Prescription Variables (FITT-VP Framework)

• Intensity of Exertion ("I = intensity" in FITT-VP)
  • The rate of energy demand for exertion
    • Measured in MET, Heart rate, Velocity, Load, RPE
      
  • DANGER!! Intensity is the most dangerous exercise component of exercise prescription. Severe injury can quickly occur, even death for diseased populations can occur with misprescription of this variable.
     
• Duration of Exertion ("T = Time in FITT-VP)
  • The time an exertion level is required
    • Measured in seconds, minutes, hours
  • Duration is next most dangerous. This is true if the mode has been appropriately selected, if not, the rapid occurrence of muscoskeletal injury exists with misprescription.
     
• Frequency of Exertion ("F = Frequency" in FITT-VP)
  • How often an exertion event is conducted
    • Measured in number of times per hour, day, week
  • Slower development of injury, Chronic Injury potential exists
     
• Mode of Exertion ("T = Type" in FITT-VP)
  • What is the individual doing to stress physiological systems
    • Analysis of major stressing characteristics of mode -- joint, muscle, cardiovascular system ...
       
• Volume of Exertion ("V = Volume" of FITT-VP prescription)
  • Volume is determined by the multiplication of the prescription variables of Intensity, Time, and Frequency. The Type (mode) tells you the location and type load, demand.
    • The combined loading of FIT variables on the human system can quickly lead to negative prescription outcomes if not carefully considered together.
       
      
Progression of Exertion ("P= Progression" of FITT-VP prescription)
• Progression is the rate you increase the variables of Frequency, Intensity, & Time (FIT) in the prescription.
  • The rate of change in FIT variables is directly proportional to the stress placed on the body -- joint, muscle, physiological  systems -- directly effecting levels of fatigue, soreness, and injury levels.