Respiratory volumes You need to learn the definitions and typical values. Tidal volume (TV) – the volume of air inspired or expired in one breath Frequency (F) – the number of breaths per minute Minute ventilation (VE) – the volume of air inspired or expired in one minute VE = TV x F You need to know typical values at rest and during exercise. At rest TV = 500ml (0.5L) F =12 – 15 breaths per minute VE = 6 – 7.5 L/min During exercise TV = up to 3 – 4L F = increases to max 40 – 60 breaths per minute. VE = Max 120 – 180l/min - dependant on size and aerobic fitness. Remember that during max intensity (anaerobic) activity F increases to a max value although the depth of breathing (TV) may be lower than higher level aerobic activity. This is due to the internal intercostals contracting to speed up breathing (see mechanics of breathing).