Maximum heart rate in Brazilian elderly women: comparing measured and predicted values.

OBJECTIVE

This study sought to compare maximum heart rate (HRmax) values measured during a graded exercise test (GXT) with those calculated from prediction equations in Brazilian elderly women.

METHODS

A treadmill maximal graded exercise test in accordance with the modified Bruce protocol was used to obtain reference values for maximum heart rate (HRmax) in 93 elderly women (mean age 67.1 +/- 5.16). Measured values were compared with those estimated from the "220-age" and Tanaka et al formulas using repeated-measures ANOVA. Correlation and agreement between measured and estimated values were tested. Also evaluated was the correlation between measured HRmax and volunteers age.

RESULTS

Results were as follows: 1) mean HRmax reached during GXT was 145.5 +/- 12,5 beats per minute (bpm); 2) both the "220-age" and Tanaka et al (2001) equations significantly overestimated (p < 0.001) HRmax by a mean difference of 7.4 and 15.5 bpm, respectively; 3) age was significantly (p < 0,001) and inversely related to measured HRmax.

CONCLUSION

Based on these results, it can be concluded that both prediction equations significantly overestimated HRmax measured during maximal GXT in Brazilian elderly women, a finding that may have important implications when prescribing exercise intensity for this population. In addition, HRmax was inversely related to the volunteers age, suggesting that the chronotropic reserve continues to decline after age 60.