Freqüência cardíaca máxima em idosas brasileiras: uma comparação entre valores medidos e previstos

Abstract

SummaryObjective: 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.

Comparação da freqüência cardíaca máxima medida com as fórmulas de predição propostas por Karvonen e Tanaka

“…However, in the age range of our study sample (12-69 years), measured HRmax values were significantly lower (p < 0.000) than those of prediction equations.In subjects with poor fitness level, the use of regressions to indirectly estimate HRmax on a cycle ergometer potentially increases prediction errors and thereby exercise intensity, suggesting that HRmax should be measured directly for each subject 8 . The good correlation found in our study (r = 0.72) between measured HRmax and that estimated by Karvonen's and Tanaka's prediction equations may be explained by the greater number of patients and also by the fact that the tests were performed on a treadmill, rather than on a bicycle ergometer 16 . In a study comparing measured HRmax with that derived from prediction equations, Vasconcelos 17 postulated that the 220 -age formula 9 is more correlated with measured HRmax than that proposed by Inbar et al 18 .…”

Dose–Response Matters! – A Perspective on the Exercise Prescription in Exercise–Cognition Research

“…With regard to the second objection, it is worth mentioning that graded exercise tests are relatively complex and time consuming and that exercise intensity could be more easily determined by using specific formulas (e.g., Karvonen formula to determine a target heart rate) (Karvonen and Vuorimaa, 1988; Tanaka et al, 2001; Gellish et al, 2007; Zhu et al, 2010; Nes et al, 2013; Shargal et al, 2015). However, a graded exercise test should be an integral part of the process of a proper exercise prescription because, currently, exercise intensity cannot be accurately predicted by specific formulas (Strzelczyk et al, 2001; Robergs and Landwehr, 2002; Silva et al, 2007; Sarzynski et al, 2013; Correa Mesa et al, 2015; Esco et al, 2015; Arena et al, 2016), and a fixed percentage of a maximally achievable value of heart rate leads to a considerable amount of interindividual heterogeneity in metabolic responses (e.g., blood lactate) (Meyer et al, 1999), which is deemed to contribute, at least partly, to the interindividual heterogeneity in neurocognitive outcomes (see previous sections).…”

The Contribution of Functional Magnetic Resonance Imaging to the Understanding of the Effects of Acute Physical Exercise on Cognition

“…In addition, future studies should pay more attention to a more accurate prescription of exercise intensity because eight out of fourteen studies reviewed determined exercise intensity by using specific formulas to calculate the target heart rate [39,[71][72][73]105,106] or used subjective ratings of the perceived exertion [102,103]. In particular, the use of specific formulas is less than optimal because such an approach cannot accurately predict exercise intensity [152][153][154][155][156][157][158]. Thus, in order to determine exercise intensity (or load) more accurately, it is recommended to conduct a graded exercise test for endurance exercise or to quantify the one-repetition maximum (1-RM) for resistance exercises in a separate testing session.…”