Heart Rate versus %O2max: Age, Sex, Race, Initial Fitness, and Training Response???HERITAGE

PURPOSE: In the HERITAGE Family Study, heart rate (HR) associated with various percentages of maximal oxygen intake (VO2max) was used to prescribe exercise intensity. When fitness improved, HR at the same power output (PO) decreased, and PO was increased to produce the prescribed HR. Although we assumed that subjects were again working at the same %VO2max, there were no studies with a large heterogeneous population to determine whether this was correct. METHODS: Therefore, 653 subjects with complete data were classified by age, sex, race, initial VO2max, and VO2max response after 20 wk of training. RESULTS: All groups had a significant increase in VO2max and a significant decrease in HR at the same absolute PO after training but no difference in HR at the same relative intensity. CONCLUSIONS: Training does not affect HR at a given %VO2max in a heterogeneous population of men and women, blacks and whites aged 17-65 yr with different initial VO2max values and different responses to training.