HIIT – High Intensity Interval Training & HIRT – High Intensity Resistance Training
Alternating periods of high intensity exercise with periods of rest or active recovery is well established as a training method that if highly effective for increasing fitness. The work intervals can range from 20seconds to several minutes. The recovery intervals usually range from 10 seconds to several minutes and can involve total rest (i.e. standing, seated or lying) or more commonly active recovery where lower intensity exercise is performed (i.e. walking(.
HIIT is a cardiovascular exercise strategy alternating short periods of intense anaerobic exercise with less intense recovery periods. The exercise usually does not involve any added resistance so examples are running, cycling, swimming, rowing, but can also include bodyweight exercises such as squats, lunges, pushups, stepups etc. Intervals can be based on time e.g. 40 seconds on and 20 seconds off or distance or Calories. Work intervals may be based on repetitions e.g. 12 repetitions then 30 seconds recovery.
HIRT is a strength and power exercise strategy alternating short periods of intense resistance exercise with less intense recovery periods. As for HIIT intervals can be based on time or number of repetitions. A key difference is that HIRT involves exercises often with additional load such as dumbbells, barbells, kettlebells, etc. so that the repetitions possible are more limited and load on the neuromuscular system is more intense to drive muscle growth, strength and power increase over cardiorespiratory capacity.