Maxium Heart Rate (MHR) calculator Basic Formula:
   MHR = FHR - age
Where:
   FHR: Fetal Heart Rate, 220 beats/min for men and 226 beats/min for women
   MHR: Maxium Heart Rate, in beats/min

Maxium Heart Rate Heil Formula:
   MHR = 211.415 - 0.5 * age - 0.05 * w + 4.5
Where:
   w: Body weight, in pounds (lbs)
   age: in years
   MHR: Maxium Heart Rate, in beats/min

Target Heart Rate calculation by Karvonen method:
   THR = (MHR - RHR) + RHR * 1.25;
Where:
   MHR: Maxium Heart Rate, in beats/min
   RHR: Rest Heart Rate, in beats/min
   THR: Target Heart Rate, in beats/min