity in sport training, and particularly in soccer, there are limited data with regards to the use of age-based prediction equations of HR max in soccer players. The aim of this study was to compare the measured-HR max with two prediction equations (Fox-HR max = 220 - age and Tanaka-HR max = 208 - 0.7 × age) in soccer players.
  
  
  METHODS
  Adolescent (n = 162, 15.8 ± 1.5 years) and adult players (n = 158, 23.4 ± 4.6 years), all members of competitive clubs, voluntarily performed a graded exercise field test (Conconi protocol) to assess HR max .
  
  
  RESULTS
  The measured-HR max (197.6 ± 9.4 bpm in total, 200.2 ± 7.9 bpm in adolescent players, and 195.0 ± 10.0 bpm in adult players) was explained by the formula HR max = 212.3 - 0.75 × age (r = -0.41, standard error of the estimate = 8.6). In the total sample, Fox-HR max overestimated measured-HR max [mean difference (95% confidence intervals) = 2.8 bpm (1.6; 3.9)], while Tanaka-HR max underestimated HR max [-3.3 bpm (-4.5; -2.2)]. In adolescents, Fox-HR max overestimated measured-HR max [4.0 bpm (2.5; 5.5)] and Tanaka-HR max underestimated HR max [- 3.2 bpm (-4.7; -1.8)]. In adults, Tanaka-HR max underestimated HR max [-5.0 bpm (-5.3; -4.7)], while there was not any difference between Fox-HR max and measured-HR max [1.6 bpm (-3.4; 0.2)].
  
  
  CONCLUSIONS
  The results of this study failed to validate two widely used prediction equations in a large sample of soccer players, indicating the need for a sport-specific equation. On the other hand, the new equation that we presented should be investigated further by future studies before being adopted by coaches and fitness trainers.
authors.affiliation: Department of Physical and Cultural Education, Hellenic Army Academy, Attiki, Greece.
authors.forename: Pantelis T
authors.initials: PT
authors.lastname: Nikolaidis
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D010101:Oxygen Consumption / Q000502:physiology*; D011237:Predictive Value of Tests; D012916:Soccer; D055815:Young Adult