The Karvonen formula, which is widely used to estimate exercise intensity, contains maximum heart rate, H Rmax, as a variable. This study employed pedaling experiments to assess which of the proposed formulas for calc...The Karvonen formula, which is widely used to estimate exercise intensity, contains maximum heart rate, H Rmax, as a variable. This study employed pedaling experiments to assess which of the proposed formulas for calculating H Rmaxwas the most suitable for use with the Karvonen formula. First, two kinds of experiments involving an ergometer were performed: an all-in-one-day experiment that tested eight pedaling loads in one day, and a one-load-per-day experiment that tested one load per day for eight days.A comparison of the data on 7 subjects showed that the all-in-one-day type of experiment was better for assessing H Rmaxformulas,at least for the load levels tested in our experiments. A statistical analysis of the experimental data on 47 subjects showed two of the H Rmaxformulas to be suitable for use in the Karvonen formula to estimate exercise intensity for males in their 20 s. In addition, the physical characteristics of a person having the greatest impact on exercise intensity were determined.展开更多
Aim:Myasthenia gravis(MG)is a neuromuscular transmission disorder caused by acetylcholine receptor autoantibodies.Cardiac autonomic dysfunctions were rarely reported in patients with MG.Functional cardiac abnormalitie...Aim:Myasthenia gravis(MG)is a neuromuscular transmission disorder caused by acetylcholine receptor autoantibodies.Cardiac autonomic dysfunctions were rarely reported in patients with MG.Functional cardiac abnormalities were variable and reported in patients at severe stages of the disease and with thymoma.We investigated cardiac functions in patients with MG using Ambulatory 24‑h electrocardiographic Holter‑Monitoring.Methods:This study included 20 patients with MG with a mean age of 28.45±8.89 years and duration of illness of 3.52±1.15 years.The standard Holter reports include data for heart‑rate,ventricular ectopies(VEs),supraventricular ectopies(SVEs),heart-rate variability(HRV),ST,QT,atrial fibrillation and T‑wave alternans.Results:VEs,SVEs and ST‑T changes were reported in 55%,40%and 20%of patients respectively.Compared with healthy subjects(n=20),HRV components including SDNN,SDANN,SDNN Index,RMS‑SD and pNN50(P=0.001 for all)were reduced in patients indicating sympathetic and parasympathetic autonomic dysfunctions.HRV abnormalities were reported in 30-60%of patients.No significant correlations were identified between SDNN,RMS‑SD,pNN50,and duration of illness.Conclusion:Depressed HRV may be an early manifestation of autonomic neuropathy in patients with MG even in milder stages of the disease.This information is useful in rating disease progression and the efficacy of therapeutic interventions.展开更多
基金supported by Health Science Center Foundation,Japan
文摘The Karvonen formula, which is widely used to estimate exercise intensity, contains maximum heart rate, H Rmax, as a variable. This study employed pedaling experiments to assess which of the proposed formulas for calculating H Rmaxwas the most suitable for use with the Karvonen formula. First, two kinds of experiments involving an ergometer were performed: an all-in-one-day experiment that tested eight pedaling loads in one day, and a one-load-per-day experiment that tested one load per day for eight days.A comparison of the data on 7 subjects showed that the all-in-one-day type of experiment was better for assessing H Rmaxformulas,at least for the load levels tested in our experiments. A statistical analysis of the experimental data on 47 subjects showed two of the H Rmaxformulas to be suitable for use in the Karvonen formula to estimate exercise intensity for males in their 20 s. In addition, the physical characteristics of a person having the greatest impact on exercise intensity were determined.
文摘Aim:Myasthenia gravis(MG)is a neuromuscular transmission disorder caused by acetylcholine receptor autoantibodies.Cardiac autonomic dysfunctions were rarely reported in patients with MG.Functional cardiac abnormalities were variable and reported in patients at severe stages of the disease and with thymoma.We investigated cardiac functions in patients with MG using Ambulatory 24‑h electrocardiographic Holter‑Monitoring.Methods:This study included 20 patients with MG with a mean age of 28.45±8.89 years and duration of illness of 3.52±1.15 years.The standard Holter reports include data for heart‑rate,ventricular ectopies(VEs),supraventricular ectopies(SVEs),heart-rate variability(HRV),ST,QT,atrial fibrillation and T‑wave alternans.Results:VEs,SVEs and ST‑T changes were reported in 55%,40%and 20%of patients respectively.Compared with healthy subjects(n=20),HRV components including SDNN,SDANN,SDNN Index,RMS‑SD and pNN50(P=0.001 for all)were reduced in patients indicating sympathetic and parasympathetic autonomic dysfunctions.HRV abnormalities were reported in 30-60%of patients.No significant correlations were identified between SDNN,RMS‑SD,pNN50,and duration of illness.Conclusion:Depressed HRV may be an early manifestation of autonomic neuropathy in patients with MG even in milder stages of the disease.This information is useful in rating disease progression and the efficacy of therapeutic interventions.
